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MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-12
Figure 3-6: Diesel Unloading Arm at Delimara Power Station
Figure 3-7 is a satellite picture with a proposed lay-out superimposed. This lay-out shows one
60,000 m3 LNG storage tank at the reclaimed area next to the three diesel storage tanks right
below the cooling water inlet structure. Above the cooling water intake structure is the 500 meter
long berth. A new LNG loading arm and a vapour return arm have been placed in the middle of
the existing berth. A LNG pipe corridor leads from the unloading arm to the LNG storage tank.
The main LNG process area with (BOG blowers; De-Superheater vessel; HP Pumps and
Submerged Combustion Vaporizers) is placed in the empty space between unloading arm and
the existing cooling water inlet structure.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-13
Figure 3-7: Layout of LNG Terminal with one 60,000 m3 LNG Storage Tanks
The alternative layout option with two 30,000 m3 LNG storage tanks at the reclaimed area next
to the diesel tanks is shown in the following figure. Due to difficult soil condition it may not be
possible to build one large tank with a volume of 60,000 m3 and two smaller tanks have to be
built instead. In case of LNG being a solution considered in line with the expansion plan,
thorough assessment of geological conditions by sample drilling will have to be considered in
this regard.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-14
Figure 3-8: Layout of LNG Terminal with two 30,000 m³ LNG Storage Tanks
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-15
Nevertheless sample drilling which is a very extensive and costly measure and will not be exe-
cuted before a more advanced stage of regarding the potential realization of such an LNG ter-
minal.
Modification on the existing Installations
From a first visual inspection during a site visit the entire berth appears to be in good condition
and does not require major modifications or refurbishments. Only the existing mooring hooks
and mooring dolphins need to be checked if they are suitable for LNG vessels. It is anticipated
that only minor upgrading is required.
On the existing berth is an unloading arm for diesel fuel and a narrow pipe corridor to bring the
diesel to the storage tanks. These installations do not necessarily need to be removed if
Enemalta would like to retain a duel fuel capacity. Usage of diesel unloading equipment could
be continued during periods were no LNG unloading operation is ongoing.
Connection from LNG plant to the Marsa Power Station Site
The existing gas turbine at the Marsa Power plant is currently running on diesel fuel. A fuel
switch to natural gas is in principle possible; however natural gas has to be transported from the
Delimara power station to Marsa. The Marsa power generation units will continue to run on
diesel for the Base Demand Case Scenario. A fuel switch to natural gas is in principle possible;
however natural gas has to be transported from the Delimara power station to Marsa.
In order to avoid a costly 11.5 km long connection pipeline from Delimara to Marsa through po-
pulated areas the low quantity of gas required could be trucked from the pipeline landfall
terminal station in Delimara using specialised LNG trucks to the Marsa power station.
The turbines would have a daily consumption of about 180,000 m3 of natural gas which is the
equivalent of 300 m3 LNG, This would require a min. storage tank for LNG of about 600 m3 to
have a one day reserve.
A LNG truck trailer has a cargo capacity of roughly 43 m3 which would require an average of
7 trips. Each roundtrip would take about 3 hours i.e. one hour driving the distance of 30 km
(roundtrip) and one hour for loading and unloading. In total one complete cargo trip would take
no longer than 3 hours. This means that in theory 7 trips could be done within one day.
The picture below shows a typical LNG truck trailer. This particular trailer has a LNG cargo ca-
pacity of 43 m3.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-16
Figure 3-9: Typical LNG Truck Trailer with a Capacity of 43 m3
A simple cost calculation in Table 3-3 shows the cost involved.
Description Cost in Euro
LNG Truck Filling Station at the terminal 400,000,--
LNG Trailer with capacity of 43 m³ 220,000,--
LNG Storage Tank at Marsa Power Station (600m³) 420,000,--
Vaporizer and HP LNG Pump, piping etc. at Marsa Power Station 180,000,--
Civil Works at Marsa Power Station 110,000,--
Total Estimate 1,350,000,--
Table 3-3: Cost Calculation for LNG Supply at Marsa by Truck Trailer
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-17
However, it should be considered that the gas turbine at Marsa is not for base load power
generation and is only utilized during peak demand; therefore it is questionable if an additional
investment of 1.35 Mio EUR is justified for a fuel switch of a power generation unit that is used
to cover peak demand only.
3.1.3 Potential Hazards
Hazard identification for LNG terminal is conducted and the following hazards are identified:
LNG Spills;
Vapour Dispersion;
Thermal Radiation;
Environmental Impacts;
Ship Grounding and LNG Release;
Terrorism or sabotage;
Acts of Nature (storm, earthquake etc);
External Fire;
LNG Release due to Equipment or System Failure.
LNG Spill is one of the hazards discussed for LNG. The primary hazard of the flammable LNG is
the possibility of a fire. The two limiting conditions are an LNG release with and without
immediate ignition. If the ignition is immediate or relatively soon after the start of the release, the
fire size is determined by the LNG release rate which fuels the fire. If the ignition is delayed, an
LNG vapour cloud will develop and disperse as it expands and/or moves downwind. For ignition
to occur, the concentration of vapour in the atmosphere must be at less than 15% which is the
Upper Flammable Limit (UFL). At concentrations above the UFL, there is not enough air to
sustain combustion. As the cloud expands, eventually the concentration drops below 5% vapour
in the atmosphere. This concentration of 5% is the Lower Flammable Limit (LFL). At
concentrations below 5% vapour in the atmosphere there is not enough fuel to sustain
combustion. If ignition occurs, the area with concentrations at or above the lower flammable limit
(5%) will be at risk. The vapour cloud will burn back to the source of vapour. This source can be
either the release itself or a pool of LNG accumulated prior to ignition. From these scenarios
emerge two explicit requirements for the protection of the public beyond the boundaries of the
facility. These are the two “exclusion zones” which are required for facility siting. Specifically,
there are the “vapour dispersion exclusion zone” and the “thermal radiation exclusion zone”.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-18
Vapour Dispersion Hazards: When a release occurs, the LNG will vaporize as it comes into
contact with the relatively warm surfaces and atmosphere. The initial hazard following a release
comes from the LNG spreading over the surface and vaporizing as it absorbs heat. The vapour
generated will mix with air which begins the vapour dispersion process. It is possible to calculate
the theoretical distance the flammable concentration of a vapour cloud will travel and this
distance is called the Lower Flammable Limit (LFL) vapour dispersion isopleths. LFL distance
can be represented on a site plan as a ring of equal concentration. The isopleths for a LFL
vapour cloud must not go beyond the LNG facility boundaries or property that cannot or will not
have occupancies and thus result in a distinct hazard to the public. The hazard is not the vapour
itself, but the possibility that it could be ignited. If ignited, the vapour cloud will not expand any
further, but instead, will burn back to the vapour source. The LNG fire will continue to burn until
the fuel is consumed or the fire extinguished. An LNG vapour cloud, mixed with air will not
explode unless confined in an enclosure.
The vapour dispersion calculations for the LNG facility shall be performed in order to define the
vapour excursion from a design spill at each impoundment area.
Thermal Radiation Hazards: If a fire occurs, there will be radiant heat from the flame which
could cause personal injury, property damage and potentially secondary fires. The potential
personal injury of the public is the primary concern. The severity of the injury depends on the
intensity of the radiant heat, the exposure time and any protective factors such as clothing. The
intensity or thermal flux level is measured in kilowatts per square meter (kW/m2). This unit is
generally unfamiliar but if related to sunlight with a clear sky, direct sunlight radiant heat is about
1 to 1.5 kW/m2.
The limiting radiant heat restriction on general public exposure is 5 kW/m2 or, say, 5 times as
strong as sunlight. This is not instantly injurious but becomes quite uncomfortable fairly quickly.
Ultimately these flux levels can cause injury. Recent “real live person” experiments have shown
that 60 seconds at 5 kW/m2 is not injurious and does not cause continued discomfort after the
radiant heat exposure is discontinued. The duration of exposure factor allows time for an
exposed person to find protective shelter from the direct exposure and/or move away from the
fire. In summary, the 5 kW/m2 exposure limit provides a high level of safety.
The thermal radiation calculations for the LNG facility shall be performed for a full dike fire for
the storage tanks or a fire over the full extent of each impoundment area.
Environmental Impacts: Negative long-term environmental impact from an LNG release is
virtually non-existent. LNG is colourless, odourless, and non-toxic and leaves no residue after
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-19
evaporation. LNG (liquid) has a specific gravity in the range of 0.45; therefore it will float on
water. LNG and LNG vapour are not soluble in water which precludes water contamination. The
specific gravity of LNG vapour is 0.55. LNG vapours become buoyant at temperatures above a
value of -107 ºC. The buoyancy of the vapour enhances the dispersion in the atmosphere with
no long-term hazardous effects. One of the attractive features of natural gas is that, unlike an oil
spill, an LNG release does not require any environmental clean-up effort. Methane is considered
to be a greenhouse gas but there are no vapours released in normal operations as all systems
are vapour tight.
Potential damage to environmental and socio-economic components is limited to short-term
hazards to flora, fauna and humans in the immediate vicinity of the release. There are no LNG
or vapour releases as a result of normal operations. Any short term releases would be the result
of an accidental spill or component failure. The affected area would probably be in the cleared
area around the tanks and process, but certainly within the facility boundaries. For example, any
fish in the immediate vicinity (a few hundred meters) of an LNG ship release would unlikely be
frozen or otherwise harmed as any freezing of the water would be at the surface of the water.
The surface of the water will be at the melting temperature of the ice. The ice will soon melt and
the environment will return to normal with no residual trace of the incident. Likewise, any
animals or birds within the vapour dispersion or thermal radiation isopleths caused by a release
could be immediately harmed or killed. An animal may not recognize a visible fog (vapour cloud)
as a fire hazard and thus suffer if they are in the flammable cloud if it is ignited. If they were not
within the vapour cloud if ignited, they could escape. If an LNG pool on water is ignited (“pool
fire”), marine mammals will likely stay away. It should be noted that persons can and have run
faster than a flame front. Immediately after an LNG release, the area would be suitable for
animals and humans to use again. Local population (animals or people) and property should
sustain no long-term effects from an LNG release. The LNG facility is designed to contain any
incident on site or within the controlled property.
An environmental emergency plan is required. Comprehensive safety and environmental
procedures shall be prepared using the safety studies for code regulation compliance, analysis
of emergency scenarios and the final facility design.
Ship Grounding and LNG Spill: When evaluating the possibility of ship grounding at or near the
terminal, two factors must be considered: the physical features of the navigable area adjacent to
the waterfront and berth, and the speed and control of the LNG ship. The navigable waters
surrounding the LNG facility shall be sufficiently deep that grounding would require a loss of
ship’s propulsion or steerage that would cause the ship to leave the berth area. While grounding
is always possible, as the ship approaches the facility it shall be under control of a licensed pilot.
The manoeuvring for berthing and turning of the ship shall be assisted by tugs. The tugs shall
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-20
be able to control the movement of the ship and prevent grounding. The potential for damage in
the event of grounding shall be further mitigated by the ship’s reduced speed as it approached
the berth and its double hull.
Terrorism or sabotage: The possible scenarios of terrorism attack or sabotage shall be studied
in detail to define the necessary mitigation measures. However the chances of this type of threat
are remote for several reasons, including:
Terminal and shipping personnel are always screened before hiring.
Ship crews tend to be very stable as the jobs are considered to be very attractive. There
is very little turnover in terminal staffing.
Terrorists are more interested in “high profile” targets with strong symbolic value, or targets that
can cause mass casualties or severe economic damage. In general, LNG terminals are not
attractive targets due to their “low political profile”, difficulty of attack, and high level of security.
Acts of Nature: The possibility of a significant LNG release resulting from an act of nature, such
as a severe storm, ice storm, or earthquake is remote because the design requirements shall
take seismic, wind, and weather factors into account. The tanks shall be designed for the
seismic rating of the region, and the tank profile shall take into account the wind loads (both
typical and maximum) for the region. Equipment and structures shall be designed to withstand
the harshest recorded environment for the region. A lightening strike shall not affect the system,
unless it strikes a vent mast or other component that has a natural gas leak, creating a
methane-rich environment. Significant leaks should be detected by mandated safety systems
before they become a source of ignition. Such vent fires would be small and are easily
extinguished.
Should an act of nature cause a release, the result will be the same or less than other causes
previously cited. An LNG release would be impounded and the resulting vapour dispersion or
thermal radiation would be limited to the terminal site and not cause injury or damage to
adjacent property.
Acts of nature involving an LNG ship should be divided into two categories, predicted conditions,
and unpredicted events. A predicted condition would be high winds, hurricane, ice storm, etc.
Unpredicted acts would be those events that occur suddenly, such as earthquakes. The LNG
ship will not dock and, if docked, will undock and depart should the weather exceed the design
criteria. If extreme weather were predicted, the LNG ship’s officers would monitor the weather to
avoid being caught in restricted waters during the storm.
Unpredicted events of nature, such as earthquakes, present a different scenario. The worst
case would be the LNG ship breaking its moorings during a cargo discharge. Breaking moorings
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-21
occurred once in the past when a sudden 100-mph wind, called a “Sumatra,” blew the LNG
Aries off the dock while loading cargo in Bontang, Indonesia. In such a case, the unloading arms
would exceed their operational range and the automatic disconnection (PERC) system would
activate. A small amount of LNG would be released; probably not enough to even reach the
water. If the LNG ship broke all its moorings and propulsion was not available, the ship could
drift and either allied with the dock or with the ground. Allision at low speed would possibly be
sufficient to penetrate the outer hull but not sufficient to breach the cargo tanks. (Allision is a
relatively new term adopted by the marine regulators to indicate the impact of a moving ship
with a fixed “obstacle” that is not moving.) Other damage to the ship caused by events of nature
is not plausible due to the ship being designed to be seaworthy in all types of weather.
External Fire: The possibility of an LNG release caused by external events, such as a forest fire
or adjacent oil storage fire, is extremely remote because the facility is built from non-combustible
materials, mostly steel and concrete. Further, the facility shall be designed to contain vapour
dispersion and thermal radiation within the boundaries of the facility, as explained in detail
above. The critical components of the import terminal for both operation and safety are not
susceptible to even large fires at the distances provided by the exclusion zones and plant
boundaries. These components are predominantly fire resistant. All components containing LNG
are alloy steel externally insulated. The safety zones also work to isolate the facility and prevent
an external fire from threatening the facility. Storage tanks would be protected by the
impoundment dike, which would serve as a firebreak around the tank and process area.
Furthermore, the facility shall be equipped with an extensive fire fighting system, which can be
used to protect the facility from an external fire.
An escalating LNG release as the result of a fire within the plant is unlikely for the same reason.
Due to the flammable nature of LNG, terminal personnel are extremely safety conscious. While
accidents have occurred, they do not typically result in fires large enough to initiate a
subsequent release or emergency escalation. However, in the event of a fire initiating a release,
vapour dispersion would not be an issue because an ignition source would be immediately
present. A major release would be contained within the dike or sump and thermal radiation is
predictable and part of the risk assessment process. A vapour release that ignited would burn
until the fuel was consumed or the fire extinguished. In either case, the fire and thermal radiation
would be contained within the facility boundaries, minimizing the danger to the surrounding
area. The fire fighting systems should prevent the fire from spreading to storage tanks and
process equipment not directly involved in the initial incident. All storage tanks and systems are
sealed such that no fugitive vapours are present to be ignited.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-22
LNG Release Due to Equipment or System Failure: The most credible type of release is the
result of equipment or system leakage, such as a leaking valve seal or flange gasket. This type
of release is typically small and non-threatening. The probability of such a failure is greatest at
flanges or joints where components, pipes, and valves are connected and undergo temperature
changes. These small leaks are visible and easily repaired by facility personnel. The next level
of failure would be a leak associated with a piece of equipment. In this case, the equipment is
typically replaced in service by a “spare” component and secured for repairs.
The LNG facility shall be equipped with an extensive array of gas detection and flame detection
equipment. Small leaks shall be detected either visually, by trained personnel working in the
facility, or by the detection equipment. Small leaks and/or fires should be easily handled by
facility personnel, with assistance from the local fire department if necessary.
A system failure that generates a major release will have the same net effect as the other major
incidents evaluated above. A release will be contained and directed to a sump, thus mitigating
the extent of vapour dispersion. Should the vapour ignite, the thermal radiation will be mitigated
by the release’s containment in the sump. The fire will continue until the fuel is consumed or the
fire is extinguished. Damage will be confined to the terminal boundaries, including any controlled
areas outside the property lines.
The extensive Risk Assessment including HAZID, HAZOP, QRA and EIA shall be performed in
order to analyse in detail and in specific the effects of these defined possible hazards and the
related mitigation measures based on the following methodology:
Establishing the resulting LNG release from credible events;
Calculation of the area extent of the hazards (pool fire and vapour cloud);
Determining the potential exposures, primarily exposure of the public.
Determining the surrounding distances to which these significant hazards extend, the zone of
influence or “exclusion zone.” The purpose of the exclusion zone requirements is the protection
of the public (population and property) surrounding the facility. Protection and safety of the
facility itself is also covered, but the public safety requirements are so strict that the facility
protection is a secondary benefit.
Confirming that these zones of influence to not exceed the project codes and standards require-
ments.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-23
3.2 Economic Description of the Proposed Scheme for Case (I) and (II)
3.2.1 Investment Costs of Major Components
The below table provides the scheme’s investment cost in total and for each major component.
In total, the projects investment cost amounts to 102.1 Mio Euro (10% contingencies and 12%
contractors total profit, mark-up are included). The project duration regarding the recommended
two LNG tanks scheme (total storage capacity of 60,000 m³) is estimated at three years. The
disbursement schedule of the investment is shown in Table 3-5.
