If I take wind as an example, because it is the largest by far of the non-traditional renewables, a rule of thumb is that a subsidy of about 2¢ a kilowatt hour is needed to make it cost-competitive. It obviously varies from jurisdiction to jurisdiction and from site to site, but that's not a bad rule of thumb. The ecoENERGY renewables program provides about half of that, 1¢ per kilowatt hour.
There are wind projects that would be economical with support of 1¢ per kilowatt hour, but on average that means provinces would have to contribute roughly the same amount for the program to reach its full potential. There are many different ways that can be done. It can be done, as in Ontario, through a request for proposals for renewable power projects, for example. It could be done through mandates. It could be done through cash contributions.
What we have at the end of the day is a very flexible and informal--but effective--joint effort between the federal government and the provinces.