Ontario's coal-fired power plants may not be closed until 2014.

A report to be released Wednesday by the Ontario Power Authority (OPA)  pushes the closing date of the province's four coal-fired plants back substantially from the previous projection.

The McGuinty Liberals made an election promise to close all four of the province's coal-fired plants by 2007. Ontario later pushed the time frame back for two of the four plants to 2009.

But now the OPA says the province may need a backup source of electricity, in case replacement generation or transmission facilities aren't working in time.

Notes in a speech to be made in Toronto by Ontario Power Authority CEO Jan Carr suggest two of the province's four coal-fired plants be closed by 2011, and the other two by 2014.

The dates were noted in Carr's speaking notes, but never made it into his formal speech.

Coal plants currently provide nearly one-fifth of Ontario's electricity supply.