# Item
1
2
3
4
5
6
Construction Equipment
Total: 102,101
Overhead and Indirects
Home Office Services (EPC Contractor)
Investment Costs
in T EUR
Owner's Engineering Services 3,431
Specialty Contractors 45,458
851
2,174
2,941
Direct Cost (Labor, Materials & Subcontracts) 47,219
Table 3-4: Investment Cost of LNG Scheme Case (I) and (II)
Year n-3 n-2 n-1 n
Disbursement in % 35% 35% 30% Start Year
Table 3-5: Disbursement of the Investment Cost of LNG Scheme Case (I) and (II)
As illustrated in Figure 3-10 the two major proportions of the investment cost are:
(i) The Direct Cost which includes:
o Site Preparation and Improvement;
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-24
o Process Equipment; o Underground and Aboveground Pipelines;
o Underground and Aboveground Electric Equipment;
o Concrete, Instrumentation and Insulation;
o Over less cost intensive items.
(ii) The Specialty Contractors Cost which includes:
o LNG Tank Costs;
o Jetty Upgrades Costs;
o Dredging Costs;
o Over less cost intensive items.
46%
1%
2%
3%
3%
45%Direct Cost (Labor, Materials & Subcontracts)
Construction Equipment
Overhead and Indirects
Home Office Services (EPC Contractor)
Owner's Engineering Services
Specialty Contractors
Figure 3-10: Investment Cost Break Down of the LNG Scheme for Case (I) and (II)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-25
Ownership and Operating Structure.
Since the only customer of the LNG terminal appears to be Enemalta it would make sense that
the Owner and Operator of the LNG Terminal would be a subsidiary of Enemalta.
Regulatory Structure.
There are a number of options available for the Buyer on how to structure the supply of LNG
and on how to participate along the LNG value chain. The structure is mainly dependent on:
The sourcing structure (e.g. Point of sale, ex-ship, FOB);
The selected partner;
Desire of Buyer to move upstream;
Ability to invest and carry risk.
The identified options can be summarised in three categories as follows:
Ex-ship LNG supply to a Re-gas terminal in Malta;
FOB LNG supply from a terminal in a gas producing country (e.g. Algeria);
Participation along the entire value chain.
3.2.2 Operational and Maintenance Costs
LNG Price Estimation
LNG imports into Europe are generally linked to crude oil prices (i.e. Brent) but prices are a bit
more diverse in Europe as compared to Asia as LNG is competing with pipeline imports and to
some extent also with indigenous supply in many countries. LNG supply contracts are not a
public domain and the exact pricing formula for LNG is negotiated on a case by case basis.
Traditionally LNG supply contracts were all long term i.e. over a period of 20 years and are
usually indexed to a basket of competing fuels (i.e. crude oil; diesel etc). Recent changes in the
LNG market have trended towards increased flexibility. Contracts have loosened terms on both
price and volume, and can be negotiated for shorter periods of time. Additionally, flexibility in
LNG shipping has led to an increase in short-term contacts.
Traditionally the LNG price is expressed in USD/mBtu. The average LNG price in spring 2007
for LNG delivered to Spain was 6.3 USD/mBtu (Source: Argus Global LNG Services) which is
equivalent to a natural gas price of some 167 EUR/1000m³ or 223.3 EUR/t.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-26
Regarding the development of the LNG price an indexation of the crude oil price forecast of the
Energy Information Agency (EIA) was applied (for more details see chapter 6.2 within the Work
Package I Report).
Fixed O&M Costs
For the LNG terminal the fixed operation expenditures have been estimated as stated in the fol-
lowing table.
# Item
1
2
3
4
5
6
7
8
9 200 Insurance
Costs in T EUR/a
Management and Operation 960
Tugboat Operation Fees 160
50
820
20
Technical Assistance 220
Inspection
Total Annual Fixed OPEX: 2,480
Maintenance
Nitrogen
Telecommunication 20
Permits & other Fees 30
Table 3-6: Estimate of Annual Fixed OPEX
Variable O&M Costs
Variable OPEX are the throughput dependent cost of operating the LNG terminal. The biggest
expense is the cost for electricity. For the electricity consumption of the pumps and blowers a
price of 0.05 Euro/kWh was assumed.
Another cost item is related to the gas consumption of the regasification process. Assumption is
that heat will be recovered during the operation of DPS. Assuming a typical plant availability of
91%, during the remaining time period gas itself will be utilised to regasify the LNG. A quantum
of 0.14% of the sent-out is used as fuel gas using the price of 223.3 EUR/t.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-27
# Item
1
2
3
Costs in T EUR/a
Fuel Gas for LNG Vaporisation 184
Electricity for HP Pumpsand Blowers 1,550
Total Annual Variable OPEX: 1,739
Caustic Soda for Vaporisation 5
Table 3-7: Estimate of Annual Variable OPEX
3.2.3 Dynamic Unit Cost Assessment for Case (I) and (II)
The approach applied for the economic analysis of fuel supply options was explained in section
3.1.3. The calculation of the DUC is provided in the following charts.
Fuel supply figures are applied in accordance to the individual demand scenarios. Regarding
the high gas demand scenario (Case I) the DUC of the proposed LNG supply scheme amount to
23.8 EUR per tonne of fuel. The DUC are marginally higher (3%) for the base gas demand sce-
nario resulting in 24.4 EUR per tonne of fuel.
Finally a comparison of the DUC for both gas supply options investigated in this study is provi-
ded. The lowest cost occurs for the LNG scheme regarding the high gas demand scenario. Its
DUC are 9% lower compared with the DUC of the related pipeline scheme based on the same
demand projection.
Nearly the same result was evaluated for the base gas demand scenario. The DUC of the
pipeline scheme are 10% lower compared with the DUC of the related LNG scheme based on
the same demand projection.
Item Unit
LNG Scheme
high (Case I)
LNG Scheme
base (Case II)
Pipe Scheme
high (Case I)
Pipe Scheme
base (Case II)
PV Capital T EUR /a 116,320 116,320 139,090 139,090
PV OPEX T EUR /a 55,095 55,095 13,553 13,553
Dynamic Unit Cost EUR/t 23.8 24.4 25.9 26.8
Table 3-8: Dynamic Unit Cost of LNG and Pipeline Schemes
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 3-28
Table 3-9: Dynamic Unit Cost of the LNG Scheme - Case (I)
1
Ge
ne
ral
Info
rmati
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and
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igh
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T E
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n-3
n-2
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15
20
25
30
Investm
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Cost
T E
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35,7
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35,7
35
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,630
00
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Fix
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OP
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T E
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02
,480
2,4
80
2,4
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2,4
80
2,4
80
2,4
80
2,4
80
Va
ria
ble
OP
EX
T E
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/a
00
01
,739
1,7
39
1,7
39
1,7
39
1,7
39
1,7
39
1,7
39
Fu
el G
as S
up
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dt/
a0
00
49
0,7
09
51
7,5
39
54
6,6
81
58
0,2
92
613
,903
64
8,6
47
68
5,3
57
3
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Capital
T E
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/a
116,3
20
OP
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T E
UR
/a
55,0
95
Fu
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as S
up
plie
dt/
a7,2
16,3
29
4
Dyn
am
ic U
nit
Co
st
DU
C -
Gas S
up
ply
EU
R /
t23
.8
EU
R /
100
0m
³17
.7
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Table 3-10: Dynamic Unit Cost of the LNG Scheme - Case (II)
1
Gen
era
l In
form
ati
on
Ca
se:
Ga
s D
em
an
d S
cen
ario B
ase
To
tal In
ve
stm
ent
in T
EU
R10
2,1
01
Dis
cou
nt
Rate
6.5
%
Lifetim
e in
a30
Co
nstr
uctio
n P
erio
d in a
3
Sta
rt o
f O
pera
tion
20
11
2
Ca
sh
Flo
w
Ite
mY
ear
>>
n-3
n-2
n-1
15
10
15
20
25
30
Inve
stm
ent
Co
st
T E
UR
/a
35
,735
35
,735
30,6
30
00
00
00
0
Fix
ed O
PE
XT
EU
R /
a0
00
2,4
80
2,4
80
2,4
80
2,4
80
2,4
80
2,4
80
2,4
80
Va
riab
le O
PE
XT
EU
R /
a0
00
1,7
39
1,7
39
1,7
39
1,7
39
1,7
39
1,7
39
1,7
39
Fu
el G
as S
up
plie
dt/
a0
00
382
,042
488
,785
543
,302
57
6,3
00
609
,37
06
43
,857
680
,296
3
Pre
sen
t V
alu
e
Ca
pita
l T
EU
R /a
116
,320
OP
EX
T E
UR
/a
55,0
95
Fu
el G
as S
up
plie
dt/
a7
,012
,93
5
4
Dyn
am
ic U
nit
Co
st
DU
C -
Ga
s S
up
ply
EU
R /
t2
4.4
EU
R /
10
00
m³
18.3
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3.3 Technical Description of the Proposed Scheme for Case (III)
As it can be seen in Figure 2-1 (Section 2.1.1) the projected gas demand figures for the Low
Gas Demand Scenario is almost stagnant and actually declines slightly after the year 2020. Al-
though it is a very small gas demand we have calculated the CAPEX and OPEX figures for this
case.
The main difference in the design of the LNG terminal for Low Gas Demand Scenario is the size
of the LNG Storage tank. For this low gas demand we have taken the design sent-out of some
0.170 bcm/a and slightly higher volumes such as 0.200 bcm/a and 0.240 bcm/a to show the
sensitivities of the low gas demand scenario.
The vessel size was adopted for this low gas demand and vessels with a cargo volume of
5,000 m³; 10,000 m³ and 20,000m³ were selected. LNG vessels with a cargo volume of some
LNG Storage Required
13,80714,438
15,279
24,04124,672
25,513
29,158 29,78830,629
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
0.170 0.200 0.240Natural Gas Send Out (bcm/a)
LN
G S
tora
ge
Re
qu
ire
d (
m³)
10,000 m³ Ship 20,000 m³ Ship 25,000 m³ Ship
Figure 3-11: Required LNG onshore Storage vs. LNG vessel size
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20,000 m³ and below have a maximum length of 150 meters and a maximum draft of
7.6 meters. Therefore no dredging is required at the existing berth and the Delimara Power Sta-
tion.
General Data
LNG Storage Vessel Size 10,000 20,000 25,000 m³
LNG Storage Vessel Size (Net) 9,700 19,400 24,250 m³
4 days
Daily Send Out - Maximum (% over Nominal) 10%
Fuel Gas (% of Send Out) 2.0%
Low Gas Demand Scenario
Gas Send Out Flow Rate 0.17 0.17 0.17 bcm/year
Gas Send Out Flow Rate 512,329 512,329 512,329 m³/day (Gas)
Gas Send Out Flow Rate 830 830 830 m³/day (LNG)
Fuel Gas Flow Rate 17 17 17 m³/day (LNG)
Gas Send Out (Gross) 847 847 847 m³/day (LNG)
Reserve storage due to inclement weather/ship delays 3,388 3,388 3,388 m³
Sub-Total - Required Storage 13,088 22,788 27,638 m³
LNG Tank Heel 5.5% 720 1,253 1,520 m³
Storage Required 13,807 24,041 29,158 m³
Ship Frequency 11.5 22.9 28.6 days
Low Gas Demand Scenario
Gas Send Out Flow Rate 0.2 0.2 0.2 bcm/year
Gas Send Out Flow Rate 602,740 602,740 602,740 m³/day (Gas)
Gas Send Out Flow Rate 976 976 976 m³/day (LNG)
Fuel Gas Flow Rate 20 20 20 m³/day (LNG)
Gas Send Out (Gross) 996 996 996 m³/day (LNG)
Reserve storage due to inclement weather/ship delays 3,985 3,985 3,985 m³
Sub-Total - Required Storage 13,685 23,385 28,235 m³
LNG Tank Heel 5.5% 753 1,286 1,553 m³
Storage Required 14,438 24,672 29,788 m³
Ship Frequency 9.7 19.5 24.3 days
Low Gas Demand Scenario
Gas Send Out Flow Rate 0.24 0.24 0.24 bcm/year
Gas Send Out Flow Rate 723,288 723,288 723,288 m³/day (Gas)
Gas Send Out Flow Rate 1,172 1,172 1,172 m³/day (LNG)
Fuel Gas Flow Rate 24 24 24 m³/day (LNG)
Gas Send Out (Gross) 1,196 1,196 1,196 m³/day (LNG)
Reserve storage due to inclement weather/ship delays 4,783 4,783 4,783 m³
Sub-Total - Required Storage 14,483 24,183 29,033 m³
LNG Tank Heel 5.5% 797 1,330 1,597 m³
Storage Required 15,279 25,513 30,629 m³
Ship Frequency 8.1 16.2 20.3 days
Number of days to provide reserve storage due to inclement
weather/ship delays/plant operations/etc.
Table 3-11: Calculation for required LNG Storage Volume – Case (III)
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Looking at the graph in the figure above it is evident that the biggest factor in determining the
onshore storage requirements is the size of the vessel that supplies the LNG. It appears that a
LNG storage tank with 15,000 m³ is the optimum solution for the low gas demand scenario
based on a LNG supply vessel with a cargo volume of 10,000 m³. However, in reality it will be
difficult to secure a charter for a LNG vessel with 10,000 m³ cargo volume in the Mediterranean.
It is more likely to secure a charter of a 25,000 m³ LNG vessel. It is therefore recommended to
install a 30,000 m³ onshore storage tank for the low gas demand scenario.
Please note that partial unloading of LNG i.e. unloading of 25,000 m³ from a 60,000 m³ LNG
vessel is usually not allowed. LNG cargo vessels that are only partially filled are subject to the
so called sloshing effect that make a vessel instable during bad weather and also lead to higher
BOG rates during the journey.
Table 3-11 shows the general assumptions for the LNG storage tank calculations.
3.3.1 Basic Design
The basic design for Case (III) is the same as for Case (I) and (II)
3.3.2 Location
The location for Case (III) is the same as for Case (I) and (II).
3.3.3 Potential Hazards
The hazards and risk for Case (III) is the same as for Case (I) and (II).
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3.4 Economic Description of the Proposed Scheme for Case (III)
3.4.1 Investment Costs of Major Components
The below table provides the scheme’s investment cost in total and for each major component.
In total, the projects investment cost amounts to 75.7 Mio Euro (10% contingencies and 12%
contractors total profit, mark-up are included). The project duration regarding is estimated at
three years. The related disbursement schedule of the investment is shown in Table 3-13.
# Item
1
2
3
4
5
6
Investment Costs
in T EUR
Owner's Engineering Services 3,299
Specialty Contractors 22,944
876
2,237
2,730
Direct Cost (Labor, Materials & Subcontracts) 43,619
Construction Equipment
Total: 75,705
Overhead and Indirects
Home Office Services (EPC Contractor)
Table 3-12: Investment Cost of LNG Scheme Case (III)
Year n-3 n-2 n-1 n
Disbursement in % 35% 35% 30% Start Year
Table 3-13: Disbursement of the Investment Cost of LNG Scheme Case (III)
As illustrated in Figure 3-12 the dominating investment cost proportion are the direct cost which
includes:
o Site Preparation and Improvement;
o Process Equipment;
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o Underground and Aboveground Pipelines;
o Underground and Aboveground Electric Equipment;
o Concrete, Instrumentation and Insulation;
o Over less cost intensive items.
Nearly a third of the total investment is caused by the specialty contractors cost which includes:
o LNG Tank Costs;
o Jetty Upgrades Costs;
o Over less cost intensive items.
58%
1%
3%
4%4%
30%Direct Cost (Labor, Materials & Subcontracts)
Construction Equipment
Overhead and Indirects
Home Office Services (EPC Contractor)
Owner's Engineering Services
Specialty Contractors
Figure 3-12: Investment Cost Break Down of the LNG Scheme for Case (III)
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3.4.2 Operational and Maintenance Costs
LNG Price Estimation:
The price estimation and the approach regarding the price projection is described in the Section
3.2.1 of this report.
Fixed O&M Costs;
For the LNG terminal the fixed operation expenditures have been estimated as stated in the fol-
lowing table.
# Item
1
2
3
4
5
6
7
8
9
Inspection
Total Annual Fixed OPEX: 2,190
Maintenance
Nitrogen
Telecommunication 20
Permits & other Fees 30
Costs in T EUR/a
Management and Operation 960
Tugboat Operation Fees 80
40
690
20
Technical Assistance 200
150 Insurance
Table 3-14: Estimate of Annual Fixed OPEX
Variable O&M Costs
Variable OPEX are the throughput dependent cost of operating the LNG terminal. The biggest
expense is the fuel cost for the regasification process the LNG.
Assumption is that 1.5% of the sent-out is used as fuel gas using the price of 223.3 EUR/t. For
the electricity consumption of the pumps and blowers a price of 0.05 Euro/kWh was assumed.
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# Item
1
2
3
Costs in T EUR/a
Fuel Gas for LNG Vaporisation 37
Electricity for HP Pumpsand Blowers 520
Total Annual Variable OPEX: 559
Caustic Soda for Vaporisation 2
Table 3-15: Estimate of Annual Variable OPEX
3.4.3 Dynamic Unit Cost Assessment for Case (III)
Similar to the results of the assessment of the low gas demand scenario pipeline scheme the
DUC calculation brings out that the dynamic unit cost of the LNG scheme are extremely high.
While the Case (III) gas demand figures are substantially lower compared to the base scenario,
the CAPEX and OPEX of the scheme do not decrease in the same range. Finally the dynamic
unit costs are nearly three times higher (78.3 EUR/t compared to 24.4 EUR/t).
