CHP, thermal storage & thermal networks, and the interaction with the electric and gas grids. William D haeseleer KU Leuven Energy Institute Belgium

Transcription

1 CHP, thermal strage & thermal netwrks, and the interactin with the electric and gas grids. William D haeseleer KU Leuven Energy Institute Belgium

2 Philsphical Questin Why d we see a scietal tendency t mve twards decentralized/distributed generatin in electricity prvisin and a drive twards mre centralized appraches fr heat prvisin? Is there sme kind f idelgical agenda behind it?

3 Bundary Cnditins Thermal Netwrks The implementatin f thermal netwrks is very much dependent n the situatin and the cntext: the meterlgical circumstances, whether-r-nt there is already a heat netwrk present, the type f built envirnment, the availability f energy at lw marginal cst (such as e.g., gethermal heat, cheap waste heat frm the prcess industry f electrical pwer plants, smetimes superfluus electrical energy generated frm wind and/r PV slar), the existence f a well-distributed natural gas grid, etc. à f uttermst imprtance t determine the bundary cnditins befre ne can really start t deply thermal grids and their peratin.

4 Bundary Cnditins Thermal Netwrks Use f intelligent thermal netwrks is mre than just rdinary classical district heating, but a crrect estimatin f it must be embedded in a full system integratin apprach, hence including the thermal sectr, the electricity system (incrprating the grid) and the gas system (incrprating the grid). The business case ften depends n the cst f investment f the thermal grid itself and the vlume f heat ff take. The evaluatin f the heat grid strngly differs whether the investment csts have already been spent r nt in the past. It lks mre interesting t start frm already existing heat grids (because f the sunk csts ); But existing grid may be a disadvantage because mdern, mre intelligent thermal grids ffer mre pprtunities (such as heating and cling); Badly insulated huses vs zer energy buildings make a difference fr the heat demand

5 Bundary Cnditins Thermal Netwrks An imprtant aspect fr the implementatin f thermal netwrks is furthermre the transitin f e.g. gas-fired individual heating t a mre centralized philsphy. In this regard, als small micr CHP with lcal thermal strage, the future renewable methane (frm pwer-t-gas cnversin), must be cnsidered as pssible cmpeting technlgies. Als the temperature level f intelligent thermal netwrks must be integral part f this study fr bundary cnditins.

6 Bundary Cnditins Thermal Netwrks The market and ecnmic cntext will nt be negligible: Is there a liberalized market philsphy in existence with the authrities in a supervisry/regulatry rle? Or a fully regulated envirnment whereby the authrities basically d what they want? Optimally, all technlgies shuld be able t cmpete (cndensing bilers, lcal CHP, gas grids, heat pumps als fr cling, )

7 Furth Generatin Netwrks Ref: H. Lund et al, Energy, 2014

8 Static Evaluatin Energy Savings CHP Electrical efficiency CHP α E E& F& Thermal efficiency CHP α Q Q& F& 8

9 9? Q E E Q α α PVB F 1 0 η η = + > & Primary fuel saving f CHP with respect t separate prductin Evaluatin criteria CHP Primary Fuel Saving 1 Q E E Q PFS α α η η + = (7)

10 Evaluatin criteria CHP Primary Fuel Saving α? E αq PVB = F& + 1 > 0 ηe η Q Primary fuel saving f CHP with respect t separate prductin Imprtant aspects : - α E and α Q best nminal/rated efficiencies - which η E en η Q fr separate prductin? - Utilizatin duratin f the CHP need fr back-up el & heat - N heat t be cled away 10

11 Allcatin f Advantage t E Side Advantage savings t electrical side ften applied by service cmpanies used t supply heat wh nw install CHP t prduce and sell als electricity Take frm utset as basic hypthesis: α eff Q = η Q Example with gas engines as CHP: α α η η E Q E Q = 35% = 50% = 55% = 90% α eff Q eff = 90% & α = 79% E 11

12 Allcatin f Advantage t Q Side Advantage savings t thermal side ften applied by electric utilities used t supply electricity wh nw install CHP t prduce and sell als heat Take frm utset as basic hypthesis: α eff E = η E Example with CCGTs as CHP: α α E Q = 45% = 45% ηe = 55% η = 90% Q α eff Q = eff 248% & α = 55% E 12

13 Evaluatin criteria CHP System Apprach - Influence CCGT investment at increasing central elec demand (1) - Increase f demand fr electricity elektriciteitsvraag peak units piek-eenheden elektriciteitsvraag generatin shrtage prductietekrt demand increase Electric pwer demand cal steenkl CCGT nuclear STEG nucleair Electric pwer demand vraagstijging 13

14 Evaluatin criteria CHP System Apprach - Influence CCGT investment at increasing central elec demand (2) - Need fr extra generatin capacity elektriciteitsvraag generatin shrtage prductietekrt demand increase elektriciteitsvraag Assuming lw gas prices r high CO 2 penalty à cal abve gas in merit rder Electric pwer demand vraagstijging Electric pwer demand nieuwe STEG new CCGT 14

