Premier Dalton McGuinty promised that Ontario would be bound by law to close its coal plants by 2014 to reduce greenhouse gas emissions.
With a regulation that dictates the closures, people now have 30 days to submit their thoughts and suggestions, including what can be done to convert the plants into more environmentally friendly facilities.
The regulation means any subsequent government will have to change the law if it wants to keep the plants open.
Dave Martin of Greenpeace says the regulation is a disappointment because it allows the plants to stay open until the end of 2014.
He says the province could start phasing out coal much earlier and leave only a few plants open until the deadline.