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Table 3-16: Dynamic Unit Cost of the LNG Scheme - Case (III)
1
Ge
nera
l In
form
ati
on
Ca
se:
Gas D
em
and
Scena
rio
Low
To
tal In
ve
stm
ent
in T
EU
R75
,705
0.7
414
71
7
Dis
cou
nt
Rate
6.5
%
Lifetim
e in
a30
Co
nstr
uctio
n P
erio
d in a
3
Sta
rt o
f O
pera
tion
20
11
2
Ca
sh
Flo
w
Ite
mY
ear
>>
n-3
n-2
n-1
15
10
15
20
25
30
Inve
stm
ent
Co
st
T E
UR
/a
26,4
97
26,4
97
22
,712
00
00
00
0
Fix
ed O
PE
XT
EU
R /
a0
00
2,1
90
2,1
90
2,1
90
2,1
90
2,1
90
2,1
90
2,1
90
Va
riab
le O
PE
XT
EU
R /
a0
00
55
955
955
955
955
955
955
9
Fu
el G
as S
up
plie
dt/
a0
00
12
0,8
90
122,2
58
122,2
58
116
,145
116
,145
116,1
45
116
,145
3
Pre
sen
t V
alu
e
Ca
pita
l T
EU
R /
a8
6,2
48
OP
EX
T E
UR
/a
35,8
98
Fu
el G
as S
up
plie
dt/
a1,5
59,3
63
4
Dyn
am
ic U
nit
Co
st
DU
C -
Ga
s S
up
ply
EU
R /
t78.3
EU
R /
1000
m³
58.5
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4 Techno-economic Specification of CNG Infrastructure
Compressed Natural Gas (CNG) is not yet publicly traded in any sizeable from or shape, this is
due to the lack of available infrastructure for CNG. Some countries have introduced miniature
CNG pilot projects for CNG powered vehicles such as busses or trucks. However, CNG has still
no sizeable market penetration that would allow the development of a commercial model for a
large scale CNG supply to Malta. There are no CNG vessels that are currently operating to
supply demand centres. Therefore CNG will not be considered in the further analysis. However,
typical future applications for CNG would be the supply of small Islands or small remote areas
that have no indigenous gas production or gas pipeline connection to supply gas.
However instead a CNG supply scheme a LNG regasification vessel could be an alternative to
the onshore LNG terminal or the sub sea gas pipeline from Sicily.
4.1 Technical Description of a LNG Regas Vessel
The only feasibly alternative to a LNG import using a conventional LNG Import and rega-
sification terminal is ship based re-gasification vessels developed by Exmar i.e. Energy Bridge.
A regasification vessel is capable of three different modes of cargo transfer (i) off-shore transfer
of gas via the STL Buoy; (ii) dock-side transfer via the high pressure gas manifold or (iii) LNG
transfer dockside into tanks or across dock ship to ship .
A typical re-gas vessel carries about 138 000 m3 LNG which converts to approximately 2.8 bcf
Gas or ~80 Mio m3 natural gas
Discharge pressure is up to 100 bars at a temperature of 4-5 deg. °C. Capacities of existing re-
gas fleet:
Capacity in Off-shore Mode is 14,150,000 m3/d using sea-water
(Unloading ~5.6 days);
Capacity in Dock-side Mode is 12,750,000 m3/d without sea-water
(Unloading ~6.2 days);
The turn-down ratio for Regas vessels is quite high and can be as low
as 2,830,000 m3/d.
The requirements for the Base Gas Demand Scenario are:
Average daily send-out is about 114,500 m3/h or 2,750,000 m3/d this means that the Regas
vessel will take about 30 days to empty its cargo volume of 80;000,000 m3 natural gas. In total
Malta would require 10 Regas shipments per year.
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The maximum hourly sent-out is about 165,000 m3/h which is well within the range of the Regas
vessel. The installation cost for the off-shore solution is about 32 Mio EUR not including the
onshore interconnection pipeline. Please note that for continuous supply (i.e. base load termi-
nal) a second STL Buoy has to be installed.
The dock-side solution requires the use of a jetty. This technology is only about 2 years old and
only about 15 LNG cargos have been delivered using Regas vessels. So far no technical
problems have been encountered but it is premature to declare Regasification vessel a proven
technology without risk!
Below is a schematic drawing showing a typical Regas-vessel.
Figure 4-1: Schematic Overview of a Regas-Vessel
High Pressure Pumps
And Vaporisers
Reinforced
LNG
Storage Tanks
Energy Bridge™
Regasification Vessel
Traction
Winch
Buoy
Compartment
Oversized
Boiler
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It should be noted that there is no prevailing business Model to charter LNG Regas vessels. So
far a “Fee for Service” approach has been used, but there is little to commercial history. The
“Fee for Service” Schedule Rates are not published and most likely require extensive case by
case negotiations.
The LNG Regasification vessels were primarily developed (i) to have an alternative LNG deli-
very method in areas where conventional LNG Regas terminal can not be built due to environ-
mental and general permitting concerns for a regasification terminal and (ii) where the gas
demand is either very small (< 2 bcm/a) or only spot delivery of LNG is required.
However, since Malta has the possibility to build a LNG terminal onshore it is not recommended
to further pursue the Regas vessel as an alternative delivery method.
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5 Dynamic Unit Cost Analysis for Gas Supply Alternatives
In order to provide a transparent and methodologically sound indicator to compare the different
gas supply options, the dynamic unit cost (DUC) calculation was carried out for each technically
feasible option. The dynamic unit cost approach allows to consider the full supply costs taking
into consideration its specific cost structure in terms of investment breakdown and expenditure
schedule, and to condense this case-specific and therefore heterogeneous information into one
homogeneous and meaningful cost information.
This chapter provides the comparison of the DUC calculations presented in the previous sec-
tions. Under consideration of all gas demand scenario below Table 5-1 provides the total fuel
Item Unit
EUR/t
EUR/t
Total EUR/t
Item Unit
EUR/t
EUR/t
Total EUR/t
Item Unit
EUR/t
EUR/t
Total EUR/t
Dynamic Unit Cost
of Fuel Supply78.3 96.4
258.3 299.0
Projected Market
Fuel Price (2011)180.0 202.6
203.7 228.5
LNG Scheme
Low Gas Demand
Pipeline Scheme
Low Gas Demand
Projected Market
Fuel Price (2011)180.0 202.6
Dynamic Unit Cost
of Fuel Supply23.8 25.9
LNG Scheme
High Gas Demand
Pipeline Scheme
High Gas Demand
202.6
26.8
LNG Scheme
Base Gas Demand
Pipeline Scheme
Base Gas Demand
180.0
204.4 229.4
Dynamic Unit Cost
of Fuel Supply
Projected Market
Fuel Price (2011)
24.4
Table 5-1: Comparison of Fuel Supply Cost – Gas Supply Alternatives
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110.0
130.0
150.0
170.0
190.0
210.0
230.0
250.0
270.0
2010 2015 2020 2025 2030
Year
Gas v
ia L
NG
Co
nvers
ion
EU
R/t
110.0
130.0
150.0
170.0
190.0
210.0
230.0
250.0
270.0
2010 2015 2020 2025 2030
Year
Natu
ral
Gas v
ia P
ipeli
ne E
UR
/t
Figure 5-1: Comparison of Fuel Gas Prices of Supply Alternatives investigated
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costs in EUR per tonne including the costs of the supply and the market price (for the first pos-
sible year of supply scheme’s operation). The approach for the price projection is described
already in the Section 3.2.1 of this report.
Exemplarily the results within the frame of the base gas demand are discussed here. The LNG
scheme is the gas supply alternative which contributes the lowest fuel cost. The costs of some
204.4 EUR/t are 11% lower than the cost of the pipeline scheme. An overview of the costs’
development up to the year 2030 is provided in the above charts. The LNG alternative leads to
221.0 EUR/t in 2030 whereas the pipeline alternative reaches 248.2 EUR/t.
In all comparative assessments, the LNG scheme is that one with the lowest costs. Therefore it
is recommended as the least cost gas supply option and the related cost are used as input
figures within the techno-economic assessment of the gas-based local power generation op-
tions.
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6 Techno-economic Specification of Gas-Based Generation Options
This chapter of the report is devoted to technical and economic aspects of gas-based
generation options identified and considered as potential candidates for the expansion of the
Maltese power generation system. Within the frame of the identification process LI’s experts
considered two basic types of projects.
These are:
the construction of new generation units; and
the refurbishment of existing units.
The investigated supply options are summarised in the following Table 6-1. In the manner intro-
duced for the existing power generation units (see Chapter 1 of this report) each supply option is
labelled by an identification code which will be used in the following sections and later be
applied within the computer-aided system simulation (Work Package III).
Item
Capacity
Range Description
Identi-
fication
Option 1 ~ 100 MW New Gas-fired combined cycle gas turbines
in 2 GT and 1 ST configuration CCGT 2+1
Option 2 ~ 100 MW New Gas-fired combined cycle gas turbines
in 1 GT and 1 ST configuration CCGT 1+1
Option 3 + 120 MW Repowering of an (existing) condensing steam turbine to
combined cycle in 2 GT + 1 ST configuration 2+1 ST R
Option 4 + 40 MW Repowering of (existing) gas turbines to combined cycle
in 2 GT + 1 ST configuration 2+1 GT R
Table 6-1: General Data – New Gas-Based Generation Options
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6.1 Technical Description of Gas-Based Generation Option 1 (CCGT 2+1)
6.1.1 Basic Design
Due to their high efficiency combined cycle gas turbine (CCGT) stations are the dominant power
generation technology in recent years in Europe (see also WP I Report). The plants can be
operated on natural gas or oil (Gasoil, Light Crude Oil). The heat of the exhaust gas from the
gas turbine is used to make steam to generate additional electricity via a steam turbine; this last
step thus enhances the efficiency of electricity generation.
For the first supply option a combined cycle power plant consisting of two gas turbines, two heat
recovery steam generators (HRSG) and one condensing steam turbine was defined. At an
international level three important manufacturers offer such power plants (i) General Electrics
(GE) Power Systems; (ii) Alstom; and (iii) Siemens. In the following the major technical and
operational characteristics of this supply option are presented. Maltese local conditions and
provided fuel specifications have been considered. The performance data of this supply option
as presented in the following is based on the gas turbine (GT) of type GE 6581B and dual
pressure HRSG without duct burner firing.
Plant Characteristics Unit Value
Plant Type CCGT 2+1
Set Size (nominal) MW 128.0
Partial Load 100% 85% 70% 50% 30% 20%
Set Capacity (gross) MW 128.0 109.3 89.6 63.6 38.4 25.1
Set Capacity (net) MW 125.5 106.9 87.0 62.0 36.9 24.8
Auxiliary Power MW 2.5 2.4 2.6 1.6 1.4 0.3
Self Consumption % 1.9% 2.2% 2.9% 2.5% 3.8% 1.2%
Turbines in Operation 2GT+1ST 2GT+1ST 2GT+1ST 1GT+1ST 1GT+1ST 1GT
Partial Load 100% 85% 70% 50% 30% 20%
Net Heat Rate kJ/kWh 7,441 7,647 7,963 7,528 8,478 13,974
Planned Outage d/a 20
Forced Outage %/a 3%
Max Availability %/a 91.5%
Table 6-2: Technical Data – Gas-Based Generation Option 1
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Another possible gas turbine types of similar size are for example the Siemens SGT-800F.
The gas turbines are designed with a dual fuel combustion system using LNG (gaseous) as
primary fuel. The design capacity of the gas turbines amounts to 41.1 MW (Net) each. The de-
sign capacity of the steam turbine is 43.2 MW (Net). For the cooling system an open loop water
cooling with a seawater inlet temperature of 20 °C and an allowable cooling water temperature
rise of 8 K is assumed.
The heat recovery steam generators (HRSG) are equipped with a bypass stack for simple cycle
operation of the gas turbines in order to increase the operational flexibility of the plant. Most
important for the steam cycle efficiency is the HRSG configuration and design. Both HRSG
produce in total 35.4 kg/s high pressure steam with 67.7 bar and 529 °C and an intermediate
pressure steam of 5.92 kg/s with 8.3 bar and 258 °C.
Table 6-2 provides the general technical parameters of the supply option (design conditions). A
partial load range between 100% (full load) and 20% is selected regarding the provision of the
operational characteristics, which can be summarized as follows:
The plant’s self consumption (auxiliary power) drops from 2.5 MW to 0.3 MW in absolute
terms. Related to the plants output the value increases from 1.9% (2 GT + 1 ST opera-
tion) to 3.8% (1 GT + 1 ST operation) and decreases then to some 1.2% (1 GT opera-
tion);
The plant’s net heat rate increases from 7,441 kJ/kWh to nearly 14,000 kJ/kWh over the
entire range of partial load. This is equal to a net efficiency decrease from 48.4% to
25.8% only.
Assuming outage characteristics of an average of 20 days a year for the units’ maintenance and
a 3% forced outage, the maximum availability of the plant is expected to amount 91.5% over a
year. The net and gross heat rates of the gas based supply option 1 are shown in the following
figure over the entire load range (calculated on fuel’s NCV). The results of GT Pro calculations
are summarized within the heat and mass balance diagrams in the Figures 6-2 and 6-3. The
calculations are based on the maximum load of the plant during summer and winter conditions.
The comparison of the summer and winter parameters brings out the following results:
The plant’s net capacity during summer amounts to only 88% (111.7 MW) compared to
the net capacity during the winter period by some 127.1 MW. Our analysis of the existing
system already brought out similar capacity levels in relation to the temperature
fluctuations in Malta (see work package I);
The plants’ net heat rate decreases from 7,560 kJ/kWh during summer to 7,414 kJ/kWh
during winter. This is equal to a net efficiency increase from 47.6% (summer) to 48.6%
(winter).
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-4
Figure 6-1: Gross and Net Heat Rates – Gas-Based Generation Option 1
He
at
Ra
tes (
kJ
/kW
h)
of
Su
pp
ly O
pti
on
1 -
2+
1 C
CG
T N
G f
ire
d
0
2,0
00
4,0
00
6,0
00
8,0
00
10
,00
0
12
,00
0
14
,00
0
16
,00
0
18
,00
0
020
,000
40
,000
60
,000
80
,000
10
0,0
00
120
,000
140
,000
Lo
ad
(kW
)
Heat Rate (kJ/kWh)
2+
1 g
ross H
R
2+
1 n
et
HR
1+
1 g
ross H
R
1+
1 n
et
HR
1+
0 g
ross H
R
1+
0 n
et
HR
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-5
GT
MA
ST
ER
17
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ar],
T[C
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7
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GE
658
1B
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T
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47
1.6
m
1 p
36
T
47
1.6
m
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G 8
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1 m
20 T
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V= 1
17
29
4 k
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11.2
8 p
376
T 1
0.8
3 p
11
32 T
480
.3 m
1.0
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567 T
960.7
M
72.7
3 %
N2
13.3
7 %
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CO
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5 %
H2O
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7
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1
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36 m
^3/k
g3
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.2 m
^3/s
426
45
kW
0.0
385
M
FW
0.1
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2 p
46 T
148
.8 M
46 T
2.3
23
p
11
6 T
15
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M
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E
46
T 1
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M
116 T
2.3
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12
5 T
152.9 M
9.1
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p
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1 T
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M
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2
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59 p
176 T
23.9
M
IPB
8.9
93 p
22
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21
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1
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73.7
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HP
E2
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71.8
2 p
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HP
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5 T
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1.5
0 M
67
.73
p 5
29 T
12
7.5
M
70.09 p 545 T
1.5
8 M
3.0
8 M
21.3
M
8.325 p 258 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-2
: H
eat
an
d M
ass B
ala
nce –
Gas-B
ased
Ge
ne
rati
on
Op
tio
n 1
(S
um
me
r C
on
dit
ion
s)
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-6
GT
MA
ST
ER
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100%
load a
t w
inte
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Pow
er 127120 k
WLH
V H
eat R
ate
741
4 k
J/k
Wh
p[b
ar],
T[C
], M
[t/h
], S
team
Pro
pertie
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PW
S-IF97
1X
GE
6581B
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41563 k
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1.0
1 p
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45 %
RH
523 m
1 p
13 T
523 m
LN
G 9
.789 m
20 T
LH
V= 1
30906 k
Wth
12.4
4 p
358 T
11.9
4 p
1136 T
532.8
m
1.0
4 p
551 T
1065.5
M
75.3
%N
2 1
3.9
5 %
O2
3.3
78 %
CO
2 6
.469 %
H2O
0.9
067 %
Ar
549 T
1065.5
M
2.2
99 m
^3/k
g680.4
m^3
/s
549
482
482
482
471
305
303
274
271
242
242
193
163
163
117 T
1065.5
M
1.1
2 m
^3/k
g331.6
m^3
/s
46507 k
W
0.0
399 M
FW
0.0
544 p
34 T
153.9
M
34 T
2.3
23 p
114 T
155.5
M
LT
E
34 T
155.5
M
114 T
2.3
23 p
125 T
158.8 M
9.5
65 p
174 T
158.8
M
IPE
2
9.5
65 p
178 T
26.9
2 M
IPB
9.3
72 p
229 T
23.6
1 M
IPS
1
9.1
98 p
261 T
23.6
1 M
IPS
2
3.303 M
75.5
p
233 T
131.6
M
HP
E2
74.0
8 p
285 T
131.6
M
HP
E3
74.0
8 p
290 T
130.3
M
HP
B1
73.3
6 p
309 T
130.3
M
HP
S0
71.5
7 p
530 T
130.3
M
HP
S3
69.1
5 p
528 T
130.3
M
71.57 p 530 T
23.6
1 M
8.612 p 259 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-3
: H
eat
an
d M
ass B
ala
nce –
Gas-B
as
ed
Gen
era
tio
n O
pti
on
1 (
Win
ter
Co
nd
itio
ns)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-7
6.1.2 Location
Regarding the possible erection of new power generation units, in general it was set focus to the
Delimara Power Station site.
Potential sites for additional power generating facilities (such as CCGTs) are already reserved
for the Delimara Power Station site. The geometric properties of supply option 1 would be com-
parable to those of the already existing combined cycle plant. This one and the potential sites
for the new CCGT are illustrated in the modal and map provided in the following figure.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-8
Figure 6-4: Potential Location of Gas-Based Generation Option 1
6.1.3 Air Pollution Emissions
In the following tables the environmental impact due to potential air pollution emissions is
considered. Based on the unit’s capacity and thermodynamic parameters, like e.g. specific
energy input and combustion temperatures as well as fuel air ratio lambda, the unit’s behaviour
regarding all possible operation modes was simulated. As already known both from physical
theory and operational experience, the partial load behaviour in terms of efficiency and fuel
consumption cannot be compared with full load operation mode. According to CO2 and SO2
emissions, the specific values for considered generation technologies can be reviewed over
several plant’s load characteristics. Moreover NOx conditions and influence parameters are sho-
wn as well as the specific emissions. Generally speaking, the NOx emissions are declining while
the unit operates in partial load, because of being significantly addicted to the combustion
temperature which is also declining due to thermo-dynamic simulations.
