Fuel cells and electrolysers in future energy systems - VBN

More documents

Recommendations

Info

8 Results of the analyses of ancillary service designs The analyses of the four ancillary service scenarios are performed for the three different energy systems de‐ scribed. The scenarios are analysed through two types of diagrams, by which the importance of the ancillary service design can be compared in the different energy systems. The first diagram illustrates the annual excess electricity production in TWh, as a function of renewable en‐ ergy input in an open energy system. In the open system, CHP plants with heat storages and, if present, heat pumps and flexible electricity demands are used to balance heat and electricity demand during the given hours and with the aim of minimising excess electricity production. The energy system analyses are per‐ formed with due consideration for the different ancillary service designs, which restrict the operation possi‐ bilities of the plants involved. Hence, the ability of the system to reduce excess electricity production also depends on the restrictions made in relation to ancillary services. In this energy system analysis, a low excess electricity production represents a good ability of the system to integrate fluctuating renewable energy sources. The second type of diagram illustrates annual fossil and/or biomass fuel consumption in TWh in a closed en‐ ergy system excluding renewable energy sources, in this case wind power. In the closed system, the same regulation applies as above. However, the following strategy for handling excess wind power production is used: First, CHP production is replaced by boilers in the district heating systems and then wind turbines are stopped. When fuel consumption is lowered, the energy system is able to efficiently utilise intermittent re‐ newable energy sources. In both diagrams, the production from wind turbines varies between 0 to 100 per cent of the electricity de‐ mand in the three energy systems analysed. In the analyses of the IDA 2030 and the IDA 2050 energy systems, other intermittent renewable resources have been removed. In fig. 6, the results of the analyses are presented. The effects of replacing CCGT and SCGT with SOFC in the energy systems are also illustrated. On the left side of fig. 6, the excess electricity diagram is presented. The first step in the task of integrating renewable energy is to enable CHP plants to produce electricity, independ‐ ently of the momentary heat demand, by using heat storages. Excess electricity does not decrease when changing from gas and steam turbines to fuel cells in the current top‐down control of the ancillary service supply. When enabling the local SOFC CHP plants to take part in grid stabilisation, fuel savings of between 0.5 and 1 TWh are achieved in the BAU 2030 energy system. In the two renewable energy systems, IDA 2030 and IDA 2050, the ability to reduce excess electricity production is lower than in the BAU 2030 energy system when enabling the local SOFC CHP plants to take part in grid stabilisa‐ tion. This is due to the fact that other flexible technologies form part of these energy systems, such as heat pumps and flexible demand, which make it possible to integrate more wind power than in the BAU 2030 en‐ ergy system. In the situation in which 50 per cent of the offshore wind turbines are able to assist in the grid stabilisation task, all three energy systems experience large reductions in excess electricity production. In the fourth sce‐ nario, in which the 450 MW minimum production at central plants is replaced by SOFC on standby, excess electricity production is further decreased. The importance SOFC on standby increases as the amount of wind increases. On the right side of fig. 6, annual fuel consumption excluding renewable energy sources is illustrated. As ex‐ pected, fuel consumption decreases, as the ability of the energy system to integrate excess electricity is im‐ proved. In the renewable energy systems, the replacement of gas and steam turbines is especially important to the reduction of fuel consumption. Fuel cells are more important in future renewable energy systems than in the BAU systems. Even with more than 50 per cent wind power production in the renewable energy sys‐ tems, they enable a decrease in fuel consumption of 2 to 2.5 TWh. 40
