Ontario Power Generation hopes to generate more hydroelectric power in the province by upgrading its existing dams with new technology and building massive new ones in the province's north as Ontario prepares to phase out its coal-fired power plants.

In the past few years, the company has been going through its inventory of 64 hydroelectric plants and upgrading them with improved technology, which will cost about $72 million by 2012, spokesman John Earl said Tuesday.

The new runner blades, which are turned by the water rushing past to generate electricity, were expected to generate 500 megawatts more power than the old blades, or roughly enough for 500,000 homes.

The company's hydro plants currently generate almost 7000 megawatts, and hydroelectricity generates around 30 per cent of the province's power.

The upgrades weren't prompted by the province's plan to close its coal-fired plants by 2014, as they are the responsibility of the Ontario Power Authority, Earl said.

But the extra power produced after the upgrades will count when the coal plants, which supply 20 per cent of the province's power, are no longer available.

Almost 30 per cent of the company's plants have been upgraded already, and in progress is a $10 million retrofit of Chats Falls Station in Fiztroy Harbour, Ont. That is expected to boost the station's capacity by five per cent or enough power for about 2,000 homes when it is completed in 2010.

Meanwhile, a new tunnel is being built to increase capacity at Niagara Falls and some smaller plants are also being expanded.

2 new dams planned

Ontario Power Generation is also looking into building two new hydro developments on the Mattagami, Abitibi or Albany River systems in northern Ontario, which would generate about 334 megawatts at a cost of around $1.3 billion.

Hydroelectric power is relatively cheap and less controversial than power generated by coal, which produces air pollution and nuclear power, which produces radioactive waste.

But some environmentalists still worry about the new dams Ontario Power Generation might have in mind.

Meredith Brown, executive director of Ottawa Riverkeeper, a group dedicated to protecting and promoting the ecological health of the Ottawa River, said dams change the flows of rivers, and therefore alter the diversity of plants and animals that live there. They also act as barriers to species that travel the river, she said.

But Ontario Power Generation spokesman David Abbott said the company plans to work very co-operatively with First Nations and other communities and go through the proper environmental assessments in the development of its new projects.

Despite all those plans, he said he doesn't see Ontario going back to the way it was decades ago, when hydroelectricity supplied all of the province's power.

"I can't imagine, looking ahead, a scenario in Ontario where nuclear power does not play a significant role down the road as it does today," he said.