Calculations were carried out to demonstrate that the supply option 1 complies with the EU envi-
ronmental directives and with all the relevant aspects of the Maltese Legislation Act YY of 2001
(“Environmental Protection Act) as well as with the associated legal notices. With regard to the
European Large Combustion Plant Directive (LCPD 2001/80/EC) EU Member States may
choose, by 1 January 2008, to either comply with the Emission Limit Values (ELV) set down in
the LCPD or to produce and implement a national emission reduction plan. National plans
should reduce the total annual emissions of SO2, NOx and particulate matter to the levels that
would have been achieved by applying the ELVs set out in the LCPD to existing plants in
operation in the year 2000, on the basis of each plant’s operational performance averaged over
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-9
the last five years of operation up to and including 2000. Furthermore, national plans should
specify the measures that will be implemented to ensure that this is achieved.
Malta’s National Programme under the Emissions Ceilings Directive was prepared by the Malta
Environmental and Planning Authority (MEPA) and published in December 2006. The program-
me describes clearly the current state and provides detailed targets regarding the future
development of Nitrogen Oxides and Sulphur Dioxide emissions of the power generating sector
in Malta.
Impacts on the existing generation system were already described in the report of the work
package I (in particular the limited operation hours of the Marsa Power Station). Regarding to
the operation of new power plants the National Programme under the Emissions Ceilings
Directive provides the following emission factors (EF):
2010: Unabated EF for NOx emissions of 500 t/PJ; Abated EF for NOx emissions
of 155 t/PJ (assuming a removal efficiency of 69%);
2010: Unabated EF for SO2 emissions of 234 t/PJ; Abated EF for SO2 emissions
of 57 t/PJ (assuming a removal efficiency of 80%);
2020: Unabated EF for NOx emissions of 500 t/PJ; Abated EF for NOx emissions
of 155 t/PJ (assuming a removal efficiency of 69%);
2020: Unabated EF for SO2 emissions of 234 t/PJ; Abated EF for SO2 emissions
of 57 t/PJ (assuming a removal efficiency of 80%).
The above targets are related to the energy input before the conversion to the plant’s electricity
output (sent-out). Transforming the values to the plant’s sent-out related emission limits the
following ELV for new power generating facilities have to be considered:
A maximum of 1.2 g/kWh regarding the emissions of NOx;
A maximum of 2.2 g/kWh regarding the emissions of SO2.
The Greenhouse Gas Emission Trading Scheme (EU Directive 2003/87/EC) was transposed in
the L.N. 140/2005 of the Maltese Legislations and sets the limits on Greenhouse Gas Emissions
(mainly CO2). Regarding the plant’s sent-out the EF amounts to:
A maximum of 630 g/kWh regarding the emissions of Greenhouse Gases.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-10
General Information
# Item 1
1 Plant Name Natural Gas Based Supply Option 1
2 Plant Type Combined Cycle Gas Turbine
3 Unit CCGT 2+1 NG fired
4 State Option
5 Unit_Ident
6 Comments
No Comments
Technical & Operational Data for Emissions (continued)
# Item Dim 1
7 Nominal Capacity MW 127.9
8 Max Capacity Sent-Out (Operation) MW 125.5
9 Min Capacity Sent-Out (Operation) MW 31.1
10 Heat Rate* Coeff A (2+1) - 3,010
11 Heat Rate* Coeff B (2+1) - -6,795
12 Heat Rate* Coeff C (2+1) - 11,238
10a Heat Rate* Coeff A (1+1) 15,328
11a Heat Rate* Coeff B (1+1) -16,885
12a Heat Rate* Coeff C (1+1) 12,144
13 Combustion Temp Coeff A - -742
14 Combustion Temp Coeff B - 1,579
15 Combustion Temp Coeff C - 485
16 Air Rate Lambda Case1 1.0 - 1.09
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ /
kW
h
700
2700
4700
6700
8700
10700
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[co
mb
. te
mp
.]
Table 6-3: Specifications of D_CC1NGo (1/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-11
NOx Emissions
# Item 1
17 Thermal Nox Coeff. A 1E-21 Fuel Nox Coeff. A NA
18 Thermal Nox Coeff. B 7.72 Fuel Nox Coeff. B NA
19 Fuel Nox Coeff. C NA
20 Thermal NOx Emissions over load (RAW)
21 Specific NOx Emissions in g/kWh Absolute NOx Emissions in tons
Fuel Specifications
22 Initial Primary Fuel Rich gas Natural Gas % of Carbon 75.00%
23 Net Calorific Value kJ/kg 48,156 % of Nitrogen 0.00%
24 Required Fuel at 100% load kg 19,795 % of Sulphur 0.00%
25 Required Combustion Air m³ 9.89 % of Nox Reduc. 50.00%
26 Resulting Exhaust Gas m³ 10.34 % of SO2 Reduc. 0.00%
Fuel NOx Emissions over load (RAW)
Fuel Composition
(Emission Relevant)
Potential Emission Reduction
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
1
mg/m³
2242
6376
64
107
158
211
255
7
0
50
100
150
200
250
300
13 26 38 51 64 77 90 102 115 128
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
Table 6-3: Specifications of D_CC1NGo (2/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-12
CO2 and SOx Emissions
# Item 1
27 Fuel needed at 100% load t 19.79
28 Density of Fuel kg / m³ 0.77
29 CO2 emission at 100% load t 53.38
30 Specific CO2 Emissions in g/kWh Absolute CO2 Emissions in t
31 Specific SOx Emissions in g/kWh Absolute SOx Emissions in tons
Exhaust Gas development in m³ due to Gross Performance
32
29,12351,499
69,655
103,402
135,795152,889
169,723186,792
204,592
86,115
0
50,000
100,000
150,000
200,000
250,000
1
m³ Exhaust Gas
525474
439 422462 446 433 423 417
594
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
7.613.4
18.222.5
27.0
35.439.9
44.348.7
53.4
0
10
20
30
40
50
60
13 26 38 51 64 77 90 102 115 128
[t CO2]
[MW]
n/a n/a
Table 6-3: Specifications of D_CC1NGo (3/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-13
The air pollution emissions of the investigated supply option:
do not exceed the limit value for NOx emissions;
do not exceed the limit value for SO2 emissions. Natural gas does not cause such
emissions at all;
are 54% below the current Green House Gas emissions (typical unit operation assumed)
and do not exceed the limit value for CO2 emissions.
Finally, Figure 6-5 provides a comparison of the calculated GHG emissions of the supply option
and the today dominating technology in the Maltese power generation system.
871
420
921
-
100
200
300
400
500
600
700
800
900
1,000
Business as Usual
(all STs)
Business as Usual
(DPS ST)
Supply Option
Sp
ec
ific
Em
iss
ion
s g
CO
2/k
Wh
.
Figure 6-5: Comparison of Greenhouse Gas Emissions - Gas-Based Generation Option 1
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-14
6.2 Economic Description of Gas-Based Generation Option 1 (CCGT 2+1)
6.2.1 Investment Costs of Major Components
The payment plan for a power plant project such as for the investigated supply options is closely
linked to the foreseen implementation schedule, in the way that there is normally a:
down payment of 10 – 20% of the contract value, covered by a down payment security, after
the award of contract to the Contractor;
a final payment of about 5% at the end of the warranty period; and a series of intermediate
payments linked to major events of work progress, the so-called “Milestones”, as there are:
o Mobilisation and site preparation;
o Civil works design;
o Civil construction works, incl. administration building;
o Architectural and civil finishing works;
o Design, manufacturing and transport of mechanical, electrical and Instrumentation & Control (I&C) equipment;
o Design, manufacturing and transport of the gas turbine generator(s);
o Erection of the gas turbine with auxiliaries, incl. commissioning and testing;
o Erection of heat recovery steam generator;
o Erection and commissioning of steam turbine generator;
o Erection and piping and components of water steam;
o Erection of cooling water system, mechanical, electrical and I&C equipment;
o Erection and commissioning of mechanical auxiliary equipment;
o Erection of electrical equipment;
o Erection of distributed control system (DCS) and other I&C equipment;
o Commissioning of the combined cycle;
o Reliability test run;
o Taking over by Owner.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-15
# Item
1
2
3
4
5
6
7
8
9
10
11
Total: 89,775
Heat Recovery Boiler
Cooling Facility/Cooling System
10,342
14,125
750
Gas Turbine Package incl. Generator 24,700
Steam Turbine Package incl. Generator
Investment Costs
in T EUR
Balance of Plant 6,095
Electrical Equipment 7,189
I&C Equipment 1,354
Civil/Buildings incl. On-Site Transportation 8,905
Engineering 3,470
Plant Startup 644
Contractor's Soft Costs 12,177
Table 6-4: Investment Costs of Gas-Based Generation Option 1
The above table provides the supply option’s investment cost in total and for each major com-
ponent. In total, the projects investment cost amounts to 89.8 Mio Euro (10% contingencies in-
cluded). The specific investment cost is 715 EUR/kW.
Figure 6-6 illustrates the investment break down. The dominating cost proportions are (i) the gas
turbine package; (ii) the heat recovery boiler; (iii) soft costs of the contractor and (iv) the steam
turbine package.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-16
Year n-3 n-2 n-1 n
Disbursement in % 50% 30% 20% Start Year
Table 6-5: Disbursement Schedule of Gas-Based Generation Option 1
The investment’s disbursement was derived under consideration of the major project steps
which were explained at the beginning of this section (see Table 6-5; n is equal to the first year
of plants’ operation).
28%12%
16%
1%
7%
8%
2% 10%4%
1%
14%
Gas Turbine Package incl. Generator and Air
inlet cooling/heating if applicable
Steam Turbine Package incl. Generator
Heat Recovery Boiler
Cooling Facility/Cooling System
Balance of Plant
Electrical Equipment
I&C Equipment
Civil/Buildings incl. On-Site Transportation
Engineering
Plant Startup
Contractor's Soft Costs
Figure 6-6: Investment Cost Break Down of Gas-Based Generation Option 1
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-17
6.2.2 Operational and Maintenance Costs
Gas Supply Costs Estimation
As the result of the assessments in the chapters 1 to 5 the development of the costs of the
supply of gas to the power plant is presented in the below Table. The year 2011 is selected as
the first possible year of the plant’s operation. This assumption takes into account the project’s
schedule given in the previous section.
Item Unit 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
EUR/t 204.4 197.7 191.0 191.0 191.0 191.0 194.4 197.7 201.0 201.0
Item Unit 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
EUR/t 204.4 207.7 211.0 214.4 216.0 217.7 217.7 219.4 219.4 221.0
Fuel Supply Costs
(via LNG conversion)
Fuel Supply Costs
(via LNG conversion)
Table 6-6: Gas Supply Costs
Fixed O&M Costs
Fixed costs of operation and maintenance include expenses for staff salaries; insurance, fees
and other cost which remain constant irrespective of the actual quantum of the plant’s electrical
energy sent-out.
The personnel costs are calculated by the estimated number of required staff (25 employees)
and the average annual salary (30 T EUR/a). Based on experiences in similar assignments the
proportion of the remaining fixed operation and maintenance costs is 2.5% of the capital costs.
.
# Item
1
2
Total Annual Fixed OPEX: 2,994
Costs in T EUR/a
Personnel Costs 750
Insurance, Fees and Others 2,244
Table 6-7: Estimate of Annual Fixed OPEX
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-18
Variable O&M Costs
Variable costs of operation and maintenance include the cost of fuel and costs for e.g.
lubricating oil and chemicals which are consumed in proportion to the actual amount of the
plant’s electrical energy sent-out. The dominating proportion of the variable OPEX is the cost of
fuel, which depends on the fuel supply cost and the amount of fuel utilized. The latter item again
depends on the plant’s efficiency and further on the plant’s operation mode (e.g. full load or
partial load; number of turbines in operation). In the first section of this chapter the plant’s
performance parameters are described in detail. The following economic analysis considers
individual operation modes and the related specific fuel input. Based on our experience in
similar assignment the value of the remaining variable OPEX is estimated at 1.6 EUR/MWh.
6.2.3 Dynamic Unit Cost Assessment for Option 1
The economic analysis involves the derivation of the dynamic unit cost (DUC) for the proposed
local generation option. The (economic) dynamic unit cost is derived by dividing the present
value of the project costs at economic prices, by the present value of the quantity of output (the
plant’s net generation). In this case the DUC represents the specific power generation cost over
the project’s life cycle. Costs in this context are in reference to the investment and the variable
and fixed operation & maintenance costs. Duties, taxes, etc. are not taken into consideration for
the derivation of the economic dynamic unit cost. A discount rate of 6.5% is applied. The period
under consideration is equal to the estimated project’s economic lifetime.
The following chart provides the calculation of the dynamic unit cost of the gas-based option 1.
As far as the actual future operation of the plant is not known (this depends mainly on the most
economic dispatch of the unit as one component of the entire power generation system; see
Work Package III) we provide cost figures over the entire load range. Exemplarily the calculation
in the chart is based on an 85% load assumption. Nevertheless, the results are shown for
different operation modes from full load to partial load. The DUC trends are shown in Figure 6-7.
Regarding the expected annual net generation the option’s maximum availability of 91.5% is
considered in the 100% full load case.
In the selected 85% load case the DUC of the gas-based local generation option 1 amounts to
46.1 EUR/MWh. Only slight fluctuations of the DUC are observed within the plant’s base load
operation. In full load operation the DUC are 4% lower than the reference value. At 70% load
level the DUC are 9% higher than the reference value. In intermediate and peak load operation
the cost figures increase highly. At 50%-load an increase of 17% and at 20%-load an increase
of 141% is registered in comparison to the reference value.
The plant’s maximum annual net generation amounts to 1,006 GWh/a (at maximum availability
and full load).
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-19
Table 6-8: Dynamic Unit Cost of the Gas-based Option 1
1
G
en
era
l In
form
ati
on
Loca
l Gene
ratio
n O
ptio
n 1
(C
CG
T 2
+1)
p
1.1
Tech
nic
al
1.2
Eco
no
mic
s
Pla
nt
Typ
e -
-C
CG
T 2
+1
Set
Siz
e (
nom
inal)
MW
128.0
Part
ial L
oad
100%
85%
70%
50%
30%
20%
To
tal I
nve
stm
en
tT
EU
R89,7
75
Set
Capaci
ty (
gro
ss)
MW
128.0
109.3
89.6
63.6
38.4
25.1
Dis
count
Rate
%6.5
%
Set
Capaci
ty (
net)
MW
125.5
106.9
87.0
62.0
36.9
24.8
Life
time
a30
Auxi
liary
Pow
er
MW
2.5
2.4
2.6
1.6
1.4
0.3
Const
ruct
ion
Pe
riod
a3
Self
Consu
mptio
n%
1.9
%2.2
%2.9
%2.5
%3.8
%1.2
%
Turb
ines
in O
pera
tion
--
2G
T+
1S
T2G
T+
1S
T2G
T+
1S
T1G
T+
1S
T
1G
T+
1S
T1G
TF
ixed O
PE
X
T E
UR
/a2,9
94
100%
85%
70%
50%
30%
20%
Variable
OP
EX
*E
UR
/MW
h1.6
Net
Heat
Ra
te
kJ/k
Wh
7,4
41
7,6
47
7,9
63
7,5
28
8,4
78
13,9
74
Fu
el T
ype
--
Reg
as
LN
G
Pla
nned O
uta
ge
d/a
20
Net
Calo
rific
Valu
ekJ
/kg
48,1
50
Forc
ed O
uta
ge
%/a
3%
Max
Ava
ilabili
ty%
/a91.5
%*
oth
er
tha
n F
ue
l C
osts
2
Cash
Flo
wO
pe
ratio
n a
t 8
5%
Load
Item
Year
>>
n-3
n-2
n-1
12
34
510
20
30
Inve
stm
ent
Co
stT
EU
R/a
44
,888
26,9
33
17,9
55
00
00
00
00
Fix
ed O
PE
XT
EU
R/a
00
02,9
94
2,9
94
2,9
94
2,9
94
2,9
94
2,9
94
2,9
94
2,9
94
Variable
OP
EX
T E
UR
/a0
00
31
,748
30,7
61
29,7
74
29,7
74
29,7
74
31,2
54
34,2
15
36
,787
Fuel S
up
ply
Cost
s (s
peci
fic)
EU
R/t
00
0204
198
191
191
19
1201
221
238
Fuel S
up
ply
Cost
s (a
bso
lute
)T
EU
R/a
00
030
,256
29,2
70
28,2
83
28,2
83
28,2
83
29,7
63
32,7
23
35
,296
Fuel I
nput
t/a
00
0148,0
45
148,0
45
148,0
45
148
,045
148,0
45
148,0
45
148
,045
148,0
45
Net
Genera
tion
GW
h/a
00
0932
932
932
932
93
2932
932
932
3
Pre
sen
t V
alu
e
Capita
l T
EU
R1
03,8
91
OP
EX
T E
UR
457,8
10
Net
Genera
tion
GW
h12,1
73
4
Dyn
am
ic U
nit
Co
st
Part
ial Load
100%
85%
70%
50%
30%
20%
125
5106
787
962
837
725
1
DU
C -
Po
wer
Gen
era
tio
nE
UR
/MW
h4
4.4
46.1
50.1
53.9
71.8
110
.9
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-20
0
20
40
60
80
100
120
140
- 20.0 40.0 60.0 80.0 100.0 120.0
Plant's Operation - Load (Net) in MW
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
0
20
40
60
80
100
120
140
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Plant's Operation as Percentage of Load
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
-
200
400
600
800
1,000
1,200
1,400
Pla
nt's N
et
Gen
era
tio
n i
n G
Wh
/a
Figure 6-7: Dynamic Unit Cost over Plant’s Load - Gas-Based Option 1
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-21
6.3 Technical Description of Gas-Based Generation Option 2 (CCGT 1+1)
6.3.1 Basic Design
This power plant is a combined cycle power plant consisting of one gas turbine, one HRSG and
one condensing steam turbine as single shaft design. On an international level the following two
important manufacturers can deliver such power plants: (i) General Electrics (GE) Power Sys-
tems; (ii) Siemens.
