The long awaited supply mix advice and recommendations report by Canada’s Ontario Power Authority (OPA) has been published.

The recommendations suggest that government maintains the share of nuclear generation and replaces coal by increasing the share of gas-fired generation and renewable resources.

The report presents OPA recommendations to the energy minister on options for the future development of Ontario’s electricity system in response to a May request for advice on the appropriate energy mix out to 2025.

The report predicts a province-wide capacity shortfall later this decade which grows rapidly over time. The shortfall stems primarily from Ontario’s shrinking supply as a result of a lack of investment over the past decade, with growth in demand as an important secondary factor.

“With supply already tight as a result of this underinvestment, the sector faces the loss of a major part of its current supply mix as most units of its nuclear fleet reach the end of their design life over the next several years,” the report says, adding: “The loss of nuclear generation would come immediately on the heels of replacement of coal-fired stations, scheduled for completion by 2009. Together, the combination of demand growth and generation retirements would create a gap of roughly 24,000MWe by 2025, equivalent to about 80% of Ontario’s current capacity.”

The report calls for decisions to be made soon to ensure a combination of resources and technologies and concludes that energy policy should maximise conservation and renewables, adopt a ‘smart gas’ strategy and benefit from supply options that need long lead times, such as nuclear.

The report calls for up to C$40 billion ($34.8 billion) worth of new nuclear power projects in Ontario over the next 20 years as part of an overall strategy to maintain a 50% share of Ontario’s electricity supply mix from nuclear, a strategy which if executed would be expected to require at least one new station with four units.

In an interview with The Canadian Press, Pierre Charlebois, Ontario Power Generation’s chief nuclear officer said: “If a decision is to be made… our Darlington site clearly would be an ideal site for a new build.” The Canadian government has reportedly been looking at the possibility of building two 900MWe Candu reactors at the site.

AECL, developers of Candu technology, welcomed the report’s recommendations with president and chief executive Robert Van Adel saying: “We are very encouraged by the OPA’s recommendations regarding the importance of maximising the capabilities of existing nuclear plants and the role of new nuclear power plants in Ontario’s future energy mix.” He added: “We also agree with the OPA recommendation to move swiftly with decisions on the best way to ensure the nuclear option will be there when Ontario needs it.”