The Serpa solar power plant in southern Portugal is an 11-megawatt plant that spreads across a 60-hectare hillside in Serpa, 200 kilometres southeast of Lisbon. A solar farm to be built near Sarnia, Ont., is expected to supply 40 megawatts to Ontario by 2010. ((Antonio Carrapato/Associated Press))

The Ontario government has approved a California company's plan to build North America's largest photovoltaic solar farm, the provincial energy ministry announced Thursday.

OptiSolar Farms Canada Inc. of Arthur, Ont. — a subsidiary of California-based OptiSolar Inc. — will install more than one million solar panels at four farms outside Sarnia, Ont., providing the province with 40 megawatts of power by 2010. Ontario Energy Minister Dwight Duncan said that'senough to power 6,000 homes.

The government awarded the contract through the Standard Offer Program, which pays a premium for electricity from small-scale renewable energy providers.

"The Standard Offer Program is transforming the way we generate electricity in Ontario," Duncan said in a statement Thursday. "This program is giving Ontarians the opportunity to help strengthen our energy system and clean up our air."

OptiSolar will sell the power it generates to the Ontario government, who in turn would sell it to local energy provider Bluewater Power.

OptiSolar will be paid 42 cents a kilowatt-hour for the solar power generated, a much higher premium than the 11 cents a kilowatt-hour paid for wind power, another source of "green" energy in which the province has invested.

"The Ontario government has chosen to take a world-leading role in encouraging the development of renewable energy, and the Standard Offer Program is making things happen," OptiSolar Farms vice-president Peter Carrie said. "Our goal is to make solar power a mainstream energy source."

The project would be the largest in North America using photovoltaic solar cells, which collect energy from the sun's rays and convert it into electricity.

It's also larger than any other existing solar-cell plant in the world, although a number of projects underway would surpass or equal its size. Construction of a 40-megawatt project in Germany is already underway, and last fall, the Australian government announced funding for a proposed 154-megawatt solar power plant to be built in Victoria state and expected to be fully operational by 2013.

Power plants using solar energy and operated in the Mojave Desert generate more than 300 megawatts of power, but those plants are powered through solar thermal energy, a different form of power generation that collects the sun's rays and uses them to heat a liquid that then acts to produce electricity.

The Sarnia solar farm was one of 14 new alternative energy initiatives announced by the government to add more than 107 megawatts of power to the grid. Two new water-power projects with Ontario First Nations were also announced.

The projects represent only a small part of Ontario's total energy consumption. Last year, Ontario had a peak demand of 27,000 megawatts.

With files from the Canadian Press