Thunder Bay Generating Station is a defunct biomass-fired thermal power station owned by Ontario Power Generation ("OPG"). It is located on Mission Island in Thunder Bay, on the shore of Lake Superior. Thunder Bay GS was in operation from 1963 to 2018. It was the last coal fired station in Ontario. The plant was initially shut down in April 2014 as part of Ontario's phase out of coal-fired electricity generation, before being converted to run on advanced biomass (wood pellets) and recommissioned on February 9, 2015.