Marmora pumped storage project would turn inactive open-pit mine into giant hydro battery

In what would be a first for Canada, Ontario Power Generation and Northland Power Inc. are proposing an innovative pumped storage project that would convert a sprawling, inactive open-pit mine into a 400-megawatt hydroelectric battery. The closed-loop facility could power up to 400,000 homes at peak demand with clean, renewable electricity for up to five hours. Repurposing a former mine for pumped storage purposes would be a “first” in Canada.