Let me dwell on this. In an ideal situation (I know Kenya is corrupt), all IPP are paid on the same metrics. For example:
-kshs 5/kW per month installed capacity + kshs2/kWh of supplied power.
Mote that the figures are for illustration purposes. I don't have actual figures.
So, a 100MW plant will receive kshs. 500,000 whether they produce or not.
Now suppose stations A and B both have the same 100MW capacity, but station A supplies only 10MWH while B supplies 500,000MWH within the same period.
A will be paid 500000 (fixed charge) + 20,000 for supply. Total 520000 for supplying 10mwh, that's at an average of 52 bob per unit.
Station B will paid 500k fixed plus 50m , total 50.5m to supply 500,000MWh, translating to around shs. 10.1 per unit.
That explains why two stations with the same capacity will be paid differently.
It also explains what a certain CS meant when he said that power costs can go down if we consume more.