Fuel cells and electrolysers in future energy systems - VBN

Annex II. PAFC
Technology (2008‐prices) PAFC system Ref.
Year 2000‐4 2010‐15 2020‐30
Data type Unit Status Potential Potential
General data
Fuel H2 H2 H2 [16]
Poisonous substances CO, S, NH3 CO, S, NH3 CO, S, NH3 [3]
Diluents CO2, CH4 CO2, CH4 CO2, CH4 [3]
Operation temperature ˚C 180‐220 180‐220 180‐220 [2]
System capacity MWe 0,2 0,05‐5 0,05‐5 [2;3;16]
Total system efficiency 9 % 87 90‐100 90‐100 [2;3]
Electricity efficiency % 37‐42 37‐42 45 [4;16;25;52]
Start‐up fuel consumption GJ/MW ‐ ‐ ‐
Time for start up from cold 10 Hours Several Several Several [6]
Idle fuel consumption MJ/hour ‐ ‐ ‐
Technical lifetime (system) Years ‐ ‐ ‐
Technical lifetime (cells/stacks) Hours 30.000‐53.000 >50.000 >50.000 [3;16;51]
Degradation 11 %/1.000 hours 0,2‐0,7 ‐ ‐ [25;51]
Power density 12 W/cm 2 0,1‐0,26 ‐ ‐ [4;16;25;51]
System weight kg/kW ‐ ‐ ‐
System volume kW/l 0,07 0,08 0,1 [2]
Regulation ability
Fast reserve kW/15 min All All All
Regulation speed kW/second 0,2 0,05‐5 0,05‐5
Minimum load % of full load ‐ ‐ ‐
Financial data 13
Specific investments M€/MWel 2,5‐4,4 2,5 1,9 [2;51;52]
9 For HT‐PEMFC, 90‐100 per cent total efficiency has been achieved and may also be possible for PAFC.
10 The start‐up time, start‐up and idle fuel consumption can be eliminated in SOFCs by operating at least once a day or by cyclic reheating.
The same may be possible for PAFC, but no analyses of this ability have been identified. One of the problems are the fact that the phos‐
phoric acid is solid at a temperature of 40 °C [42].
11 Degradation was reported as 3% over 6.000 hours in 2002 [25].
12
The power density has been proved to be 0,31 W/cm2 if the pressure is increased to approx. 8 atm., thus lowering the costs of the
stacks. However, this requires high pressures which would increase the system costs again [16].
13 Only one estimate of potential future investment costs have been identified [2]. Two references confirm the current prices between
2,500 and 4.000 €/KW [51;52]. Fixed operation and maintenance costs depend on the technical lifetime of the system compared to the
lifetimes of the cells and stacks. Variable operation costs are between 0,004 and 0,011 €/KWh [52].
17