Type: |
Input Variable |
|
Units: |
% |
|
Symbol: |
τ |
The maximum output of a cofired generator operating at the minimum fossil fraction, as a percentage of its rated output. For example, say a 20 kW diesel generator is modified to run on a mixture of diesel fuel and biogas, with a minimum diesel of 20%. If the output of the engine is limited to 15 kW when operating at 20% diesel fraction, the derating factor would be 15 kW divided by 20 kW, or 75%.
Note that HOMER assumes a co-fired generator can produce up to 100% of its rated output, provided the fossil fraction is high enough. In the above example, the generator could produce up to 20 kW, but the diesel fraction would have to exceed 20% for any output power above 15 kW.
For a more complete explanation of a cofired generator, see Operation of a Cofired Generator.