In the first ancillary service scenario, in which local SOFC CHPs participate in grid stabilisation, fuel consump‐ tion is marginally reduced. Again, when wind power also contributes to the supply of ancillary services, fuel consumption decreases significantly. With a wind power share of more than 50 per cent, the integration of standby SOFC further decreases fuel consumption. In the renewable energy systems, the other components installed also reduce fuel consumption by replacing boiler production at CHP plants with large heat pumps and by using flexible demands. Such demands are placed in situations with high shares of wind power. In these systems, the operation hours of SOFC CHP de‐ crease, as a higher share of the electricity demand is met by renewable energy and a higher share of the heat demand is met by heat pumps. In the IDA 2030 energy system, 21.5 TWh of intermittent renewable energy is proposed. In this situation, the SOFC CHP must participate in the grid stabilisation task in order to avoid excess electricity production. In the 100 per cent renewable energy system, IDA 2050, 38.8 TWh of intermittent renewable energy is installed; hence, the flexibility of SOFC is also important in this system. The potential flexibility in the operation of SOFC, which improves the efficiency by replacing gas and steam turbines and participating in grid stabilisation, is important in renewable energy systems because biomass‐derived fuels constitute a limited resource. In the BAU 2030 projection from the Danish Energy Authority, 14.9 TWh of electricity is produced from onshore and offshore wind turbines. In such a situation, local SOFC CHP participating in grid stabilisation would improve fuel efficiency and improve the integration of installed wind power. The fast start‐up and the good regulation abilities of SOFCs are important measures in future energy systems, since they improve the ability of the systems to integrate renewable energy and reduce fuel consumption. Base load plants are not needed in future renewable energy systems. Even if all offshore wind turbines were able to provide ancillary services, instead of the 50 per cent shown in the analyses in Fig. 6, the performance of offshore wind turbines participating in grid stabilisation would not improve. Similar analyses have been conducted, in which wind power is additional to the intermittent renew‐ able resources already installed, i.e. wave power and photovoltaic power in the two renewable energy sys‐ tems. This does not change the results presented here, either. 41
Page 1:
Fuel cells and electrolysers in fut
Page 5 and 6:
Tilegnet mine forældre Karl Kristi
Page 7 and 8:
Abstract Efficient fuel cells and e
Page 9 and 10:
Dansk resumé Effektive brændselsc
Page 11 and 12:
Contents ABSTRACT .................
Page 13:
Appendices I. B. V. Mathiesen and M
Page 16 and 17:
In this dissertation, fuel cells an
Page 18 and 19:
Nomenclature Power generation and r
Page 20 and 21:
Fuel cells and electrolysers have t
Page 22 and 23:
In December 2006, a plan for how an
Page 24 and 25:
a) Fuel 107 units b) Fuel 87 units
Page 26 and 27:
In the current energy system, elect
Page 29 and 30:
2 The energy system analysis method
Page 31 and 32:
taxes. Output consists of annual en
Page 33 and 34:
3 Reference systems and the design
Page 35 and 36:
the IDA 2030 system, and, in an upd
Page 37:
gies to improve the integration of
Page 40 and 41:
Fuel cells AFC PEMFC PAFC MCFC SOFC
Page 42 and 43:
PEMFCs are characterised by a rathe
Page 44 and 45:
tion time in portable devices [25].
Page 46 and 47:
Except when pure hydrogen is used,
Page 48 and 49:
they supply. In transport applicati
Page 50 and 51:
Thus, when in operation, all types
Page 52 and 53:
CHP, and under four ancillary servi
Page 54 and 55:
Grid‐stabilising plants 30 per ce
Page 56 and 57:
In the IDA 2030 energy system, a sh
Page 58 and 59:
PES excl. wind power (TWh) PES excl
Page 61 and 62:
6 Applications of solid oxide fuel
Page 63 and 64:
tion of power plants and improve th
Page 65 and 66:
hydrogen Central and Local FC‐CHP
Page 67 and 68:
The combinations of seven different
Page 69 and 70:
when fuel prices are high, especial
Page 71 and 72:
6.4 Socio‐economic consequences I
Page 73 and 74:
7 Individual household heating syst
Page 75 and 76:
kW/kW‐average 3 2 1 0 Heat Demand
Page 77 and 78:
Fig. 19, Annual fuel consumption of
Page 79 and 80:
Fuel (TWh/year) 14 12 10 8 6 4 2 0
Page 81 and 82:
M. EUR/year 800 700 600 500 400 300
Page 83 and 84:
Fuel (TWh/year) 18 16 14 12 10 8 6
Page 85 and 86:
d) Compared with other fossil fuel
Page 87 and 88:
systems are installed, such low tax
Page 89:
given heat production. A system is
Page 92 and 93:
energy systems in the coming years,
Page 94 and 95:
The second of the two types of ener
Page 96 and 97:
Wind power Fuel Power plant CHP Boi
Page 98 and 99:
has been used for identifying the n
Page 100 and 101:
In Fig. 37, the effects of using th
Page 102 and 103:
In the energy system analyses, HP p
Page 104 and 105:
M€/TWh fuel saved 120 100 80 60 4
Page 106 and 107:
For all alternatives, doubling the
Page 109 and 110:
9 Life cycle screening of solid oxi
Page 111 and 112:
chromium alloy used in the intercon
Page 113: In terms of primary energy consumpt
Page 116 and 117: ures on the path towards future 100