The gas turbine is designed with a dual fuel combustion system using LNG (gaseous) as
primary fuel and diesel as secondary fuel. Water injection for NOx reduction when burning diesel
may be considered in order to meet the allowed NOx emission standard. Because of the single
shaft configuration there is a steam turbine clutch installation assumed. A single cycle operation
of the gas turbine is thereby possible and thus the operational flexibility of the plant is increased.
The heat recovery steam generator (HRSG) is equipped with a bypass stack. The design
capacity of the gas turbine amounts to 75.2 MW (Net). The design capacity of the steam turbine
is 37.1 MW (Net).
Plant Characteristics Unit Value
Plant Type CCGT 1+1
Set Size (nominal) MW 114.6
Partial Load 100% 85% 70% 50% 40% 25%
Set Capacity (gross) MW 114.6 96.8 78.3 58.3 46.0 30.8
Set Capacity (net) MW 112.3 94.6 76.2 56.3 45.4 30.3
Auxiliary Power MW 2.4 2.2 2.1 1.9 0.6 0.5
Self Consumption % 2.1% 2.3% 2.7% 3.3% 1.3% 1.6%
Turbines in Operation 1GT+1ST 1GT+1ST 1GT+1ST 1GT+1ST 1GT 1GT
Partial Load 100% 85% 70% 50% 40% 25%
Net Heat Rate kJ/kWh 6,930 7,141 7,471 8,122 12,564 15,101
Planned Outage d/a 18
Forced Outage %/a 3%
Max Availability %/a 92.1%
Table 6-9: Technical Data – Gas-Based Generation Option 2
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-22
Maltese local conditions and provided fuel specifications have been considered for the evalu-
ation of the major operational parameters. The performance data of this supply option is based
on the gas turbine (GT) of type GE 6111FA and dual pressure HRSG without duct burner firing.
Another possible gas turbine type of similar size is for example the Siemens SGT-1000F but in
this case an upgraded GT (with higher turbine inlet temperature and exhaust gas mass flow) or
a HRSG with duct burner firing is needed.
The HRSG produces in this case 29.7 kg/s high pressure steam with 67.5 bar and 585 °C and
an intermediate pressure steam of 3.17 kg/s with 8.3 bar and 258 °C. The indoor located
condensing steam turbine has a capacity of 37 MW. For the cooling system an open loop water
cooling with a seawater inlet Temperature of 20 °C and a allowable cooling water temperature
rise of 8 K is assumed.
Table 6-9 provides the general technical parameters of the supply option (design conditions). A
partial load range between 100% (full load) and 25% is selected regarding the provision of the
operational characteristics, which can be summarized as follows:
The plant’s self consumption (auxiliary power) drops from 2.4 MW to 0.5 MW in absolute
terms. Related to the plants output the value increases from 2.1% to 3.3% (1 GT + 1 ST
operation) and decreases thereafter to for example 1.3% (1 GT operation);
The plant’s net heat rate increases from 6,930 kJ/kWh to more than 15,000 kJ/kWh over
the entire range of partial load. This is equal to a net efficiency decrease from 51.9% to
23.8% only.
Assuming outage characteristics of an average of 18 days a year for the units’ maintenance and
a 3% forced outage, the maximum availability of the plant is expected to amount 92.1% over an
entire year.
The net and gross heat rates of the gas based supply option 2 are shown in the following figure
over the entire load range (calculated on fuel’s NCV). The results of GT Pro calculations are
summarized within the heat and mass balance diagrams in the Figures 6-9 and 6-10. The
calculations are based on the maximum load of the plant during summer and winter conditions.
The comparison of the summer and winter parameters brings out the following results:
The plant’s net capacity during summer amounts to 86.1% (97.8 MW) compared to the
net capacity during the winter period by some 113.6 MW.
The plants’ net heat rate decreases from 7,113 kJ/kWh during summer to 6,903 kJ/kWh
during winter. This is equal to a net efficiency increase from 50.6% (summer) to 52.2%
(winter).
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-23
Figure 6-8: Gross and Net Heat Rates – Gas-Based Generation Option 2
Heat
Rate
s (
kJ/k
Wh
) o
f S
up
ply
Op
tio
n 2
- 1
+1 C
CG
T N
G f
ired
0
2,0
00
4,0
00
6,0
00
8,0
00
10,0
00
12,0
00
14,0
00
16,0
00
020,0
00
40,0
00
60,0
00
80,0
00
100,0
00
120,0
00
Lo
ad
(kW
)
Heat Rate (kJ/kWh)
1+
1 g
ross H
R
1+
1 n
et
HR
1+
0 g
ross H
R
1+
0 n
et
HR
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-24
GT
MA
ST
ER
17
.0.1
LI - W
. E
isenh
art
31
6 0
8-2
0-2
007
11:2
7:3
3
file
=T
:\2
6\0
40
0\2
60
442
_m
alt
a\0
6_
pro
ject_
res
ults
\GT
Pro
\Case
2 (1+
1) n
eu\C
CG
T 1
+1 N
G F
IRE
D 1
00%
loa
d s
um
me
r con
ditio
ns.g
tm
CC
GT
1+1
configura
tion N
G f
ired
100%
load
at su
mm
er c
ond
itio
ns
Net
Po
we
r 97
771
kW
LH
V H
eat R
ate
71
13
kJ
/kW
h
p[b
ar], T
[C],
M[t
/h],
Ste
am
Pro
pertie
s: IA
PW
S-IF
97
1X
GE
61
11F
A
629
65 k
W
1.0
1 p
36 T
70 %
RH
666
.8 m
1 p
36 T
666.8
m
LN
G 1
4.4
5 m
31
T 2
0 T
LH
V=
19
317
6 k
Wth
14
.02 p
39
7 T
13.3
2 p
131
8 T
68
1.2
m
1.0
4 p
629 T
681.2
M
72
.39 %
N2
12
.3 %
O2
3.8
37 %
CO
2 1
0.6
%H
2O
0.8
716 %
Ar
627
T 6
81
.2 M
2.5
68 m
^3/k
g48
5.9
m^3
/s
62
7
52
0
520
520
506
302
301
2
65
2
63
2
27
2
27
18
9
15
7
157
109
T 6
81
.2 M
1.1
14 m
^3/k
g21
0.8
m^3
/s
370
72 k
W
0.0
344 M
FW
0.1
03
2 p
46 T
118
.4 M
46 T
2.3
23
p
115
T
119
.6 M
LT
E
46 T
119
.6 M
115
T 2
.32
3 p
12
5 T
121.8 M
9.0
77 p
171 T
121.8
M
IPE
2
9.0
77 p
176 T
13.6
3 M
IPB
8.9
52 p
22
8 T
11
.41 M
IPS
1
8.7
83
p
260
T
11.4
1 M
IPS
2
2.225 M
73.4
5 p
229
T
104
.9 M
HP
E2
72.2
2 p
282
T
104
.9 M
HP
E3
72.2
2 p
288 T
103.9
M
HP
B1
71.7
1 p
309 T
103.9
M
HP
S0
69
.84 p
60
7 T
10
5.3
M
HP
S3
1.7
3 M
67.4
9 p
585 T
107 M
69.84 p 607 T
1.3
8 M
3.1
2 M
11.4
1 M
8.302 p 258 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-9
: H
eat
an
d M
ass B
ala
nce –
Gas-B
ased
Ge
ne
rati
on
Op
tio
n 2
(S
um
me
r C
on
dit
ion
s)
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-25
GT
MA
ST
ER
17.0
.1 L
I - W
. E
isenhart
316 0
8-2
0-2
007 1
1:2
7:5
7 file
=T
:\26\0
400\2
60442_m
alta\0
6_p
roje
ct_
results\G
TP
ro\C
ase 2
(1+1) ne
u\C
CG
T 1
+1 N
G F
IRE
D 1
00%
loa
d w
inte
r condit
ions.g
tm
CC
GT
1+1 c
onfigura
tion N
G fired
100%
load a
t w
inte
r conditio
ns
Net P
ow
er 113597 k
WLH
V H
eat R
ate
6903 k
J/k
Wh
p[b
ar], T
[C], M
[t/h
], S
team
Pro
pertie
s: IA
PW
S-IF97
1X
GE
6111FA
75611 k
W
1.0
1 p
13 T
45 %
RH
746.8
m
1 p
13 T
746.8
m
LN
G 1
6.2
9 m
31 T
20 T
LH
V= 2
17
815 k
Wth
15.6
5 p
380 T
14.8
7 p
1328 T
763.1
m
1.0
4 p
606 T
763.1
M
74.9
4 %
N2
12.8
5 %
O2
3.9
12 %
CO
2 7
.395 %
H2O
0.9
023 %
Ar
604 T
763.1
M
2.4
6 m
^3/k
g521.5
m^3
/s
604
511
511
511
499
305
304
269
267
232
232
193
160
160
109 T
763.1
M
1.0
98 m
^3/k
g232.8
m^3
/s
40367 k
W
0.0
36 M
FW
0.0
542 p
34 T
122.7
M
34 T
2.3
23 p
114 T
124.1
M
LT
E
34 T
124.1
M
114 T
2.3
23 p
125 T
126.7 M
9.5
36 p
174 T
126.7
M
IPE
2
9.5
36 p
178 T
15.7
5 M
IPB
9.3
82 p
229 T
13.1
2 M
IPS
1
9.1
73 p
260 T
13.1
2 M
IPS
2
2.619 M
75.3
8 p
233 T
110.8
M
HP
E2
74.0
1 p
285 T
110.8
M
HP
E3
74.0
1 p
290 T
109.7
M
HP
B1
73.4
7 p
309 T
109.7
M
HP
S0
71.5
2 p
586 T
109.7
M
HP
S3
69.1
p 5
84 T
109.7
M
71.52 p 586 T
0.0
01 M
13.1
2 M
8.601 p 258 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-1
0:
Heat
an
d M
ass B
ala
nce –
Ga
s-B
ased
Gen
era
tio
n O
pti
on
2 (
Win
ter
Co
nd
itio
ns)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-26
6.3.2 Location
Regarding the potential location of supply option 2, the same site was selected as already de-
picted for supply option 1 in Figure 6-4.
6.3.3 Air Pollution Emissions
The legal frame and the National targets are explained in detail in section 6.1.3. Calculations
were carried out to demonstrate that the supply option 2 complies with the EU environmental di-
rectives and with all the relevant aspects of the Maltese Legislation.
In the following tables the environmental impact due to potential air pollution emissions is
presented. The air pollution emissions of the investigated supply option:
do not exceed the limit value for NOx emissions;
do not exceed the limit value for SO2 emissions. Natural gas does not cause such
emissions at all;
are 56% below the current Green House Gas emissions (typical unit operation assumed)
and do not exceed the limit value for CO2 emissions.
871
401
921
-
100
200
300
400
500
600
700
800
900
1,000
Business as Usual
(all STs)
Business as Usual
(DPS ST)
Supply Option
Sp
ec
ific
Em
iss
ion
s g
CO
2/k
Wh
.
Figure 6-11: Comparison of Greenhouse Gas Emissions - Gas-Based Generation Option 2
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-27
General Information
# Item 2
1 Plant Name Natural Gas Based Supply Option 2
2 Plant Type Combined Cycle Gas Turbine
3 Unit CCGT 1+1 NG fired
4 State Option
5 Unit_Ident
6 Comments
No Comments
Technical & Operational Data for Emissions (continued)
# Item Dim 2
7 Nominal Capacity MW 114.6
8 Max Capacity Sent-Out (Operation) MW 112.3
9 Min Capacity Sent-Out (Operation) MW 30.8
10 Heat Rate* Coeff A (1+1) - 5,619
11 Heat Rate* Coeff B (1+1) - -10,966
12 Heat Rate* Coeff C (1+1) - 12,336
10a Heat Rate* Coeff A (1+0) 46,433
11a Heat Rate* Coeff B (1+0) -50,173
12a Heat Rate* Coeff C (1+0) 25,219
13 Combustion Temp Coeff A - -742
14 Combustion Temp Coeff B - 1,579
15 Combustion Temp Coeff C - 485
16 Air Rate Lambda Case1 1.0 - 1.09
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ
/ k
Wh
700
800
900
1000
1100
1200
1300
1400
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[co
mb
. te
mp
.]
0
5000
10000
15000
20000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ /
kW
h
Table 6-10: Specifications of D_CC2NGo (1/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-28
NOx Emissions
# Item 2
17 Thermal Nox Coeff. A 1E-21 Fuel Nox Coeff. A NA
18 Thermal Nox Coeff. B 7.72 Fuel Nox Coeff. B NA
19 Fuel Nox Coeff. C NA
20 Thermal NOx Emissions over load (RAW)
21 Specific NOx Emissions in g/kWh Absolute NOx Emissions in tons
Fuel Specifications
22 Initial Primary Fuel Rich gas Natural Gas % of Carbon 75.00%
23 Net Calorific Value kJ/kg 48,156 % of Nitrogen 0.00%
24 Required Fuel at 100% load kg 16,633 % of Sulphur 0.00%
25 Required Combustion Air m³ 9.89 % of Nox Reduc. 50.00%
26 Resulting Exhaust Gas m³ 10.34 % of SO2 Reduc. 0.00%
Fuel NOx Emissions over load (RAW)
Fuel Composition
(Emission Relevant)
Potential Emission Reduction
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
mg/m³
2242
6376
64
107
158
211
255
7
0
50
100
150
200
250
300
13 26 38 51 64 77 90 102 115 128
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
mg/m³
36
65
9075
54
89
131
175
214
13
0
50
100
150
200
250
11 23 34 46 57 69 80 92 103 115
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
Table 6-10: Specifications of D_CC2NGo (2/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-29
CO2 and SOx Emissions
# Item 2
27 Fuel needed at 100% load t 16.63
28 Density of Fuel kg / m³ 0.77
29 CO2 emission at 100% load t 44.85
30 Specific CO2 Emissions in g/kWh Absolute CO2 Emissions in t
31 Specific SOx Emissions in g/kWh Absolute SOx Emissions in tons
Exhaust Gas development in m³ due to Gross Performance
32
29,12351,499
69,655
103,402
135,795152,889
169,723186,792
204,592
86,115
0
50,000
100,000
150,000
200,000
250,000
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
m³ Exhaust Gas
525474
439 422462 446 433 423 417
594
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
13.3
21.9
27.632.3
26.530.0
33.336.8
40.544.9
0
10
20
30
40
50
11 23 34 46 57 69 80 92 103 115
[t CO2]
[MW]
50,832
83,834
105,860 101,558114,808
127,639140,880
155,361171,912
123,762
0
50,000
100,000
150,000
200,000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
m³ Exhaust Gas
n/a
954
803704
462 436 415 401 393 391
1157
0
200
400
600
800
1,000
1,200
1,400
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
n/a
Table 6-10: Specifications of D_CC2NGo (3/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-30
6.4 Economic Description of Gas-Based Generation Option 2 (CCGT 1+1)
6.4.1 Investment Costs of Major Components
The projects implementation plan (already described in section 6.2.1) leads to the investment
cost’s disbursement schedule shown in Table 6-12. The total duration of the project’s implem-
entation is estimated at three years. A lifetime of 25 years is assumed for the supply option 2.
The investment cost in total and for each individual major component is provided in Table 6-11.
In total, the projects investment cost amounts to 74.6 Mio Euro (10% contingencies included).
# Item
1
2
3
4
5
6
7
8
9
10
11
3,292
Plant Startup 603
Contractor's Soft Costs 9,894
Engineering
Investment Costs
in T EUR
Balance of Plant 5,163
Electrical Equipment 5,737
9,698
9,954
672
Gas Turbine incl. Generator 20,853
Steam Turbine Package incl. Generator
Total: 74,550
Heat Recovery Boiler
Cooling Facility/Cooling System
I&C Equipment 853
Civil/Buildings incl. On-Site Transportation 7,812
Table 6-11: Investment Costs of Gas-Based Generation Option 2
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-31
Year n-3 n-2 n-1 n
Disbursement in % 50% 30% 20% Start Year
Table 6-12: Disbursement Schedule of Gas-Based Generation Option 2
The specific investment cost amounts to 664 EUR/kW, approximately 7% less compared to the
gas-based generation option 1.
Figure 6-12 illustrates the investment break down. The dominating cost proportions are (i) the
gas turbine package; (ii) the heat recovery boiler; (iii) soft costs of the contractor and (iv) the
steam turbine package.
28%13%
13%
1%
7%
8%
1% 10%4%
1%
13%
Gas Turbine incl. Generator
Steam Turbine Package incl. Generator
Heat Recovery Boiler
Cooling Facility/Cooling System
Balance of Plant
Electrical Equipment
I&C Equipment
Civil/Buildings incl. On-Site Transportation
Engineering
Plant Startup
Contractor's Soft Costs
Figure 6-12: Investment Cost Break Down of Gas-Based Generation Option 2
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-32
6.4.2 Operational and Maintenance Costs
Gas Supply Costs Estimation
The development of the costs of the supply of gas to the power plant is presented in the below
Table. The year 2011 is selected as the first possible year of the plant’s operation. This assump-
tion takes into account the project’s schedule given in the previous section.
Item Unit 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
EUR/t 204.4 197.7 191.0 191.0 191.0 191.0 194.4 197.7 201.0 201.0
Item Unit 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
EUR/t 204.4 207.7 211.0 214.4 216.0 217.7 217.7 219.4 219.4 221.0
Fuel Supply Costs
(via LNG conversion)
Fuel Supply Costs
(via LNG conversion)
Table 6-13: Gas Supply Costs
Fixed O&M Costs
Fixed costs of operation and maintenance include expenses for staff salaries; insurance, fees
and other cost which remain constant irrespective of the actual quantum of the plant’s electrical
energy sent-out.
The personnel costs are calculated by the estimated number of required staff (25 employees)
and the average annual salary (30 T EUR/a). Based on experiences in similar assignments the
proportion of the remaining fixed operation and maintenance costs is 2.5% of the capital costs.
In total the annual fixed OPEX amount to 2.6 Mio EUR/a.
