IL PROGETTO EUROPEO CELSIUS

FOCUS SUL DIMOSTRATORE DI GENOVA

WASTE ENERGY RECOVERY FROM GAS EXPANSION IN URBAN NG NETWORKS

2017 Genoa’s Energy Vision – Le ultime iniziative del Comune in ambiente urbano

Ing. Roberto Milanesio

IRETI S.p.A. – IREN Group

2017 Genoa’s Energy Vision – Le ultime iniziative del Comune in ambiente urbano

Palazzo della Commenda

20 Giugno 2017

IREN GROUP

IREN was set up on 1st July 2010 through the merger of Enìa and Iride and is a leader in the Italian multi-

utilities business, a balanced mix of regulated activities and free activities and a strong integration

between upstream and downstream activities.

The IREN Group operates in the following sectors: electricity, gas, district heating, water service and

environment, and it also provides other public utility services (telecommunications, public lighting,

traffic light services, facility management).

Source: Company data

IRETI

IRETI is a subsidiary of Iren S.p.A.

IRETI is the Distribution Company for the gas network of Genoa city and 20 surrounding municipalities

• > 325,000 final customers

• 1,700 km of gas pipeline

(420 km in MP)

• 570 km2 covered area

Source: Company data

Progressive hydrocarbons phase out

Increase of the energy consumptions

Rational use of energy

CELSIUS Background

More effective use of energy through

ENERGY RECOVERY

EU and CELSIUS

• Co-funded by the EU 7th Framework Programme for Research and Innovation

• Budget: € 26.000.000

(EU contribution € 14.000.000)

• Duration: 57 months (2013-2017)

• 5 partner cities: • 5 partner cities:

– Gothenburg (lead partner)

– London

– Genoa

– Cologne

– Rotterdam

• > 50 Celsius Cities

Complex Complex Mediterranean High

GENOA characteristics

Complex territorial

morphology Urban areas are

concentratedalong the coast and two inland

valleys

Complex urban

texture

One of the biggest

historical centre in Europe

(UNESCO site)

Mediterranean

climate

Mild and short winters

High capillarity of

NG distribution

network

IRETI as Project Technical Partner

Genoa Municipality as the

Local Authority

CELSIUS Genoa Project Team

Local Authority

University of Genoa as the

R&D Partner

D’Appolonia S.p.A. as the

Local Coordinator to monitor&evaluateall CELSIUS demonstrators

District characteristics:

• Industrial, service and commercial end-users are within the District

• The area hosts the gate station of the natural gas distribution network, where

the gas pressure is reduced from transmission levels (24 bar) to distribution levels

(5 bar) and the gas flow is measured

• Gavette industrial site is managed by IREN and hosts the other companies of the

group IRETI, Iren Acqua, Iren Energia

CELSIUS GENOA Demo Project

Objective:

Development of a local energy generation and district heating network consisting

of:

• turbo-expansion process for natural gas to recover waste energy (converted to

electricity) from the gas expansion process

• new district heating and cooling network (micro-DHN) connected to a CHP

plant

Title

CELSIUS Demo Area

Gas pre-heatingHot water at 70°C

Hot water at 50°C

Gas from national transmission grid at 24 bar

Actual

heating

System

PAST

NOW

GENOA Demo Block Diagram

Turbo-expander

550 kWeElectric power

Gas to distribution network at 5 bar CHP

Electricity

Hot water at 50°C

Hot water at 70°C

Gas Distribution Network District Heating Network

Heat

Local Electricity Grid

Throttling

valves

NOW

What is turboexpansion

• Turboexpansion is the technology that performs the expansion of the gas

producing electrical energy by means of a turbine.

• Within CELSIUS project, IRETI has selected the use of a turboexpander for

natural gas decompression.

Ecological and cheap energy source

natural gas decompression.

• The Turboexpander reduces the gas pressure and produces electrical energy

recovering pressure waste energy.

• The supplier of Genoa Turboexpander has more then 25 years of experience in

the natural gas energy recovery.

• Natural gas is distributed at high pressure to minimize the losses, but the end

user need it at a lower pressure.

• Expansion turbines utilise the pressure drop to recovery the energy that

otherwise would be lost.

• The pressure reduction is usually obtained by a pilot-controlled pressure

regulator: the energy of the gas is thermally dissipated (Joule-Thomson

effect).

Operating principle

• With the use of an expansion turbine , the energy of the gas is transformed in

kinetic energy, and then in electrical energy in the generator.

Examples

Typical installation are in the local gas pressure reducing stations, where is

possible to recover from 160 to 3000 KW

Two possibility

Operating principle - Scheme

Blu: typical installation Red: recovery

Gas inlet Gas

outlet

24

bar

5

bar

2000 kW

160-

2000 kW

Turboexpander

G

The available potential energy may be calculated from the enthalpy difference between inlet and outlet of the turbine, multiplied for the mass flow.

Energy recovered (kJ/h) = Difference of enthalpy (kJ/kg) x Flow (kg/h)

Radial expansion turbine are designed for a high working range: the efficiency is high even at the lower loads.

The main contribution to the power is the flow of the turboexpander, but also a high enthalpy difference (high pressure drop) permit a significant energy

Operating principle - Theory

a high enthalpy difference (high pressure drop) permit a significant energy recovery.

Example

Inlet Temperature: 60 - 90 °C

Outlet Temperature: 0 - 10 °C

Inlet Pressure: 20 - 70 bar

Outlet Pressure: 5 - 10 bar

In the majority of the applications, the components (piping and valves) do not admit a outlet temperature of the turbine too low, the hydrocarbons that are present in the gas may condense if the gas become too cool. The best outlet temperature of the turbine is between 5 and 15 °C .

