Literature (Total Energy System)

8/7/2019 Literature (Total Energy System)

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Akademin fr hllbar samhlls- och teknikutveckling

REPORT

Vsters, den 13 December. 2010

Thermal Engineering

Literature Review

Total Energy System

Projektarbete utfrt av group 4: Teacher: Jan Sandberg

Photchara, WER015, [email protected]

Sarut, WER015, [email protected]


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Total Energy System 2010

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Abstract

In many countries of the world, the ability supply electricity, heating and cooling load to

urban area is essential. Especially, the completely reducing or avoid using fossil fuel

combustion to product sustainable heat and electricity. This literature compares technologies

that use for small scale heat and power production in term of energy efficiency, environmentissues, and economic. These technologies and government policy would be work together to

increase potential of energy production.


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Table of Contents

Abstract ...................................................................................................................................... 0Table of Figure ........................................................................................................................... 3Introduction ................................................................................................................................ 4Purpose of Literature .................................................................................................................. 4Report structure .......................................................................................................................... 4Energy loss in transmission ........................................................................................................ 5

Heat transmission loss ............................................................................................................ 5Electricity transmission losses ............................................................................................... 5

Electricity and heat Generation .................................................................................................. 6Combine heat and power (CHP) ............................................................................................ 6District Heating of Buildings ................................................................................................. 7New CHP Power Plant ........................................................................................................... 7Biomass .................................................................................................................................. 7

Small scale heat and power production ...................................................................................... 8Decentralization of Energy Production .................................................................................. 8Hybrid Energy System ........................................................................................................... 8Economic ................................................................................................................................ 9Environment Issue .................................................................................................................. 9

Conclusion ................................................................................................................................ 10Appendix A District heating usage in 2009 ............................................................................. 11References ................................................................................................................................ 13


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Table of Figure

Figure 1 District heating and transmission losses ...................................................................... 5Figure 2 Electricity and transmission losses .............................................................................. 5Figure 3 Separate and combine heat and power comparison ..................................................... 6Figure 4 Diagram of the house station ....................................................................................... 7Figure 5 Economical comparison: diesel vs. hybrid system (life cycle costs) ........................... 8Table 1 Energy consumption and production in Buller Inland, Sweden ................................. 9Table 2 Standard result summary table ...................................................................................... 9Table 3 Technology comparisons ............................................................................................ 10


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Introduction

Present time, most of human activities cannot be operated without energy, for example

transportation, industry, working, and heating. Apparently energy becomes a big part of our

life. Furthermore the official long terms of government goal is convert current energy

production to renewable energy at least 50 percent, increase energy efficient use 20 percentand reduces green house gas emissions 40 percent. Nowadays there are many technologies are

being used to produce the energy, wind turbine, solar cell, coal, and biomass power plant for

example. To choose appropriate energy power technology, many factors are taken in

consideration such as city size, climate, population density, fuel source, economic, energy

policy, and environment impact. In some cases education is the key factor which has to be

concerned. In higher level some energy management methods are used to improve energy

production.

Purpose of Literature

This literature focuses on Total Energy System, its shape, future situation and policy in some

countries which applies technology with energy most suitably. Why is small scale heat and

power generation (CHP) technology the best solution? Economic analysis and CO2 emission

perspectives are also included in this literature.

Report structure

This report is structured as follow:

Section 1: Introduction

Section 2: The concept of small scale CHP and DH

Section 3: Conclusion and recommendation


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Energy loss in transmission

Heat transmission loss

Figure 1 District heating and transmission losses

Sources: SCB, 2009

As illustrated in Figure 1, the transmission losses are the main loss of Sweden DH [1]. The

total losses in DH network increase with increasing the supply water temperature. Moreover

losses during heat transfer can be reduced, by reducing electrical energy during hot water

transportation to consumers and by reducing heat loss in pipelines due to the water flow ratein system increase, when water supply temperature reduce, resulting in higher cost of

pumping. For this reason heat losses should be reduce by reducing transmission distance

between heat supply and consumers [2].