15 Evaluatin criteria CHP System Apprach - Dynamic aspects (1) - CCGT versus CHP with limited peratin time duratin elektriciteitsvraag Electric pwer demand nieuwe STEG new CCGT verdringing displacement elektriciteitsvraag Electric pwer demand CHP WKK slechts gedeeltelijke verdringing Only partial displacement! Less cal-fired PP pushed ut à less CO 2 avided

16 Evaluatin criteria CHP System Apprach - Dynamic aspects (2) - INDUSTRY 2000 à MW e extra CHP with α E =38%, α Q =42%, QI=14%, U=7500h/a STATIC Primary Energy Saving = 4000TJ i CO 2 -eq. reductin = 240 ktn CO 2 SIMULATION Primary Energy Saving = 4000TJ i CO 2 -eq. reductin = 250 ktn CO 2 INDUSTRY w/ extra CHP with 360 MW e extra CHP thermal CHP [GWh th ] bilers electric CHP [GWh e ] CCGTs Cal

17 Evaluatin criteria CHP System Apprach - Dynamic aspects (3) SPACE HEATING Simulatins Grey: Primary energy use CCGT biler Yellw: Electricity generatin CHP Central generatin back up Additinal heating Orange: heat generatin 17

18 Evaluatin criteria CHP System Apprach - Dynamic aspects (4), service & cmmercial sectr à MW e extra CHP with α E =35%, α Q =50%, QI=16%, U=4000h/a STATIC Primary Energy Saving = 2900TJ i CO 2 -eq. reductin = 170 ktn CO 2 SIMULATION Primary Energy Saving = 1800TJ i CO 2 -eq. reductin = 30 ktn CO 2 S & C Sectr w/ extra CHP with 360 MW e extra CHP thermal CHP [GWh th ] bilers electric CHP [GWh e ] CCGTs Cal

19 Typical Examples f District Heating Campus Luvain la Neuve grid length ~ 4 km heat lsses ~ 10% Originally 4 bilers then replaced by gas engines CHP Average perfrmance: 9.4 MW e ; 9.9 MW th α E =35%; α Q =36% Gas Engines Based: 4 1. Gas engines 3 x 3,3 MWth 2. Biler 5,8 MWth 3. Bilers 2 x 11,6 MWth 4. Heat Grid

20 Typical Examples f District Heating Campus Luvain la Neuve Static Evaluatin (as seen in LLN) Reference efficiency, η E = 55% (standard CCGT) and η Q = 90% Relative primary energy saving ~1.8% (incl grid lsses) Dynamic Evaluatin (generically fr cuntry ver 10 y) Lw gas prices Primary energy savings vary frm ~ - 5 PJ t 2 PJ Avided CO 2 emissins vary frm ~ ktn t 110 ktn High gas prices Primary energy savings vary frm ~ - 6 PJ t 1 PJ Avided CO 2 emissins vary frm ~ ktn t 80 ktn

21 Typical Examples f District Heating Gent Belgium grid length ~ 10 km heat lsses ~ 10% Max elec gen mde: 51.2 MW e ; 9.1 MW th α E =50.7%; α Q =8.8% 3 Max heat gen mde: CCGT-based 46.2 MW e ; 27.4 MW th α E =45.2%; α Q =26.8% Gas turbine 2. Recvery Biler 3. Extra Heat Recvery Bundle 4. Steam Turbine 5. LP-steam bleeding 6. HP-steam bleeding 7. Cndensr 8. Heat Grid 8

22 Typical Examples f District Heating Gent Belgium Static Evaluatin (as seen in Gent) At time f investment decisin Gent η E = 48% and η Q = 90% Relative primary energy saving ~9.4% Dynamic Evaluatin (generically fr cuntry ver 10 y) Lw gas prices Primary energy savings vary frm ~ 1 PJ t 5 PJ Avided CO 2 emissins vary frm ~ - 40 ktn t 330 ktn High gas prices Primary energy savings vary frm ~ 0.6 PJ t 3.2 PJ Avided CO 2 emissins vary frm ~ 110 ktn t 200 ktn

23 Impact CHP n Gas at Distributin Level

24 Impact CHP n Gas at Distributin Level

25 Impact CHP n Gas at Distributin Level R HE = Heat/Electricity rati RSC = Relative Strage Capacity Ref: J. Vandewalle, 2014

26 Impact CHP n Gas at Distributin Level R HE = Heat/Electricity rati RSC = Relative Strage Capacity Ref: J. Vandewalle, 2014

27 Impact CHP n Gas at Distributin Level R HE = Heat/Electricity rati RSC = Relative Strage Capacity Ref: J. Vandewalle, 2014

28 Impact CHP n Gas at Distributin Level Heat Led (HL): CHP nly n when Q CHP is sent t custmer r t strage tank Ecnmically Led (EC): mst ecnmic peratin depending n elec and gas prices R HE = Heat/Electricity rati RSC = Relative Strage Capacity Ref: J. Vandewalle, 2014

29 Cnclusins Bundary cnditins f thermal netwrks imprtant Full system integratin needed Heating-purpse sectr Electricity system Natural gas system Optimal slutin where all technlgies can freely cmpete, if all are penalized fr external csts

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