For this reason the gas must be preheated before the expansion.

The thermal energy that is needed for the preheating of the gas is transformed in the electrical energy produced.

Operation principle - Application

in the electrical energy produced.

Example

It is possible to use a cogeneration (production of heat and electrical energy). The burned gas also produces electricity, the total efficiency is higher than a conventional energy production.

If a free or a recovery thermal source is available it’s possible to increase the total efficiency of a NG turboexpansion plant.

Mandatory characteristics

• High Pressure NG that must be expanded at Low Pressure

• Availability of minimum gas flow during all the year

• Use of produced electrical energy in a local network or trade

it in the national grid

When a turboexpander can be used

it in the national grid

Favourable characteristic

• Possibility of using a free thermal source for gas preheating

Project timeline

Design phase (Apr 2013 – Apr 2015)

• Project Design Specifications and EPC contract EU tender

• Design of the TE, CHP and micro DHN (underground works and foundations)

• Civil works for preparing the area to install the equipment and the pipelines

• Authorizations procedures

Installation phase (May 2015 - Dec 2016)

• Finalization of the civil works

• Installation of TE, CHP and piping

Operation phase & Monitoring (from Jan 2017)

Environmental benefits

Lower direct emissions to the atmosphere with respect to the current situation will

be achieved. The project will make it possible to deliver both electricity and thermal

energy to external networks enabling savings of approx. 1200 ton CO2/year.

Technical KPIs

Environmental KPIs

Economic KPIs

Social KPIs

KPI List

Title

ID KPI

GE1T1

Ratio between the gas flow rate

through the turbo-expander and

the gas flow rate through the

lamination valve

GE1T2

Yearly amount of net electric

energy produced by the turbo-

expander

GE1T3

Yearly amount of net electric

energy produced by the CHP

system

GE1T4Total produced net electric

energy

GE1T5Yearly amount of thermal energy

ID KPI

GE1En1

Variation of emissions

for the main

considered pollutants

connected to the

electric energy

production compared

with the baseline

situation

GE1En2

Variation of emissions

for the main

considered pollutants

connected to the

ID KPI

GE1Ec1

Yearly savings

generated by self-

production of electric

energy with reference

to baseline situation;

GE1Ec2Yearly cost for natural

gas burnt in the CHP

GE1Ec3Yearly cost for natural

gas burnt in boilers

GE1Ec4

Savings arising from

the reduction of natural

ID KPI

GE1S1

Number of working

hours used for

running and

maintaining the TE-

CHP system

GE1S3

Number and type of

possible complaints

(e.g. for noise) by

the citizens living in

the neighbourhood

GE1S4

Number of additional

end-users benefitting

of the

implementation of

Technical KPIs Environmental KPIs Economic KPIs Social KPIs

GE1T5Yearly amount of thermal energy

produced by the CHP

GE1T6Yearly amount of thermal energy

provided by the district heating

GE1T7

Ratio between the yearly amount

of thermal energy used for gas

heating before the expansion in

turbine and the yearly amount of

thermal energy produced by the

CHP

GE1T8

Ratio between the yearly amount

of thermal energy provided by

the district heating network and

the yearly amount of thermal

energy produced by the CHP

GE1En2 connected to the

thermal energy

production compared

with the baseline

situation

GE1En3 Yearly GHG savings

gas consumption

GE1Ec5

Cost of maintenance of

the turbo-expander per

each kWh of net

produced electric

energy

GE1Ec6

Cost of maintenance of

the CHP per each kWh

of net produced

electric energy

GE1Ec7

Yearly cost of

maintenance of the

entire system

GE1Ec8

Variation in the bill for

end-users for thermal

energy consumption

implementation of

the new system

Technical data:

• Electric Power : 526 kWe CHP

550 kWe Turbo-Expander

• EE Production (estimated on 5.000 hours operating):

2.300 MWh per year (CHP)

2.800 MWh per year (TE)

Genoa Demonstrator - Results and Outlook

• Environmental Savings: 1.200 tons CO2 per year

Economics:

• Total investment cost : 3.021 €/000

• EU contribution: 1.497 €/000

Schedule

• Turboexpander and CHP commissioning completed in April 2017 - Turnover to

Operations is on going - Inauguration event on site at June 20

• Monitoring activities will continue for a full year up to the next winter season

providing the collected data to new SCIS (Smart Cities Information System)

platform

Performance

Genoa Demonstrator – Start-up highlights

Performance

• System fully compliant with the project requirements

• Thermal Power for gas pre-heating lower than expected

• Gas flow rate for maximum electrical power lower than expected

• Minimum operating gas flow rate for turboexpansion significantly lower than

expected

Potential of upgrading / replicability of the Genoa Demo

� Integration of the Genoa demonstrator with a natural gas station for

private and public vehicles and a public school located nearby

� Provide electrical supply

� Storage of mechanical energy through high pressure gas accumulation

� Use of return water of the DH network for intercooling process

Genoa Demonstrator – Further Expansion

� Use of return water of the DH network for intercooling process

� The extension of the project can reinforce the role of the Genoa

demonstrator as an example for further achievements in other cities,

aimed to a high replicability of the implemented solutions

Condensed Business Model: Partners&Benefits

Utility companySelf-production of electricity for

internal use. Additional clients.

Opportunity of recovering waste

energy.

Technology providersHigher penetration into the market &

development of new applications

Local AuthorityDevelopment of a

sustainable technology at

city level for energy

production with decreased

GHG emissions.

Connection of public

buildings with reduced

fees. Visibility for the city.

energy.

R&D PartnerOpportunities for creating

new SMEs (spin-off)

ConsultantSet-up and sell new services