Electricity transmission losses

Figure 2 Electricity and transmission losses

Sources: SVENSK energy, 2009

Transmis

sion

losses 8%

(6 116

GWh)

Deliveries

of DH

92% (66

261

GWh)

Transmission

losses 10,2%

Deliveries of

Electricity

89,8%


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In 2009, total electricity consumption including transmission losses, large electric boilers in

industries and heating plants amounted to preliminary 138,4 Twh [3] The loss of energy in

transmission is main associated to distance of transmission. Figure 2 shows the proportional

between electrical transmission loss and total energy production.

Electricity and heat Generation

Combine heat and power (CHP)

CHP, widely recognized as a highly efficient energy conversion technique, is technology that

can be generating both usable heat and electrical power in single process. CHP systems are

attractive because they emit less CO2 than separate heat and electricity production. Figure 3

shown comparisons between separation of heat and electricity and CPH in term of energy

production and CO2 emission [4]. The CPH capacity required for small scale is between 1-30MW.

Figure 3 Separate and combine heat and power comparison

Sources: IEA/OECD, 2009

55 electricity

115 fuel

50 electricity

100 fuel

80 heat 50 electricity 80 heat

170 fuel

215 fuel

31 units CO221 units CO2 18 units CO239 units CO2

Central thermal

power plant

Industrial steam

boiler plant

Industrial CHP

plant

Separate production of heat and electricity

(natural gas)

Combine heat and power

(natural gas)


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District Heating of Buildings

Figure 4 Diagram of the house station

Source: Energy and Buildings, 2004

Combination a district heating with individual heat pumps in the buildings is the best solution

for substitute tradition heat generator for example gas or oil boilers to reduce CO 2 emission

and gain more efficient individual heat sources [5]. The principle diagram of the house hot

water station is shown in Figure 3 [6].

New CHP Power Plant

CHP is stand for Combine Heat and Power the plant has generate both electricity and heatpower instead of rejecting the waste heat to atmosphere. This development has increased up

overall efficiency of hold system almost a half of old one, Conventional Generation [7]. More

efficiency means that fuel consumption is reduced, green house gases emission are also

reduced. Sometime instead of heat generation cooling load is produced in hot country. In

Suvarnabhumi, Thailand use combine cooling and power technologies to generate both power

and cooling load for Suvarnabhumi Airport [8].

Biomass

CHP system can use many of fuel sources there are natural gas, biomass, coal, biogas and fuel

oil. Due to the green house effect renewable energy source, biomass for this case is widely

used as fuel in CHP power plant [9]. The biomass fuel has lower energy density comparing to

other fossil fuel, that mean large of fuels are transported from the fuel source to the plant site.

To reduce which cost capacity CHP power plant are reduced to smaller scale and construct in

rural area that have high fuel resource [10].

Hot Water Heat

Exchanger

Heat

ExchangerExpansion tank

DH

Meter

Hot water tank

Circulation pump Space heatingDistrict heating

Cold water


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Small scale heat and power production

Decentralization of Energy Production

In Sweden, Residential and commercial heat used for space heating of buildings and sanitary

hot water in Sweden is distributed from centrally heat generation. However efficient way totake more advantage of waste energy is Decentralized Energy System this can increase

more efficiency and reduce carbon emission from the total energy system [11]. The

decentralized energy system is to make a new energy network with many sub-small heat and

power plant. All sub-small plant is spread located inside city or rural then all of energy

production are connect to network grid, this decrease energy transmission distance from plant

to consumer the transmission loss is reduced. In additional about decentralized energy system,

when energy demands of some consumers are increased they can directly use the energy from

other lower energy demand [12]. There is a paper name An Integrated method for

Decentralized Combined Heat and Power Planning show result in Iran next 25 years, theenergy loss will be reduced from 20 to 8 % and 30 % of pollutant emission will be reduced

from decentralized generation technologies [13].

Hybrid Energy System

To transmit the energy power to really far away rural, there are a lot of grid extension costs.

The batter way to avoid this cost is to use a hybrid energy system (sometime called Energy

Decentralized), use both renewable energy source (free and clean energy but less

sustainability) and non-renewable energy source (cheap energy and more sustainability). The

system can solve both economic and pollution emission in the rural area. The paper name

Hybrid power systems based on renewable energies shows economical comparison of dieseland hybrid system in Tanzania and India [14]. Both countries use photovoltaic/diesel hybrid

system.

