In 2017, Ontario's gross exports were 19.1 TWh, i.e. roughly equal to half its hydro generation of 37.7 TWh in 2017. (Although Canada is the world's third-largest producer of natural gas, Ontario imports natural gas from the United States and from western Canada.) If all the carbon emissions associated with natural gas-fueled generation were allocated to the exports, almost all the electricity consumed within Ontario would be from non-carbon or carbon neutral sources. (Note however that the natural gas generation is not necessarily coincident with exports and natural gas plants sometimes need to be operated due to regional transmission constraints, and as backup for wind generation which is intermittent and somewhat unpredictable.)