Industrial application of SOFC systems in waste water treatment plants Business case

Transcription

1 Industrial application of SOFC systems in waste water treatment plants Business case Adam Hawkes Sara Giarola Gbemi Oluleye Imperial College London

2 SOFCs: pros and cons High electrical efficiency Low emissions Reduced energy security concerns and impact on use of natural resources (virtually zero if fuelled with a waste such as biogas) Flexibility of fuels High costs High frequency of stack replacement Low technology lifetime electricity biogas heat 2

3 Outline SOFC: current and projected costs The case study of Collegno (economic and technical feasibility) Market potential in WWTPs in Europe (estimate: optimisation and generalization) 3

4 Technological learning Roland Berger, Advancing Europe s energy systems: Stationary fuel cells in distributed generation. Cumulative production - As is 100 1,000 10,000 Capital cost Module [ /kw] 16,280 8,303 3,346 2,077 Maintenance [ /kw/y] Module lifetime (stack ex.) y Stack lifetime y % capital cost reduction - 68% capital cost reduction 4

5 Technological learning Roland Berger, Advancing Europe s energy systems: Stationary fuel cells in distributed generation. Cumulative production - As is 100 1,000 10,000 Capital cost Module [ /kw] 16,280 8,303 3,346 2,077 Maintenance [ /kw/y] Module lifetime (stack ex.) y Stack lifetime y % capital cost reduction - 68% capital cost reduction 5

6 Costs and performance SOFC vs state-of-the art technologies (reference size 50 kw) Variables SOFC MGT ICE Th. efficiency 27 % 43 % 60 % El. efficiency 54 % 27 % 28 % Module lifetime, y Stack lifetime, y Unit CAPEX, /kw 8,303 2,820 2,597 Replacement, /kw 1,223 N.A. N.A. Maintenance ( /kw/y) Clean-up unit CAPEX, /kw/y 917 N.A. N.A. Clean-up unit OPEX, /kw 76 N.A. N.A. 6

7 Collegno WWTP: optimal SOFC dispatch Biogas composition, % CH 4 65 CO H 2 O 1 O N min 3 SOFCs integrated into current energy system e,f,r,s,t f,t p c x + c y Biogas hourly profile Collegno WWTP, Turin Giarola et al. (2017). Accepted Manuscript in Applied Energy 7

8 LCOE, /kwh Technological learning Cost reduction needed to cut 68 % of CAPEX (~10 k modules) 0,15 0,1 0,05 SOFC SOFC-60 MGT ICE 0 CAPEX_8303 CAPEX_3346 CAPEX_2077 Giarola et al. (2017). Accepted Manuscript in Applied Energy 8

9 LCOE, /kwh High efficiency sludge handling (TSS 8 %) 0,15 0,1 0,05 0 SOFC SOFC-60 MGT ICE Giarola et al. (2017). Accepted Manuscript in Applied Energy 9

10 1. Market potential: eligibility General stats ~ 23,000 WWT plants in Europe 15,000 GWh/y energy need 27 Mt CO 2 -eq/y emissions m 3 /y biogas Eligibility i. WWTP suitable for AD>20,000 P.E. ii. With secondary biological treatment DE ES UK IT FR PL NL 10

11 2. Market potential: assumptions a) Size WWTP size Persons Equivalent Electricity consumption, kwhe/pe XS 20,000 60, S 60, , M 150, ,000 L 350, ,000 XL 750,000 > 1,100, b) Thermal load: Suspended Solids: 3 % Air and ground daily temperature Digester temperature (42 C) Sludge residence time (20 days) a) Biogas profile: Archetypal profiles - Collegno (XS,S,M), Castiglione (L,XL) 11

12 3. Market potential: energy costs WWTP size Natural gas, GJ/y XS 1,000 10,000 S M L XL 10, ,000 Electricity, MWh/y 500 2,000 2,000 20,000 20,000 70,000 WWTP size Natural gas, /kwh XS S M L XL Electricity, /kwh

13 Utilization Costs, k /y 4. Market potential: optimal cell number WWTP 150, ,000 PE 100% 80% 60% 40% 20% 0% number of modules Technology Utilization Biogas Utilization Total Costs, k /y Operating Costs, k /y 13

14 5. Market potential: SOFC capacity per size i. Average 2016 EU natural gas and electricity prices ii. iii. Average European temperature Specific Biogas production: 10 L/PE/day WWTP size SOFC unit capacity, kw Total SOFC installed capacity, kw Technology utilisation (%) Persons Equivalent Module number XS 20, % S 90, % M 210, % L 450, % XL 1,100, ,500 1, % 66 % 14

15 6. Market potential: sensitivity i. Natural gas and electricity prices (± 50%) ii. iii. Location (hottest and coldest European cities) Advanced sludge technologies (to increase TSS) The most influential parameter is the biogas availability MWe SOFC capacity in current WWTP market ~ 9,000 14,000 modules of 58.3 kw If a specific biogas production of 20 L/PE/day is considered, the market potential could nearly double 15

16 Take-home message Current costs of SOFC do not quite compete with alternative technologies, but implementation of more efficient sludge handling technologies in WWTPs would make the investment more attractive in this application There is potential for up to 14,000 modules (58 kw units) in the WWTPs in Europe, considering the current AD technology The current market for SOFCs in WWTPs gives evidence to support the technology diffusion and favour technology cost reduction If the number of manufactured units reached 10,000 units the capital costs of SOFCs would fall by more than 60 % 16

17 Thank you for your attention