Figure 5 Economical comparison: diesel vs. hybrid system (life cycle costs)

Source: Trama Tecno Amblental S.L.


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Sometime hybrid energy system use combination of renewable energy source. In Buller

Island, Sweden use PV-Wind Hybrid system, the energy production for the system enough for

the city and construction cost was a half of sea cable installation to the grid. Table below

energy production and consumption from year 1997 to 1999 in Buller Island, Sweden [15].

Summary of accumulated energy in Ampere hours (Ah) at 48V, 1997-99

PV Wind Back-up Total Consumption

(Ah) (Ah) (Ah) (Ah) (Ah)

1997 15 099,7 3 936,9 1 804,0 20 840,6 18 643,4

1998 11 175,0 4 212,0 1 188,0 16 575,0 15 867,0

1999 13 754,5 4 093,0 766,0 18 613,5 17 873,0

Table 1 Energy consumption and production in Buller Inland, Sweden

Source: CADDET, 2001

Energy optimization is also worked to minimize the energy production cost in hybrid energy

system. The paper name Performance-Objective Design of a Wind-Diesel Hybrid Energy

System for Scott Base, Antarctica shows how to optimize the hybrid energy system in Scott

Base [16]. Fuel saving and payback period are shown in Table 2.

Model

Northwind

Wind

Turbine

(100MW)

Enercon

Wind

Turbine

(330MW)

Fuel consumption Predicted

yearly fuel

savings

(liter)

Payback

period

(year)Total Generator Boiler

1 1 331151 274 731 56 420 61 441 13,52 2 295556 255 028 40 528 97 036 17,1

3 3 270064 237 216 32 848 122 528 20,3

4 1 219907 191 750 28 157 172 685 7,9

5 2 154766 133 924 20 842 237 826 11,4

Table 2 Standard result summary table

Source: Performance-Objective Design of a Wind-Diesel Hybrid Energy System for Scott Base, Antarctica

Economic

In case of economic viewpoint small-decentralized CHP system is the efficient way to investaccording to increasing of efficiency, fuel price, and life-cycle costs [17]. The paper name

Small Cogeneration by Biomass Gasification on the Decentralized Energy Production

shows energy economic analysis of some small hotel in Portugal, the payback period for

wood chips CHP system is 3.14 and 4.86 years [18]. In additional Photovoltaic/Biomass CHP

Hybrid System was use in the paper; this is the efficient way to increase flexibility of energy

production due to energy demand.

Environment Issue

The environment issues associated with Sweden government policy to reduce at least 40

percent green house gases emissions in 2020 [19]. Energy supply and conversion have impactto environment because energy production process emits greenhouse gases to environment.


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Fuel burning releases rise to emissions of substances for example NOX and SOX [3]. Moreover

transmission or distribution of energy affects the environment in direct and indirect ways.

Directly, through using resources in construction, operation and grid maintenance for example

green house gases emission from fuel combustion processes; and indirectly, through grid

losses during distribution [20]. The importance factor for develop sustainable energy andefficient method to reduce greenhouse gases emission is using CHP to generate heat and

power [21].

Conclusion

In this study explores how to produce that and power in small scale instead large scale system.

Our approach involves literature review of heat and electric energy production and

distribution to consumers. The CHP is widely used to produce heat and power because they

have potential to produce high energy efficiency than separate production and prevent

significant CO2 emissions through the benefits of distributed. The decentralization concept is

important methodology to produce energy in small scale because of uses less transmission

media than traditional effect to raise more efficiency as shown in Table 3. While hybrid

system is the best way to support Swedish aim to increase renewable energy production.

Efficiency Environment Economic

CHP Reduce loss fromseparate production ofheat and electricity

Reduce emission greenhouse gases

Increase productionfrom heat andelectricity

Decentralize Reduce transmissionloss

Reduce land use Sell surplus electricityto the grid

Hybrid system - Reduce non renewableenergy use

Reduce long termvariable cost

Table 3 Technology comparisons

In summarize combination of CHP, decentralization and hybrid system approach are the

effective energy management method that use for shift up energy efficiency and reduce

greenhouse gases emissions of the total energy production or system. In additional both

methods are suitable to operate on small scale system. However energy market is

unpredictable, energy optimization and sensitivity analysis are higher solution to improve thesensitivity of the system.


