An article by Donald Jones in the Toronto Star, from March 2009, was an early indication of the problems integrating intermittent generation with Ontario’s baseload nuclear capacity
Although nuclear units can handle the daily and weekend changes in electricity demand, they have limited capability for the kind of frequent power-up and power-down requirements that would be needed for this support. Furthermore, hydroelectric plants may not always be available due to fluctuations in water supply and water management agreements.
Even without restrictions on nuclear and hydro, it makes little economic sense to run reliable suppliers of steady power, with high fixed costs and low operating costs, at reduced output to support the expensive, intermittent and varying output from wind farms.
So, with coal being phased out by 2014, natural gas-fired generation will have to be used to support wind. Due to the simultaneous demands of home heating and electricity generation in the winter, that may lead to gas shortages. So some of these plants may be dual fuelled with gas and oil, which is not a pleasant thought.
The Ontario government is putting too much faith in natural gas for electricity generation, as the United Kingdom did with its “dash for gas” from the North Sea in the 1990s when gas was cheap. Now the U.K. is in terrible shape with its gas running out and the threat of power shortages in the next decade.