The IESO’s Hybrid Resource Portfolio Equivalency Assessment (August 2025) demonstrated that portfolios built from wind, solar, and battery storage can meet Ontario’s electricity needs with reliability approaching 99.9 percent load served in modelled scenarios, all the way out to 2050.
That finding should have clarified Ontario’s path forward. Instead, the Minister of Energy rejected that direction and directed the IESO to advance new hydropower procurement, stating that these competing technologies “are deemed not well-suited to competing against resources with shorter development timelines and lifespans… but are able to offer unique benefits to Ontario’s electricity system through resource diversification.” Unfortunately, the Minister did not identify or quantify these ‘unique benefits,’ nor demonstrate that they outweigh the higher cost, longer timelines, and increased risk associated with hydropower.