Ontario's electricity system operator is preparing for a step-change in grid capacity as demand is projected to rise nearly 65% by 2050, with peak load increasing from roughly 23–24 GW today to as high as 40 GW in high-demand scenarios, according to the Independent Electricity System Operator 2026 Annual Planning Outlook. Planning models show the most acute increases are concentrated in southern Ontario, particularly in the Greater Toronto area, where electrification of buildings, transportation and industry is driving sustained peak demand growth. Individual large loads are amplifying that pressure. Data centers and electrified industrial facilities can add several hundred megawatts at a time, creating localized spikes that existing transmission infrastructure cannot absorb. Ontario expects 16 more data centers to connect to its grid over the next decade, representing 13% of new electricity demand and 4% of total anticipated demand, according to analysis published in Energy Regulation Quarterly .…