Page 118 and 119: plemented first. The socio‐econom
Page 120 and 121: socio‐economic calculations)," Da
Page 122 and 123: [40] M. C. Tucker, G. Y. Lau, C. P.
Page 124 and 125: [69] H. Lund, "Excess electricity d
Page 127: Appendix I 3
Page 130 and 131: 2 Fuel cell types In most countries
Page 132 and 133: transport or smaller devices. DMFCs
Page 134 and 135: combined with the water management
Page 136 and 137: While interconnectors diffuse the g
Page 138 and 139: the systems are less sensitive to p
Page 140 and 141: Annex I. AFC Technology (2008‐pri
Page 142 and 143: Annex III. LT‐PEMFC Technology (2
Page 144 and 145: Annex V. MCFC Technology MCFC‐sys
Page 146 and 147: References [1] B. V. Mathiesen and
Page 148 and 149: [32] J. R. Selman, "Molten‐salt f
Page 150 and 151: [64] L. Blum, H. P. Buchkremer, S.
Page 153 and 154: Abstract Solid oxide fuel cells and
Page 155 and 156: West Denmark Norway Germany 31 Swed
Page 157 and 158: 2 Ancillary service requirements An
Page 159 and 160: have been identified. For SOFCs, me
Page 161 and 162: As a reference for the analyses, a
Page 163: • Wind turbines and locally dispa
Page 167 and 168: 10 Acknowledgements This paper is p
Page 169: [34] M. C. Tucker, G. Y. Lau, C. P.
Page 173 and 174: Research Signpost 37/661 (2), Fort
Page 175 and 176: Energy system analysis of fuel cell
Page 189: Energy system analysis of fuel cell
Page 193 and 194: Solid oxide fuel cells in renewable
Page 195 and 196: now, the changes in the Danish ener
Page 197 and 198: In the next step, a market exchange
Page 199 and 200: Extensive investments have to be ma
Page 201 and 202: 2.4 Costs of fuels, fuel handling,
Page 203 and 204: Input: BAU 2030 Electricity system
Page 205 and 206: potential for producing heat in FC
Page 207 and 208: cies do not increase due to larger
Page 209 and 210: In dry years, FC‐CHPs generate pr
Page 211 and 212: 4 Conclusion SOFC can improve the f
Page 213: [23] Danish Energy Authority, "Frem
Page 217 and 218:
Comparative energy system analysis
Page 219 and 220:
2 Methodology In the methodology, t
Page 221 and 222:
to fuel at households of 72 per cen
Page 223 and 224:
listed in table 5 are from the Dani
Page 225 and 226:
Fig. 4, Annual fuel consumption of
Page 227 and 228:
enables a heat supply for at least
Page 229 and 230:
The COP of both HP systems have to
Page 231 and 232:
operated simultaneously; that the C
Page 233 and 234:
The HP systems analysed for 300,000
Page 235 and 236:
M. EUR/year 1,300 1,100 900 700 500
Page 237:
[11] B. V. Mathiesen and H. Lund, "
Page 241 and 242:
Comparative analyses of seven techn
Page 243 and 244:
energy system analysed. Outputs are
Page 245 and 246:
illustrates the excess electricity
Page 247 and 248:
Input: DEA 2030 (market) 123 Refere
Page 249 and 250:
Wind power Fuel Power plant CHP Boi
Page 251 and 252:
of driving at full capacity. The di
Page 253 and 254:
Open energy system, 25 TWh annual w
Page 255 and 256:
Marginal PES excl. wind (TWh) 0,0 -
Page 257 and 258:
educes excess production and fuel s
Page 259 and 260:
M€/TWh fuel saved 120 100 80 60 4
Page 261 and 262:
[8] M. Little, M. Thomson, and D. I
Page 263:
[37] Danish Energy Authority, Elkra
Page 267 and 268:
Long term perspective for balancing
Page 269 and 270:
Contents 1 Technology Description .
Page 271 and 272:
7.2.1 Fuel cell types In Table 7-2
Page 273 and 274:
In the SOFCs the electrolyte allows
Page 275 and 276:
In the same energy system SOFC CHP
Page 277 and 278:
400$/kW before 2015 also for SOFC s
Page 279 and 280:
unning temperature is lowered to 55
Page 281:
[12] B. V. Mathiesen and H. Lund, "
Page 285 and 286:
Abstract Integrated transport and r
Page 287 and 288:
phase. The detailed energy system a
Page 289 and 290:
The increase in the international a
Page 291 and 292:
2030, this results in 28.56 PJ net
Page 293 and 294:
ate to 6 per cent. The result is th
Page 295:
Appendix IX 171
Page 298 and 299:
2 The design of 100% renewable ener
Page 300 and 301:
4 documentation of the model can be
Page 302 and 303:
6 1.000 900 800 700 600 500 400 300
Page 304 and 305:
8 combined in order to reach the ta
Page 307 and 308:
Uncertainties related to the identi
Page 309 and 310:
tion of one marginal technology is
Page 311 and 312:
policies for changes and a projecti
Page 313 and 314:
The policy from 1996 [24] built on
Page 315 and 316:
tial LCA studies should include sev
Page 317 and 318:
6 Case study of the affected electr
Page 319 and 320:
adding waste to the BAU energy syst
Page 321 and 322:
fected; thus, reinvestments are aff
Page 323 and 324:
Appendix A LCA‐Study Miljømæssi
Page 325:
LCA‐Study LCA of Danish fish prod
Page 328 and 329:
[16] G. Finnveden, J. Johansson, P.
Page 330:
[46] N. Mattsson, T. Unger, and T.
show all

Fuel cells and electrolysers in future energy systems - VBN

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?