.
# Item
1
2
Total Annual Fixed OPEX: 2,614
Costs in T EUR/a
Personnel Costs 750
Insurance, Fees and Others 1,864
Table 6-14: Estimate of Annual Fixed OPEX
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-33
Variable O&M Costs
Variable costs of operation and maintenance include the cost of fuel and costs for e.g.
lubricating oil and chemicals which are consumed in proportion to the actual amount of the
plant’s electrical energy sent-out.
The dominating proportion of the variable OPEX is the cost of fuel, which depends on the fuel
supply cost and the amount of fuel utilized. The latter item again depends on the plant’s ef-
ficiency and further on the plant’s operation mode (e.g. full load or partial load; number of
turbines in operation). In the first section of this chapter the plant’s performance parameters are
described in detail. The following economic analysis considers individual operation modes and
the related specific fuel input.
Based on our experience in similar assignment the value of the remaining variable OPEX is
estimated at 2.0 EUR/MWh.
6.4.3 Dynamic Unit Cost Assessment for Option 2
The following chart provides the calculation of the dynamic unit cost of the gas-based local
generation option 2. As far as the actual future operation of the plant is not known (this depends
mainly on the most economic dispatch of the unit as one component of the entire power gene-
ration system; see Work Package III) we provide cost figures over the entire load range.
Exemplarily the calculation in the chart is based on an 85% load assumption. Nevertheless, the
results are shown for different operation modes from full load to partial load. Furthermore, the
DUC trends are illustrated in Figure 6-13. Regarding the expected annual net generation the
option’s maximum availability of 92.1% is taken into consideration in the 100% full load case.
In the selected 85% load case the DUC of the gas-based local generation option 2 amounts to
43.7 EUR/MWh. Only slight fluctuations of the DUC are observed within the plant’s base load
operation. In full load operation the DUC are 4% lower than the reference value. At 70% load
level the DUC are 9% higher than the reference value.
In intermediate and peak load operation (1 GT + 1 ST mode, and 1 GT mode respectively) the
cost figures increase rapidly. At 50%-load an increase of 28% and at 25%-load an increase of
161% is registered in comparison to the reference value.
The plant’s maximum net generation amounts to 906 GWh/a (at maximum availability and full
load).
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-34
Table 6-15: Dynamic Unit Cost of the Gas-Based Option 2
1
G
en
era
l In
form
ati
on
Loca
l Gen
era
tion O
ptio
n 2
p
1.1
Tec
hn
ical
1.2
Eco
no
mic
s
Pla
nt
Typ
e -
-C
CG
T 1
+1
Set
Siz
e (
nom
inal)
MW
11
4.6
Part
ial L
oa
d100
%85%
70%
50
%40%
25%
Tota
l Inve
stm
ent
T E
UR
74,5
50
Set
Capaci
ty (
gro
ss)
MW
11
4.6
96
.87
8.3
58.3
46.0
30.8
Dis
cou
nt
Ra
te%
6.5
%
Set
Capaci
ty (
net)
MW
11
2.3
94
.67
6.2
56.3
45.4
30.3
Life
time
a30
Auxi
liary
Po
wer
MW
2.4
2.2
2.1
1.9
0.6
0.5
Const
ruct
ion P
eri
od
a3
Self
Con
sum
ptio
n%
2.1
%2.3
%2.7
%3.3
%1.3
%1.6
%
Turb
ine
s in
Opera
tion
--
1G
T+
1S
T
1G
T+
1S
T
1G
T+
1S
T
1G
T+
1S
T
1G
T1G
TF
ixed O
PE
X
T E
UR
/a2,6
14
100
%85%
70%
50
%40%
25%
Variable
OP
EX
*E
UR
/MW
h2.0
Net
Heat
Rate
kJ/
kWh
6,9
30
7,1
41
7,4
71
8,1
22
12
,564
15,1
01
Fu
el T
ype
--
Reg
as
LN
G
Pla
nned O
uta
ge
d/a
18
Net
Calo
rific
Valu
ekJ
/kg
48,1
50
Forc
ed O
uta
ge
%/a
3%
Max
Ava
ilabili
ty%
/a92.1
%*
oth
er
tha
n F
ue
l C
osts
2
Ca
sh
Flo
wO
pera
tion a
t 85%
Load
Item
Ye
ar
>>
n-3
n-2
n-1
12
34
510
20
30
Inve
stm
ent
Cost
T E
UR
/a37,2
75
22,3
65
14,9
10
00
00
00
00
Fix
ed
OP
EX
T E
UR
/a0
00
2,6
14
2,6
14
2,6
14
2,6
14
2,6
14
2,6
14
2,6
14
2,6
14
Variab
le O
PE
XT
EU
R/a
00
026
,947
26,1
23
25,2
98
25,2
98
25,2
98
26,5
35
29,0
09
31,1
58
Fuel S
upply
Cost
s (s
peci
fic)
EU
R/t
00
0204
19
8191
191
191
201
221
238
Fuel S
upply
Cost
s (a
bso
lute
)T
EU
R/a
00
025
,279
24,4
55
23,6
30
23,6
30
23,6
30
24,8
67
27,3
41
29,4
90
Fuel I
nput
t/a
00
0123,6
93
12
3,6
93
123,6
93
123,6
93
123,6
93
123,6
93
123
,693
123,6
93
Net
Gene
ratio
nG
Wh/a
00
0834
83
4834
834
834
834
834
834
3
Pre
se
nt
Valu
e
Capita
l T
EU
R8
6,2
72
OP
EX
T E
UR
38
9,4
82
Net
Gene
ratio
nG
Wh
10,8
91
4
Dyn
am
ic U
nit
Co
st
Part
ial L
oad
100%
85%
70
%50%
40%
25
%112
395
478
656
144
928
1
DU
C -
Po
wer
Gen
era
tio
nE
UR
/MW
h41
.94
3.7
47.5
55.8
79.1
113.7
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-35
0
20
40
60
80
100
120
140
- 20.0 40.0 60.0 80.0 100.0 120.0
Plant's Operation - Load (Net) in MW
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
0
20
40
60
80
100
120
140
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Plant's Operation as Percentage of Load
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
-
200
400
600
800
1,000
1,200
1,400
Pla
nt's N
et
Gen
era
tio
n i
n G
Wh
/a
Figure 6-13: Dynamic Unit Cost over Plant’s Load –Gas-Based Option 2
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-36
6.5 Technical Description of Gas-Based Generation Option 3 (2+1 ST R)
6.5.1 Basic Design
For this supply option one of the existing conventional thermal power units of DPS, with the
auxiliary boiler, the steam turbine and the generator, has been modelled in order to recalculate
the design performance of the plant. The model was developed so that the gross output and
heat rate was consistent with data obtained from the station at the conditions described in the
plant documentation. The present technical parameters of the Delimara 60 MW steam turbines
are provided already in Table 1-8 (Specifications of D_ST1e) and respectively in Table 1.10
(Specifications of D_ST2e). Then the auxiliary boiler in the model was replaced by two gas
turbines with two heat recovery steam generators. All steam turbine ports (formerly for feed-
water heater) were closed and a new combined cycle power plant is received.
This power plant is a combined cycle power plant consisting of two gas turbines, two HRSG and
one (existing) condensing steam turbine. The performance data is based on the GT type of
Alstom’s ALS GT8C2 and double pressure HRSG without duct burner firing. On international
level three important suppliers offer such power plant equipment:
General Electrics (GE) Power Systems,
Alstom
Siemens.
The gas turbines are designed with a dual fuel combustion system using LNG (gaseous) as
primary fuel and diesel as secondary fuel. Water injection for NOx reduction when burning diesel
may be considered in order to meet the allowed NOx emission standard. Because of the single
shaft configuration there is a steam turbine clutch installation assumed. A single cycle operation
of the gas turbine is thereby possible and thus the operational flexibility of the plant is increased.
The heat recovery steam generator (HRSG) is equipped with a bypass stack. The design
capacity of the two gas turbines amounts to 55.3 MW (Net) each. As the result of the plant’s
addition by two gas turbines the design capacity of the steam turbine is 49.1 MW (Net).
The heat recovery steam generators (HRSG) are equipped with a bypass stack for simple cycle
operation of the gas turbines in order to increase the operational flexibility of the plant. Both
HRSG produce in total 41.2 kg/s high pressure steam with 87.1 bar and 493 °C and an inter-
mediate pressure steam of 10.3 kg / s with 9.8 bar and 259 °C. For the cooling system an open
loop water cooling with a seawater inlet temperature of 20 °C and an allowable cooling water
temperature rise of 8 K is assumed.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-37
Plant Characteristics Unit Value
Plant Type CCGT 2+1
Set Size (nominal) MW 162.9
Partial Load 100% 85% 70% 50% 30% 20%
Set Capacity (gross) MW 162.9 139.1 111.5 81.3 47.7 33.8
Set Capacity (net) MW 159.6 136.0 108.7 79.2 45.9 33.4
Auxiliary Power MW 3.2 3.1 2.9 2.1 1.8 0.4
Self Consumption % 2.0% 2.2% 2.6% 2.5% 3.8% 1.2%
Turbines in Operation 2GT+1ST 2GT+1ST 2GT+1ST 1GT+1ST 1GT+1ST 1GT
Partial Load 100% 85% 70% 50% 30% 20%
Net Heat Rate kJ/kWh 7,377 7,537 7,897 7,436 8,422 12,874
Planned Outage d/a 30
Forced Outage %/a 3%
Max Availability %/a 88.8%
Table 6-16: Technical Data – Gas-Based Generation Option 3
Maltese local conditions and provided fuel specifications have been considered for the evalu-
ation of the major operational parameters which are provided in Table 6-16. A partial load range
between 100% (full load) and 20% is selected regarding the provision of the operational
characteristics, which can be summarized as follows:
The plant’s self consumption (auxiliary power) drops from 3.2 MW to 0.4 MW in absolute
terms. Related to the plants output the value increases from 2.0% to 2.6% (2 GT + 1 ST
operation); from 2.5% to 3.8% (1 GT + 1 ST operation) and decreases thereafter to only
1.2% (1 GT operation);
The plant’s net heat rate increases from 7,377 kJ/kWh to 12,874 kJ/kWh over the range
of partial load investigated. This is equal to a net efficiency decrease from 48.8% to
28.0%.
Regarding the planned outage duration, the current figure (30 days a year) was applied. It is
assumed that maintenance works for the both GTs will carried out within this time frame. The
addition of a typical forced outage rate for the type of technology (3%) leads to a maximum avai-
lability of the plant of some 88.8%.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-38
The net and gross heat rates of the gas based supply option 3 are shown in the following figure
over the entire load range (calculated on fuel’s NCV). The results of GT Pro calculations are
summarized within the heat and mass balance diagrams in the Figures 6-15 and 6-16. The
calculations are based on the maximum load of the plant during summer and winter conditions.
The comparison of the summer and winter parameters brings out the following results:
The plant’s net capacity during summer amounts to nearly 20 MW less (141.6 MW)
compared to the net capacity during the winter period which is 161.2 MW.
The plants’ net heat rate decreases from 7,522 kJ/kWh during summer to 7,357 kJ/kWh
during winter. This is equal to a net efficiency increase from 47.9% (summer) to 48.9%
(winter).
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-39
Figure 6-14:Gross and Net Heat Rates – Gas-Based Generation Option 3
He
at
Ra
tes
(k
J/k
Wh
) o
f S
up
ply
Op
tio
n 3
- 2
+1 S
T R
NG
fir
ed
0
2,0
00
4,0
00
6,0
00
8,0
00
10,0
00
12,0
00
14,0
00
16,0
00
18,0
00
020
,000
40
,00
060
,000
80
,000
100
,00
012
0,0
00
140
,000
160
,00
0180
,000
Lo
ad
(kW
)
Heat Rate (kJ/kWh)
2+
1 g
ross
HR
2+
1 n
et
HR
1+
1 g
ross
HR
1+
1 n
et
HR
1+
0 g
ross
HR
1+
0 n
et
HR
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-40
GT
MA
ST
ER
17.0
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I - W
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316 0
8-2
1-2
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ase 3
(2+1) re
furb
ishm
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W S
T\C
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FIR
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100
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ad a
t sum
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CC
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2+1 c
onfigura
tion (re
furb
ishm
ent ste
am
pow
er pla
nt), N
G fired
100%
load a
t sum
me
r condit
ions
Net P
ow
er 141
552 k
WLH
V H
eat R
ate
752
2 k
J/k
Wh
p[b
ar], T
[C], M
[t/h
], S
team
Pro
pertie
s: IA
PW
S-IF97
1X
ALS
GT
8C
2 2
X G
T
47392 k
W
1.0
1 p
36 T
70 %
RH
632.2
m
1 p
36 T
632.2
m
LN
G 1
1.0
6 m
20 T
LH
V= 1
47
890 k
Wth
16.2
1 p
430 T
15.4
8 p
1171 T
643.3
m
1.0
4 p
531 T
1286.5
M
72.8
6 %
N2
13.7
6 %
O2
3.1
24 %
CO
2 9
.381 %
H2O
0.8
773 %
Ar
529 T
1286.5
M
2.2
79 m
^3/k
g814.3
m^3
/s
529
462
462
320
318
282
279
256
256
197
165
165
126 T
1286.5
M
1.1
59 m
^3/k
g414.1
m^3
/s
49897 k
W
0.0
5 M
FW
0.1
042 p
47 T
185.4
M
47 T
2.3
23 p
116 T
187.4
M
LT
E
47 T
187.4
M
116 T
2.3
23 p
125 T
190.6 M
10.7
7 p
178 T
190.6
M
IPE
2
10.7
7 p
183 T
40.4
1 M
IPB
10.5
8 p
229 T
37.1
8 M
IPS
1
10.4
p
261 T
37.1
8 M
IPS
2
3.215 M
95.2
6 p
229 T
147.7
M
HP
E2
93.2
8 p
299 T
147.7
M
HP
E3
93.2
8 p
306 T
146.3
M
HP
B1
90.1
4 p
510 T
146.3
M
HP
S3
2.0
6 M
87.1
p 4
93 T
148.3
M
90.14 p 510 T
2.0
6 M
37.1
8 M
9.8 p 259 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-1
5:
Heat
an
d M
ass B
ala
nce –
Ga
s-B
ased
Gen
era
tio
n O
pti
on
3 (
Su
mm
er
Co
nd
itio
ns)
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-41
GT
MA
ST
ER
17.0
.1 L
I - W
. E
isenhart
316 0
8-2
1-2
007 1
3:5
1:1
4 file
=T
:\26\0
400\2
60442_m
alta\0
6_p
roje
ct_
results\G
TP
ro\C
ase 3
(2+1) re
furb
ishm
en
t 60M
W S
T\C
CG
T 2
+1 R
EFU
RB
ISH
ME
NT
ST
NG
FIR
ED
100%
lo
ad a
t w
inte
r co
ndi
CC
GT
2+1 c
onfigura
tion (re
furb
ishm
ent ste
am
pow
er p
lant), N
G fired
100%
load a
t w
inte
r conditio
ns
Net P
ow
er 161209 k
WLH
V H
eat R
ate
7357 k
J/k
Wh
p[b
ar], T
[C], M
[t/h
], S
team
Pro
pertie
s: IA
PW
S-IF97
1X
ALS
GT
8C
2 2
X G
T
55470 k
W
1.0
1 p
13 T
45 %
RH
694.9
m
1 p
13 T
694.9
m
LN
G 1
2.3
2 m
20 T
LH
V= 1
64
714 k
Wth
17.7
5 p
411 T
16.9
5 p
1178 T
707.2
m
1.0
4 p
514 T
1414.4
M
75.4
2 %
N2
14.3
%O
2 3
.205 %
CO
2 6
.17 %
H2O
0.9
081 %
Ar
512 T
1414.4
M
2.1
96 m
^3/k
g862.8
m^3
/s
512
453
453
321
319
285
282
260
260
200
168
168
125 T
1414.4
M
1.1
44 m
^3/k
g449.3
m^3
/s
53513 k
W
0.0
511 M
FW
0.0
543 p
34 T
189.1
M
34 T
2.3
23 p
114 T
191.1
M
LT
E
34 T
191.1
M
114 T
2.3
23 p
125 T
195.1 M
11.1
p
181 T
195.1
M
IPE
2
11.1
p
184 T
45.0
2 M
IPB
10.8
8 p
229 T
40.9
7 M
IPS
1
10.6
7 p
260 T
40.9
7 M
IPS
2
4.075 M
95.2
4 p
233 T
149.6
M
HP
E2
93.2
p
301 T
149.6
M
HP
E3
93.2
p
306 T
148.2
M
HP
B1
90.0
5 p
495 T
148.2
M
HP
S3
87 p
492 T
148.2
M
90.05 p 495 T
40.9
7 M
9.979 p 258 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-1
6:
Heat
an
d M
ass B
ala
nce –
Ga
s-B
ased
Gen
era
tio
n O
pti
on
3 (
Win
ter
Co
nd
itio
ns)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-42
6.5.2 Location
Figure 6-17 shows the location of the existing steam turbines and boilers at the Delimara Power
Station site, which is also the location of the proposed refurbishment measure.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-43
Figure 6-17: Potential Location of Gas-Based Generation Option 3
In the following more details of the unit’s geometry are provided. The first two drawings depict
the gas turbine package (Figure 6-19). The total length of the package is calculated at approx.
22 meters. The width of one package is calculated at approx. 5 meters.
Figure 6-20 shows the geometry of the heat recovery steam generator. The total length amounts
to some 27 meters. The width of one HRSG amounts to 7 meters. Summarizing the dimension
of the plant’s components the below figure provides a suggestion regarding the arrangement of
the required two HRSGs and two GTs. As the result a square of 27 x 27 meters is calculated
and considered as realizable.
Figure 6-18: Suggestion regarding the Formation of HRSGs and GTs
GT
GT
HR
SG
HR
SG
ap
pro
x. 2
7 m
approx. 27 m
GT
GT
HR
SG
HR
SG
ap
pro
x. 2
7 m
approx. 27 m
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-44
FOR QUALITATIVE INDICATION ONLY
Thermoflow, Inc.
