The pair of "green scenarios" put forward by the environmental groups emphasize energy efficiency and conservation while greatly expanding the reliance on renewable wind, solar and hydroelectric power, some of which may be imported from Quebec.
"We can keep the lights on without coal or nuclear power," WWF-Canada climate change campaign manager Keith Stewart said.
Stewart said nuclear power is unreliable and costly, adding that smaller, more localized renewable energy projects would be more efficient since they will reduce the amount of energy lost through transmission.
The green model also calls for more emphasis on co-generation, which would see large amounts of wasted energy from industrial and commercial enterprises converted into usable power.
"None of this requires doing anything that hasn't been done somewhere else already. It could provide a whole new centre for innovation and jobs for Ontario's economy and it could make sure that Ontario does its part to stop global warming and meet our Kyoto obligations," Stewart said.
Through greater use of solar panels and the creation of storage facilities for wind projects, the groups hope Ontario will catch up to nations with more advanced green energy policies such as Germany within 20 years.
But while the groups' plan to use renewable energy to balance Ontario's future electricity supply and demand challenges may be "admirable," Ontario Energy Association president Shane Pospisil suggested it's not realistic.
Despite the fact that several nuclear reactors are out of commission, Pospisil said nuclear power accounts for about half the province's electricity needs.
"There's no doubt that renewables... are going to increase in importance," he said. "But at the end of the day, we need that base load power. It's not often that the wind blows 24-7, but these base load plants are often looked upon to really provide this clean, reliable, competitively priced electricity."
Chris Holz, a spokesman for Energy Minister Dwight Duncan, agrees with the study entitled "renewable is doable," but believes any electricity production model must have a good balance that includes nuclear power.
He said the province has made great strides forward in terms of renewable energy and conservation, adding 400 megawatts of wind power to the grid over the last three years and encouraging consumers to go green through incentives like the Refrigerator Retirement Program that provides free pick-up and recycling of old, inefficient fridges.
"I think removing the nuclear base load supply that Ontario industry and homes and hospitals need... I don't think it's achievable. I don't think it's realistic," he said.
OPA spokesman Tim Taylor said their final electricity production plan will be submitted to the Ontario Energy Board later in August. During the public hearing process, he said, all stakeholders will get a chance to offer their opinions and advice.