Believe it or not, reliability of source is considered into the grid rate base for each generation unit. If a coal plant has to come up to compensate for unexpected decrease in supply, it comes out of the wind generator rate. However, they only compensate for the average coal rate for the unit, not the extra costs to bring a plant on line.
Re: reliability of source is considered into the grid rate base
Hum, perhaps in some states, but not all. In the analysis of the recent Texas rolling blackouts, it was reported that the 9300 MW of wind energy in Texas was not required to post the same “provide-or-pay” as natural gas or coal generation. This resulted in a burden and cost transfer to the non-wind generation capacity in the state, thus raising the overall rates in the state.
I understand twelve coal fired plants were cancelled in Texas over the past several years, while all the wind power was coming online.
Wind info:
http://windpowerfacts.info/
WSJ article on wind not paying their way:
http://online.wsj.com/article/SB10001424052748704188104575083982637451248.html
http://www.sourcewatch.org boasts of the following cancelled coal fired plants in Texas:
Cancelled:
Big Brown 3
Lake Creek 3
La Porte IGCC Plant
Martin Lake 4
Monticello 4
Morgan Creek 3 & 4
Morgan Creek 7
Nueces IGCC Plant
Tradinghouse 3 & 4
Twin Oaks Power Unit 3
TXE Industrial Gasification Facility
Valley 4