PEACE/GT MASTER 17.0.2
Date: 11.12.07
Company: Lahmeyer International GmbH
User: LI - W. Eisenhart
C:\TFLOW17\MYFILES\GTMAS.GTM
Drawing No:
GAS TURBINE PACKAGE
ELEVATION
GE 6561B 133
A A
B B
C C
D D
E E
F F
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A B C D E F G H I J
SHAPE, DIMENSIONS & SCALE ARE APPROXIMATE
11.4 m 3.4 m 6.5 m 4.4 m 11.6 m - - - - -
A
B
C D
E
FOR QUALITATIVE INDICATION ONLY
Thermoflow, Inc.
Date: 11.12.07
Company: Lahmeyer International GmbH
User: LI - W. Eisenhart
C:\TFLOW17\MYFILES\GTMAS.GTM
Drawing No:
GAS TURBINE PACKAGE
PLAN
GE 6561B 133
A A
B B
C C
D D
E E
F F
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A B C D E F G H I J
SHAPE, DIMENSIONS & SCALE ARE APPROXIMATE
3.4 m 21.9 m 2.5 m 2.6 m - - - - - -
A
B
C D
Figure 6-19: Dimensions of one GT Package
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-45
FOR QUALITATIVE INDICATION ONLY
Thermoflow, Inc.
PEACE/GT MASTER 17.0.2
Date: 11.12.07
Company: Lahmeyer International GmbH
User: LI - W. Eisenhart
C:\TFLOW17\MYFILES\GTMAS.GTM
Drawing No:
HEAT RECOVERY STEAM GENERATOR
ELEVATION
A A
B B
C C
D D
E E
F F
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A B C D E F G H I J
A C D E
F
G
H
5 m - 7.1 m 10.9 m 2.1 m 22.2 m 12.1 m 2.7 m - -
FOR QUALITATIVE INDICATION ONLY
Thermoflow, Inc.
PEACE/GT MASTER 17.0.2
Date: 11.12.07
Company: Lahmeyer International GmbH
User: LI - W. Eisenhart
C:\TFLOW17\MYFILES\GTMAS.GTM
Drawing No:
HEAT RECOVERY STEAM GENERATOR
PLAN
A A
B B
C C
D D
E E
F F
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
A B C D E F G H I J
A C D E
F
5 m - 7.1 m 10.9 m 2.1 m 3.7 m 3.1 m - - -
G
Figure 6-20: Dimensions of one HRSG
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-46
6.5.3 Air Pollution Emissions
The legal frame and the National targets for local generation options are explained in detail in
section 6.1.3. In the following tables the environmental impact due to potential air pollution
emissions is presented. The air pollution emissions of the investigated supply option:
do not exceed the limit value for NOx emissions;
do not exceed the limit value for SO2 emissions. Natural gas does not cause such
emissions at all;
are 56% below the current Green House Gas emissions (typical unit operation assumed)
and do not exceed the limit value for CO2 emissions.
871
420
921
-
100
200
300
400
500
600
700
800
900
1,000
Business as Usual
(all STs)
Business as Usual
(DPS ST)
Supply Option
Sp
ec
ific
Em
iss
ion
s g
CO
2/k
Wh
.
Figure 6-21: Comparison of Greenhouse Gas Emissions - Gas-Based Generation Option 3
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-47
General Information
# Item 3
1 Plant Name Natural Gas Based Supply Option 3 (Refurbishment)
2 Plant Type Combined Cycle Gas Turbine
3 Unit CCGT 2+1 NG fired
4 State Option
5 Unit_Ident
6 Comments
No Comments
Technical & Operational Data for Emissions (continued)
# Item Dim 3
7 Nominal Capacity MW 162.9
8 Max Capacity Sent-Out (Operation) MW 159.6
9 Min Capacity Sent-Out (Operation) MW 38.6
10 Heat Rate* Coeff A (2+1) - 3,764
11 Heat Rate* Coeff B (2+1) - -7,944
12 Heat Rate* Coeff C (2+1) - 11,566
10a Heat Rate* Coeff A (1+1) 18,027
11a Heat Rate* Coeff B (1+1) -18,884
12a Heat Rate* Coeff C (1+1) 12,381
13 Combustion Temp Coeff A - -742
14 Combustion Temp Coeff B - 1,579
15 Combustion Temp Coeff C - 485
16 Air Rate Lambda Case1 1.0 - 1.09
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ
/ k
Wh
700
800
900
1000
1100
1200
1300
1400
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[co
mb
. te
mp
.]
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ
/ k
Wh
Table 6-17: Specifications of D_CC3NGo (1/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-48
NOx Emissions
# Item 3
17 Thermal Nox Coeff. A 1E-21 Fuel Nox Coeff. A NA
18 Thermal Nox Coeff. B 7.72 Fuel Nox Coeff. B NA
19 Fuel Nox Coeff. C NA
20 Thermal NOx Emissions over load (RAW)
21 Specific NOx Emissions in g/kWh Absolute NOx Emissions in tons
Fuel Specifications
22 Initial Primary Fuel Rich gas Natural Gas % of Carbon 75.00%
23 Net Calorific Value kJ/kg 48,156 % of Nitrogen 0.00%
24 Required Fuel at 100% load kg 24,985 % of Sulphur 0.00%
25 Required Combustion Air m³ 9.89 % of Nox Reduc. 50.00%
26 Resulting Exhaust Gas m³ 10.34 % of SO2 Reduc. 0.00%
Fuel Composition
(Emission Relevant)
Potential Emission Reduction
Fuel NOx Emissions over load (RAW)
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0 0 0 0 0 0 0 0 0 0
mg/m³
2242
6376
64
107
158
211
255
7
0
50
100
150
200
250
300
13 26 38 51 64 77 90 102 115 128
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0 0 0 0 0 0 0 0 0 0
mg/m³
28
53
7896
80
134
199
265
322
9
0
50
100
150
200
250
300
350
16 33 49 65 81 98 114 130 147 163
kg Nox
RAW
0.0
50.0
100.0
150.0
200.0
Table 6-15: Specifications of D_CC3NGo (2/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-49
CO2 and SOx Emissions
# Item 3
27 Fuel needed at 100% load t 24.99
28 Density of Fuel kg / m³ 0.77
29 CO2 emission at 100% load t 67.38
30 Specific CO2 Emissions in g/kWh Absolute CO2 Emissions in t
31 Specific SOx Emissions in g/kWh Absolute SOx Emissions in tons
Exhaust Gas development in m³ due to Gross Performance
32
29,12351,499
69,655
103,402
135,795152,889
169,723186,792
204,592
86,115
0
50,000
100,000
150,000
200,000
250,000
0 0 0 0 0 0 0 0 0 0
m³ Exhaust Gas
525474
439 422462 446 433 423 417
594
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
9.717.0
22.828.1
34.0
44.650.1
55.661.3
67.4
0
10
20
30
40
50
60
70
80
16 33 49 65 81 98 114 130 147 163
[t CO2]
[MW]
37,316
65,20987,460
130,165
171,072192,117
213,135234,914
258,244
107,851
0
50,000
100,000
150,000
200,000
250,000
300,000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
m³ Exhaust Gas
n/a
522467
432 417457 440 427 418 414
598
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
n/a
Table 6-15: Specifications of D_CC3NGo (3/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-50
6.6 Economic Description of Gas-Based Generation Option 3 (2+1 ST R)
6.6.1 Investment Costs of Major Components
Under consideration of the project’s implementation plan (already described in section 6.2.1)
and taking into account the already existing components, an implementation duration of two
years is estimated. The investment cost’s disbursement schedule is shown in Table 6-19. The
lifetime of the supply option 3 is related to the remaining lifetime of the existing steam turbine
which is estimated at 15 years (see Table 1-8 Specifications of D_ST1e).
The investment cost in total and for each individual major component is provided in Table 6-18.
In total, the projects investment cost amounts to 88.1 Mio Euro (10% contingencies included).
# Item
1
2
3
4
5
6
7
8
9 10,926 Contractor's Soft Costs
Investment Costs
in T EUR
I&C Equipment 1,430
Civil/Buildings incl. On-Site Transportation 8,332
17,027
6,576
7,289
Gas Turbine Package incl. Generator 32,792
Heat Recovery Boiler
Total: 88,063
Balance of Plant
Electrical Equipment
Engineering 2,933
Plant Startup 758
Table 6-18: Investment Costs of Gas-Based Generation Option 3
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-51
Year n-2 n-1 n
Disbursement in % 60% 40% Start Year
Table 6-19: Disbursement Schedule of Gas-Based Generation Option 3
The specific investment cost amounts to 552 EUR/kW, approximately 23% less compared to the
gas-based generation option 1, respectively 17% less compared to the gas-based generation
option 2.
Figure 6-22 illustrates the investment break down. The dominating cost proportions are (i) the
gas turbine package; (ii) the heat recovery boiler; (iii) soft costs of the contractor and (iv) the civil
works.
37%
19%
7%
8%2% 9%
3%
1%
12%
Gas Turbine Package incl. Generator and Air
inlet cooling/heating if applicable
Heat Recovery Boiler
Balance of Plant
Electrical Equipment
I&C Equipment
Civil/Buildings incl. On-Site Transportation
Engineering
Plant Startup
Contractor's Soft Costs
Figure 6-22: Investment Cost Break Down of Gas-Based Generation Option 3
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-52
6.6.2 Operational and Maintenance Costs
Gas Supply Costs Estimation
As the result of the assessments in the chapters 1 to 5 the development of the costs of the
supply of gas to the power plant is presented in the below Table. The year 2011 is selected as
the first possible year of the plant’s operation. This assumption takes into account the project’s
schedule given in the previous section.
Item Unit 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
EUR/t 204.4 197.7 191.0 191.0 191.0 191.0 194.4 197.7 201.0 201.0
Item Unit 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
EUR/t 204.4 207.7 211.0 214.4 216.0 217.7 217.7 219.4 219.4 221.0
Fuel Supply Costs
(via LNG conversion)
Fuel Supply Costs
(via LNG conversion)
Table 6-20: Gas Supply Costs
Fixed O&M Costs
Fixed costs of operation and maintenance include expenses for staff salaries; insurance, fees
and other cost which remain constant irrespective of the actual quantum of the plant’s electrical
energy sent-out.
The personnel costs are calculated by the estimated number of additionally required staff
(10 employees) and the average annual salary (30 T EUR/a). Based on experiences in similar
assignments the proportion of the remaining fixed operation and maintenance costs is 2.5% of
the capital costs.
.
# Item
1
2
Total Annual Fixed OPEX: 2,502
Costs in T EUR/a
Personnel Costs 300
Insurance, Fees and Others 2,202
Table 6-21: Estimate of Annual Fixed OPEX
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-53
Variable O&M Costs
Variable costs of operation and maintenance include the cost of fuel and costs for e.g.
lubricating oil and chemicals which are consumed in proportion to the actual amount of the
plant’s electrical energy sent-out.
The dominating proportion of the variable OPEX is the cost of fuel, which depends on the fuel
supply cost and the amount of fuel utilized. The latter item again depends on the plant’s
efficiency and further on the plant’s operation mode (e.g. full load or partial load; number of
turbines in operation). In the first section of this chapter the plant’s performance parameters are
described in detail. The following economic analysis considers individual operation modes and
the related specific fuel input.
Based on our experience in similar assignment the value of the remaining variable OPEX is esti-
mated at 4.0 EUR/MWh.
6.6.3 Dynamic Unit Cost Assessment for Option 3
The following chart provides the calculation of the dynamic unit cost of the gas-based local
generation option 3. As far as the actual future operation of the plant is not known (this depends
mainly on the most economic dispatch of the unit as one component of the entire power gene-
ration system; see Work Package III) we provide cost figures over the entire load range.
Exemplarily the calculation in the chart is based on an 85% load assumption. Nevertheless, the
results are shown for different operation modes from full load to partial load. Furthermore, the
DUC trends are illustrated in Figure 6-23. Regarding the expected annual net generation the
option’s maximum availability of 88.8% is taken into consideration in the 100% full load case.
In the selected 85% load case the DUC of the gas-based local generation option 3 amounts to
52.2 EUR/MWh. Fluctuations of the DUC are observed within the plant’s base load operation. In
full load operation the DUC are 2% lower than the reference value. At 70% load level the DUC
are 11% higher than the reference value.
In intermediate and peak load operation (1 GT + 1 ST mode, and 1 GT mode respectively) the
cost figures increase rapidly. At 50%-load an increase by 24% and at 20%-load an increase by
150% is registered in comparison to the reference value.
The plant’s maximum annual net generation amounts to 794 GWh/a (at maximum availability
and full load). This quantum considers exclusively the additionality of the repowering measure.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-54
Table 6-22: Dynamic Unit Cost of the Gas-Based Option 3
1
G
en
era
l In
form
ati
on
Loca
l Ge
ne
ratio
n O
ptio
n 3
(C
CG
T 2
+1
ST
R)
p
1.1
Te
ch
nic
al
1.2
Ec
on
om
ics
Pla
nt
Typ
e -
-C
CG
T 2
+1
Se
t S
ize
(n
om
ina
l)M
W1
62.9
Pa
rtia
l Lo
ad
100
%8
5%
70
%5
0%
30%
20
%T
ota
l In
vest
me
nt
T E
UR
88
,06
3
Se
t C
ap
aci
ty (
gro
ss)
MW
16
2.9
139
.11
11.5
81
.34
7.7
33
.8D
isco
un
t R
ate
%6
.5%
Se
t C
ap
aci
ty (
ne
t)M
W1
59.6
136
.01
08.7
79
.24
5.9
33
.4L
ifetim
ea
15
Au
xilia
ry P
ow
er
MW
3.2
3.1
2.9
2.1
1.8
0.4
Co
nst
ruct
ion
Pe
rio
da
2
Se
lf C
on
sum
ptio
n%
2.0
%2
.2%
2.6
%2.5
%3
.8%
1.2
%
Tu
rbin
es
in O
pera
tion
--
2G
T+
1S
T2G
T+
1S
T2
GT
+1
ST
1G
T+
1S
T
1G
T+
1S
T1G
TF
ixed O
PE
X
T E
UR
/a2
,502
100
%8
5%
70
%5
0%
30%
20
%V
ari
able
OP
EX
*E
UR
/MW
h4.0
Net
He
at
Ra
te
kJ/k
Wh
7,3
77
7,5
37
7,8
97
7,4
36
8,4
22
12
,874
Fu
el T
ype
--
Reg
as
LN
G
Pla
nn
ed
Ou
tag
ed
/a3
0N
et
Ca
lori
fic V
alu
ekJ
/kg
48
,15
0
Fo
rce
d O
uta
ge
%/a
3%
Ma
x A
vaila
bili
ty%
/a8
8.8
%*
oth
er
tha
n F
ue
l C
osts
2
Ca
sh
Flo
wO
pe
ratio
n a
t 8
5%
Lo
ad
Ite
mY
ea
r >
>n
-3n
-2n
-11
23
45
10
12
15
Inve
stm
en
t C
ost
T E
UR
/a0
52
,838
35
,22
50
00
00
00
0
Fix
ed
OP
EX
T E
UR
/a0
00
2,5
02
2,5
02
2,5
02
2,5
02
2,5
02
2,5
02
2,5
02
2,5
02
Va
ria
ble
OP
EX
T E
UR
/a0
00
27
,23
926
,449
25
,66
025
,660
25
,66
02
6,8
44
27
,63
42
8,6
21
Fu
el S
up
ply
Co
sts
(spe
cific
)E
UR
/t0
00
20
419
81
91
19
11
91
201
20
82
16
Fu
el S
up
ply
Co
sts
(ab
solu
te)
T E
UR
/a0
00
24
,21
223
,422
22
,63
222
,632
22
,63
22
3,8
17
24
,60
62
5,5
93
Fu
el I
np
ut
t/a
00
011
8,4
67
11
8,4
67
11
8,4
67
11
8,4
67
11
8,4
67
11
8,4
67
11
8,4
67
11
8,4
67
Net
Ge
ne
ratio
n (
min
us
exi
sitn
g)
GW
h/a
00
07
57
75
77
57
75
77
57
757
75
77
57
3
Pre
sen
t V
alu
e
Cap
ital
T E
UR
97
,44
5
OP
EX
T E
UR
274,0
65
Net
Ge
ne
ratio
n (
min
us
exi
sitn
g)
GW
h7
,11
6
4
Dyn
am
ic U
nit
Co
st
Pa
rtia
l L
oa
d10
0%
85
%7
0%
50%
30
%2
0%
15
96
13
57
111
87
98
47
93
19
DU
C -
Po
we
r G
en
era
tio
nE
UR
/MW
h5
1.4
52
.25
8.2
64
.99
0.0
13
1.1
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-55
0
20
40
60
80
100
120
140
- 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0
Plant's Operation - Load (Net) in MW
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
0
20
40
60
80
100
120
140
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Plant's Operation as Percentage of Load
Dyn
am
ic U
nit
Co
st
EU
R/M
Wh
-
200
400
600
800
1,000
1,200
1,400
Pla
nt's N
et
Gen
era
tio
n i
n G
Wh
/a
Figure 6-23: Dynamic Unit Cost over Plant’s Load – Gas-Based Option 3
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-56
6.7 Technical Description of Gas-Based Generation Option 4 (2+1 GT R)
6.7.1 Basic Design
This supply option one deals with the re-powering of the two existing GTs at the Delimara Power
Station site. The specifications of these turbines are provided in Table 1.12 (Specifications of
D_GT1e) and respectively Table 1.13 (Specifications of D_GT2e).
Except the consideration of two already existing (former) open cycle gas turbines, the general
layout of the combined cycle plant is comparable to that one described in detail in the chapter
“Technical Description of the Gas-Based Generation Option 1 (CCGT 2+1)”.
The gas turbines are designed with a dual fuel combustion system using LNG (gaseous) as
primary fuel. As the result of the refurbishment, the design capacity of the gas turbines amounts
to 38 MW (Net) each. The design capacity of the steam turbine is 38.5 MW (Net). For the
cooling system an open loop water cooling with a seawater inlet temperature of 20 °C and an
allowable cooling water temperature rise of 8 K is assumed.