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Appendix A District heating usage in 2009


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CHP-plantsHeat only

plants TotalGWh GWh GWh

Production and deliveries of distric heatHeat production from fuel: 29 607 13 663 43 270

CHP 23 102 - 23 102 Heat only 6 505 13 663 20 168

Flue gas condensing 2 917 785 3 702Electric boilers 81 95 176Heat pumps 1 510 3 913 5 423

Total production 34 115 18 456 52 571

Received heat out of the branch 1 056 2 036 3 092

Received heat from the plants within thbranch 2 136 14 578 16 714

Total turnover 37 307 35 070 72 377

Transmission losses 3 070 3 046 6 116Deliveries of district heating 34 235 32 024 66 259

Use of electric energy and fuel

Use of electricity 1 804 1 908 3 712 For fuel based heat production and

pumping 1 380 691 2 071 Electric boilers 85 97 182 Heat pumps 339 1 120 1 459

Use of fuels 36 842 15 252 52 094 CHP-production 27 409 15 252 42 661 Other fuel based heat only

production 9 433 - 9 433

% Efficiency CHP 84,3 - 84,3% Efficiency heat only 69,0 89,4 81,6

Sources: SCB, 2009.


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References

[1] Statistics Sweden. Electricity supply, district heating and supply of natural and

gasworks gas 2009. 2009. .

[2] Comakl K, Yksel B, Comakl . Evaluation of energy and exergy losses in district

heating network. Applied thermal engineering 2004, 24(1): 1009-1017.

[3] Svensk energy, The electricity year 2009. 2009. .

[4] International Energy Agency, Cogeneration and district energy. 2009. .

[5] Lund H, Mller B, Mathiesen BV, Dyrelund A. The role of district heating in future

renewable energy systems. Energy 2010; 35(1): 1381-1390.

[6] Bhm B, Danig PO. Monitoring the energy consumption in a district heated

apartment building in Copenhagen, with specific interest in the thermodynamic

performance. Energy and buildings 2004; 36(1): 229-236.

[7] Available in: http://www.epa.gov/chp/basic/efficiency.html, Efficiency Benefits.

[8] Available in: http://www.dcap.co.th/Default.aspx?pageid=20, District Cooling

System and Power plant (DCAP).

[9] Available in: Vetenskapligt underlag fr klimatpolitiken, Miljvrdsberedningen,

Miljdepartementet; 2007. Report No.: ISSN 1653-2570.

[10] Available in: http://www.ucsusa.org/clean_energy/technology_and_impacts/

energy_technologies/how-biomass-energy-works.html, How Biomass Energy works.[11] Available in: http://www.greenpeace.org.uk/blog/climate/decentralised-energy-w,

Decentralized Energy.

[12] Available in: http://www.dreamingnewmexico.org/energy/distribution, Distribution.

[13] Available in: An Integrated method for Decentralized Combine Heat and Power

planning, by Seyed Mohammad.

[14] Available in: Hybrid power systems based on renewable energies.

[15] Available in: A PV-Wind Hybrid System on Buller Island, Sweden.

[16] Available in: Performance-Objective Design of a Wind-Diesel Hybrid Energy

System for Scott Base, Antarctica, by Jake A. Frye, University of Canterbury, 2006.[17] Available in: http://www.ecogeneration.com/, Reduced energy costs

[18] Available in: Small Cogeneration by Biomass Gasification on the Decentralized

Energy Production, by J. Galvo, S. Leito, S. Malheiro, T. Gaio

[19] Sweden energy agency. Energy in Sweden 2009. 2009. < http://213.115.22.116/

System/ViewResource.aspx?p=Energimyndigheten&rl=default:/Resources/

Permanent/Static/ab6822c96d86401c8d2a5e362bdfa0d7/ET2009_30.pdf>

[20] Vattenfall AB, Life-cycle assessment Vattenfalls electricity in Sweden. 2005.

.


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[21] Dzenajaviciene EF, Kveselis V, Kveselis C, Tamonis M. Economic analysis of the

renovation of small-scale district heating Systems - 4 Lithuanian case studies. Energy

Policy 2007; 35(1): 2569-2578.

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Literature (Total Energy System)