The leaders of the United States, Canada and Mexico will pledge on Wednesday that by 2025 half of their overall electricity generation will come from clean power sources, according to administration officials. The commitment — which will be a joint one, rather than an individual commitment by each nation — represents an aggressive target given the reliance by the United States and Mexico on fossil fuels for much of their electricity supply. Roughly 59 percent of Canada’s electricity is generated by hydropower operations, with another 16 percent coming from nuclear plants, so it has already surpassed the targeted benchmark. The new commitment includes not just renewables but also nuclear power, carbon capture and storage plants, and […]