Plant Characteristics Unit Value
Plant Type CCGT 2+1
Set Size (nominal) MW 117.8
Partial Load 100% 85% 75% 50% 30% 20%
Set Capacity (gross) MW 117.8 99.6 87.4 58.6 36.4 23.5
Set Capacity (net) MW 115.3 97.2 85.1 56.9 34.9 23.2
Auxiliary Power MW 2.5 2.4 2.3 1.7 1.5 0.3
Self Consumption % 2.1% 2.4% 2.6% 2.8% 4.1% 1.2%
Turbines in Operation 2GT+1ST 2GT+1ST 2GT+1ST 1GT+1ST 1GT+1ST 1GT
Partial Load 100% 85% 75% 50% 30% 20%
Net Heat Rate kJ/kWh 7,513 7,599 7,847 7,606 8,551 12,911
Planned Outage d/a 20
Forced Outage %/a 3%
Max Availability %/a 91.5%
Table 6-23: Technical Data – Gas-Based Generation Option 4
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-57
The heat recovery steam generators (HRSG) are equipped with a bypass stack for simple cycle
operation of the gas turbines in order to increase the operational flexibility of the plant. Most
important for the steam cycle efficiency is the HRSG configuration and design. Both HRSG
produce in total 32.6 kg / s high pressure steam with 67.95 bar and 518 °C and an intermediate
pressure steam of 5.82 kg / s with 8.3 bar and 259 °C.
Table 6-23 provides the general technical parameters of the supply option 4 (design conditions).
A partial load range between 100% (full load) and 20% is selected regarding the provision of the
operational characteristics, which can be summarized as follows:
The plant’s self consumption (auxiliary power) drops from 2.5 MW to 0.3 MW in absolute
terms. Related to the plants output the value increases from 2.1% (2 GT + 1 ST operati-
on) to 4.1% (1 GT + 1 ST operation) and decreases then to some 1.2% (1 GT operati-
on);
The plant’s net heat rate increases from 7,513 kJ/kWh to nearly 13,000 kJ/kWh over the
entire range of partial load. This is equal to a net efficiency decrease from 47.9% to
27.9%.
Assuming outage characteristics of an average of 20 days a year for the units’ maintenance and
a 3% forced outage, the maximum availability of the plant is expected to amount 91.5% over a
year.
The net and gross heat rates of the gas based supply option 4 are shown in the following figure
over the entire load range (calculated on fuel’s NCV). The results of GT Pro calculations are
summarized within the heat and mass balance diagrams in the Figures 6-25 and 6-26. The
calculations are based on the maximum load of the plant during summer and winter conditions.
The comparison of the summer and winter parameters brings out the following results:
The plant’s net capacity during summer amounts to only 87% (102.0 MW) compared to
the net capacity during the winter period by some 116.8 MW. Our analysis of the existing
system already brought out similar capacity levels in relation to the temperature
fluctuations in Malta (see work package I);
The plants’ net heat rate decreases from 7,650 kJ/kWh during summer to 7,484 kJ/kWh
during winter. This is equal to a net efficiency increase from 47.1% (summer) to 48.1%
(winter).
As mentioned at the beginning of this section, the configuration of this gas-based generation
option number 4 is very similar to the configuration of the new CCGT evaluated as gas-based
generation option number 1. The comparison of the net efficiencies between both alternatives
provides only a slight derating of the efficiency by 0.5 %-points.
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-58
Figure 6-24: Gross and Net Heat Rates – Gas-Based Generation Option 4
Heat
Rate
s (
kJ/k
Wh
) o
f S
up
ply
Op
tio
n 4
- 2
+1 G
T R
NG
fir
ed
0
2,0
00
4,0
00
6,0
00
8,0
00
10,0
00
12,0
00
14,0
00
16,0
00
020,0
00
40,0
00
60,0
00
80,0
00
100,0
00
120,0
00
140,0
00
Lo
ad
(kW
)
Heat Rate (kJ/kWh)2+
1 g
ross H
R
2+
1 n
et
HR
1+
1 g
ross H
R
1+
1 n
et
HR
1+
0 g
ross H
R
1+
0 n
et
HR
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-59
GT
MA
ST
ER
17.0
.1 L
I - W
. E
isenha
rt
316 0
8-2
9-2
007 1
2:3
8:0
6 fi
le=
T:\2
6\0
400\2
60442_
malta\0
6_p
roje
ct_
res
ults\G
TP
ro\C
ase 4
(2+
1) re
furb
ish
me
nt 2x3
7M
W G
T\N
G fired
\CC
GT
2+
1 R
EF
UR
BIS
HM
EN
T N
G F
IRE
D 1
00%
loa
d a
t sum
m
CC
GT
2+1 c
onfigura
tion (re
furb
ishm
ent o
f sin
gle
-cyc
le p
lan
t),
NG
fir
ed
100
% load a
t sum
mer co
ndit
ions
Net P
ow
er 101
978 k
WLH
V H
eat R
ate
765
0
kJ
/kW
h
p[b
ar], T
[C], M
[t/h
], S
team
Pro
pertie
s: IA
PW
S-IF
97
1X
GE
654
1B
2 X
GT
3275
7 k
W
1.0
1 p
36 T
70 %
RH
445.8
m
1 p
36 T
445
.8 m
LN
G 8
.102
m
20 T
LH
V= 1
08
352
kW
th
10.7
6 p
368 T
10.3
3 p
109
9 T
453.9
m
1.0
4 p
558 T
907.8
M
72
.78
%N
2 1
3.5
2 %
O2
3.2
41
%C
O2
9.5
81
%H
2O
0.8
76
4 %
Ar
55
6 T
90
7.8
M
2.3
58 m
^3/k
g594.5
m^3
/s
556
4
84
484
484
47
3
302
3
01
2
71
268
239
239
19
0
161
1
61
119 T
907.8
M
1.1
39 m
^3/k
g287.3
m^3
/s
38875 k
W
0.0
372
M
FW
0.1
035 p
46 T
138.2
M
46 T
2.3
23 p
116
T
139
.7 M
LT
E
46 T
139.7
M
11
6 T
2.3
23 p
125 T
142.1 M
9.1
49 p
171 T
142.1
M
IPE
2
9.1
49 p
176
T
23.4
2 M
IPB
8.9
81 p
228 T
20.9
6 M
IPS
1
8.8
43 p
261 T
20.9
6 M
IPS
2
2.467 M
74
.04
p
23
0 T
11
5.5
M
HP
E2
72.7
3 p
282 T
115.5
M
HP
E3
72.7
3 p
288 T
114.4
M
HP
B1
72.0
5 p
309
T
114
.4 M
HP
S0
70.3
2 p
535 T
115.8
M
HP
S3
1.5
1 M
67.9
5 p
518
T 1
17
.3 M
70.32 p 535 T
1.4
6 M
2.9
7 M
20.9
6 M
8.331 p 259 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-2
5:
Heat
an
d M
ass B
ala
nce –
Ga
s-B
ased
Gen
era
tio
n O
pti
on
4 (
Su
mm
er
Co
nd
itio
ns)
MA
LT
A R
ES
OU
RC
ES
AU
TH
OR
ITY
Energ
y I
nte
rco
nnection E
uro
pe -
Malta
Marc
h 2
008
Fin
al
Rep
ort
– W
ork
Packag
e I
IA
LI
2604
42
Page 6
-60
GT
MA
ST
ER
17.0
.1 L
I - W
. E
isenh
art
316 0
8-2
9-2
007 1
2:3
8:5
3 file
=T
:\26\0
400\2
60442_m
alta\0
6_p
roje
ct_
res
ults\G
TP
ro\C
ase 4
(2+1) re
furb
ishm
en
t 2
x37M
W G
T\N
G fired\C
CG
T 2
+1 R
EFU
RB
ISH
ME
NT
NG
FIR
ED
100%
load a
t w
inte
CC
GT
2+1 c
onfigura
tion (re
furb
ishm
ent of sin
gle
-cyc
le p
ow
er pla
nt)
, N
G fired
100%
load a
t w
inte
r cond
itio
ns
Net P
ow
er 116781 k
WLH
V H
eat R
ate
748
4
kJ
/kW
h
p[b
ar], T
[C], M
[t/h
], S
team
Pro
pertie
s: IA
PW
S-IF9
7
1X
GE
6541B
2 X
GT
38504 k
W
1.0
1 p
13
T
45
%R
H
49
6.4
m
1 p
13 T
496.4
m
LN
G 9
.077 m
20 T
LH
V= 1
21
387 k
Wth
11.9
3 p
354 T
11.4
5 p
1105 T
505.4
m
1.0
4 p
540 T
1010.9
M
75.3
5 %
N2
14.1
%O
2 3
.303 %
CO
2 6
.34 %
H2O
0.9
073 %
Ar
538 T
1010.9
M
2.2
68 m
^3/k
g636.8
m^3
/s
53
8
476
476
476
466
305
303
275
272
243
243
193
164
164
118 T
1010.9
M
1.1
24 m
^3/k
g315.7
m^3
/s
42275 k
W
0.0
38
4 M
FW
0.0
543 p
34 T
142.7
M
34 T
2.3
23 p
114 T
144.3
M
LT
E
34
T 1
44.3
M
114 T
2.3
23 p
12
5 T
147.3 M
9.5
53 p
174 T
147.3
M
IPE
2
9.5
53 p
178 T
26.5
M
IPB
9.3
55 p
229 T
23.4
3 M
IPS
1
9.1
92
p
261 T
23.4
3 M
IPS
2
3.06 M
75.4
p
233 T
120.6
M
HP
E2
73.9
8 p
285 T
120.6
M
HP
E3
73.9
8 p
290 T
119.4
M
HP
B1
73.2
6 p
309 T
119.4
M
HP
S0
71.4
8 p
519 T
119.4
M
HP
S3
69.0
6 p
517
T 1
19
.4 M
71.48 p 519 T
23.4
3 M
8.604 p 259 T
Abbreviation:
p -pressure in bar
M -mass flow in kg / s
T -temperature in °C
Colours:
red -gas, air and exhaust gas flow
violet-high pressure steam
light blue-intermediate pressure steam
dark blue-feed water and water injection to gas turbine
Fig
ure
6-2
6:
Heat
an
d M
ass B
ala
nce –
Ga
s-B
ased
Gen
era
tio
n O
pti
on
4 (
Win
ter
Co
nd
itio
ns)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-62
6.7.2 Location
Figure 6-27 shows the location of the existing gas turbines at the Delimara Power Station site,
which is also the location of the proposed re-powering measure.
Figure 6-27: Potential Location of Gas-Based Generation Option 4
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-63
6.7.3 Air Pollution Emissions
The legal frame and the National targets are explained in detail in section 6.1.3. Calculations
were carried out to demonstrate that the supply option 4 complies with the EU environmental
directives and with all the relevant aspects of the Maltese Legislation.
In the following tables the environmental impact due to potential air pollution emissions is
presented. The air pollution emissions of the investigated supply option:
do not exceed the limit value for NOx emissions;
do not exceed the limit value for SO2 emissions. Natural gas does not cause such
emissions at all;
are 53% below the current Green House Gas emissions (typical unit operation assumed)
and do not exceed the limit value for CO2 emissions.
871
430
921
-
100
200
300
400
500
600
700
800
900
1,000
Business as Usual
(all STs)
Business as Usual
(DPS ST)
Supply Option
Sp
ec
ific
Em
iss
ion
s g
CO
2/k
Wh
.
Figure 6-28: Comparison of Greenhouse Gas Emissions - Gas-Based Generation Option 4
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-64
General Information
# Item 4
1 Plant Name Natural Gas Based Supply Option 4 (Refurbishment)
2 Plant Type Combined Cycle Gas Turbine
3 Unit CCGT 2+1 NG fired
4 State Option
5 Unit_Ident
6 Comments
No Comments
Technical & Operational Data for Emissions (continued)
# Item Dim 4
7 Nominal Capacity MW 117.8
8 Max Capacity Sent-Out (Operation) MW 115.3
9 Min Capacity Sent-Out (Operation) MW 34.9
10 Heat Rate* Coeff A (2+1) - 6,725
11 Heat Rate* Coeff B (2+1) - -12,970
12 Heat Rate* Coeff C (2+1) - 13,748
10a Heat Rate* Coeff A (1+1) 28,344
11a Heat Rate* Coeff B (1+1) -27,591
12a Heat Rate* Coeff C (1+1) 14,312
13 Combustion Temp Coeff A - -742
14 Combustion Temp Coeff B - 1,579
15 Combustion Temp Coeff C - 485
16 Air Rate Lambda Case1 1.0 - 1.09
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ /
kW
h
700
800
900
1000
1100
1200
1300
1400
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[co
mb
. te
mp
.]
0
5000
10000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
kJ
/ k
Wh
Table 6-24: Specifications of D_CC4NGo (1/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-65
NOx Emissions
# Item 4
17 Thermal Nox Coeff. A 1E-21 Fuel Nox Coeff. A NA
18 Thermal Nox Coeff. B 7.72 Fuel Nox Coeff. B NA
19 Fuel Nox Coeff. C NA
20 Thermal NOx Emissions over load (RAW)
21 Specific NOx Emissions in g/kWh Absolute NOx Emissions in tons
Fuel Specifications
22 Initial Primary Fuel Rich gas Natural Gas % of Carbon 75.00%
23 Net Calorific Value kJ/kg 48,156 % of Nitrogen 0.00%
24 Required Fuel at 100% load kg 18,354 % of Sulphur 0.00%
25 Required Combustion Air m³ 9.89 % of Nox Reduc. 50.00%
26 Resulting Exhaust Gas m³ 10.34 % of SO2 Reduc. 0.00%
Fuel Composition
(Emission Relevant)
Potential Emission Reduction
Fuel NOx Emissions over load (RAW)
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0 0 0 0 0 0 0 0 0 0
mg/m³
2242
6376
64
107
158
211
255
7
0
50
100
150
200
250
300
13 26 38 51 64 77 90 102 115 128
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
0.0
0.5
1.0
1.5
2.0
2.5
10% 20% 30% 40% 50% 60% 70% 80% 90%
[g/kWh]
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0
200
400
600
800
1,000
1,200
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
mg/m³
0
200
400
600
800
1,000
1,200
0 0 0 0 0 0 0 0 0 0
mg/m³
22
4057
7160
99
145
193
237
8
0
50
100
150
200
250
12 24 35 47 59 71 82 94 106 118
kg Nox
RAW
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
Table 6-20: Specifications of D_CC4NGo (2/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-66
CO2 and SOx Emissions
# Item 4
27 Fuel needed at 100% load t 18.35
28 Density of Fuel kg / m³ 0.77
29 CO2 emission at 100% load t 49.50
30 Specific CO2 Emissions in g/kWh Absolute CO2 Emissions in t
31 Specific SOx Emissions in g/kWh Absolute SOx Emissions in tons
Exhaust Gas development in m³ due to Gross Performance
32
29,12351,499
69,655
103,402
135,795152,889
169,723186,792
204,592
86,115
0
50,000
100,000
150,000
200,000
250,000
0 0 0 0 0 0 0 0 0 0
m³ Exhaust Gas
525474
439 422462 446 433 423 417
594
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
7.813.1
17.020.6
25.1
33.236.8
40.544.7
49.5
0
10
20
30
40
50
60
12 24 35 47 59 71 82 94 106 118
[t CO2]
[MW]
29,927
50,20165,123
96,109
127,232140,955
155,261171,171
189,703
78,992
0
50,000
100,000
150,000
200,000
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
m³ Exhaust Gas
n/a
556
481437 426
470 446 430 421 420
663
0
200
400
600
800
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
[g/kWh]
n/a
Table 6-20: Specifications of D_CC4NGo (3/3)
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-67
6.8 Economic Description of Gas-Based Generation Option 4 (2+1 GT R)
6.8.1 Investment Costs of Major Components
Under consideration of the project’s implementation plan (already described in section 6.2.1)
and taking into account the already existing components, an implementation duration of two
years is estimated. The investment cost’s disbursement schedule is shown in Table 6-26.
The lifetime of the supply option 4 is related to the remaining lifetime of the existing gas turbines
which is estimated at approximately 15 years (see Table 1.12 Specifications of D_GT1e res-
pectively Table 1.13 Specifications of D_GT2e).
The investment cost in total and for each individual major component is provided in Table 6-25.
In total, the projects investment cost amounts to 54.4 Mio Euro (10% contingencies included).
# Item
1
2
3
4
5
6
7
8
9
10
Heat Recovery Boiler
Total: 54,441
Cooling Facility/Cooling System
Balance of Plant
Civil/Buildings incl. On-Site Transportation 6,533
Engineering 2,510
Investment Costs
in T EUR
Electrical Equipment 4,932
I&C Equipment 1,332
13,317
729
5,893
Steam Turbine Package incl. Generator 9,805
615
Contractor's Soft Costs 8,752
Plant Startup
Table 6-25: Investment Costs of Gas-Based Generation Option 4
MALTA RESOURCES AUTHORITY
Energy Interconnection Europe - Malta March 2008
Final Report – Work Package IIA
LI 260442 Page 6-68
Year n-2 n-1 n
Disbursement in % 60% 40% Start Year
Table 6-26: Disbursement Schedule of Gas-Based Generation Option 4
The specific investment cost amounts to 472 EUR/kW, approximately 34% less compared to the
Gas-Based Generation option 1, 29% less compared to the gas-based generation option 2, and
respectively 14% less than the specific investment cost of supply option 3.
Figure 6-29 illustrates the investment break down. The dominating cost proportions are (i) the
heat recovery boiler; (ii) the steam turbine package; (iii) soft costs of the contractor and (iv) the
civil works.
18%
24%
1%
11%
9%
2%
12% 5%
1%
16%
Steam Turbine Package incl. Generator
Heat Recovery Boiler
Cooling Facility/Cooling System
Balance of Plant
Electrical Equipment
I&C Equipment
Civil/Buildings incl. On-Site Transportation
Engineering
Plant Startup
Contractor's Soft Costs
Figure 6-29: Investment Cost Break Down of Gas-Based Generation Option 4