I think the concerns expressed over the building of cogen plants in the GTA may be missing an important consideration.
I understand that there may be grid stability arguments for replacing the coal-fired generation previously supplied by Lakeview GS with cogen plants in the GTA. The Lakeview Generating Station produced up to 300 MWe from 8 units starting from 1 unit in 1961, reaching 8 in 1969. Operation continued until 1993 when 4 were retired. The station provided peak power generation from 1994 to April 30 2005. ( www.opg.com/ops/lakeviewfinal.pdf )
In the period 1998 to 2000 there was an initiative to introduce a 550 MW natural gas fired combined cycle plant at the Lakeview site. This didn't proceed.
Given current practices, a new nuclear generating station would not be built in such locations.
I expect that there is a defensible engineering argument for building cogen plants in Brampton, Mississauga, and at Lakeview. There are other means to achieve the desired electrical grid performance using generating stations that are more remote from the load centres such as those implemented by Hydro Québec for the Montréal area in particular following the ice storm. These require more transmission lines which are not trivial to develop in built up areas and electrical systems to maintain the power system stability / quality. (G-2 was previously credited with providing an essential stabilizing influence on the HQ grid, but when I asked about how that would be accommodated during a G-2 refurbishment, I learned that electrical system alternatives have been implemented.)
So, encouraging a private utility to build a cogen plant with revenue guarantees must be very attractive compared to borrowing the capital necessary to advance other schemes. Given the supply limitations of natural gas and the price volatility, it might even be a good business decision?
It's interesting to speculate about how these problems will be addressed in the future when gas-fired cogen plants cease to be a viable option. I find it hard to imagine that even "passively safe" nuclear generators would be located with very small or no exclusion areas in urban settings for some time to come. While the safety arguments may well show that this should be acceptable, I think it will take public perception and regulatory practice a long time to accommodate such practise.
The only thing that's obvious to me in all this is that "the answer isn't blowing in the wind," notwithstanding the enthusiasm Premier McGuinty and his hero David Suzuki have shown for wind generators.