Of the total electricity generated in Canada, approximately 17% (120 million megawatt hours) is from the combustion of coal and oil. Current generating capacity of coal- and oil-fired power plants is about 24,700 megawatts. These plants comprise steam electric plants (boilers), combustion turbines and internal combustion engines. Coal-fired boilers account for 70% of the capacity in this category of plants.

The coal- and oil-fired facilities account for the majority of air emissions from the electric power sector. The most prominent of these air emissions are nitrogen oxides (NOx), sulphur dioxide (SO₂), particulate matter (PM), mercury and greenhouse gases such as carbon dioxide (CO₂). Small amounts of toxic metals such as arsenic, cadmium, chromium and nickel are also released. Major environmental issues related to the pollutants emitted are acid rain, smog, toxic substances and climate change.

Switching old coal boilers to natural gas combined cycle, in combination with the existing steam turbines, will dramatically reduce all types of emissions. However, due to natural gas supply limitations, energy generation by smaller combined heat and power projects is a superior solution for new facilities.

Environment Canada's long-term goal for coal- and oil-fired plants is “clean as gas” for all pollutants. The term "clean as gas" is generally understood within Environment Canada to mean air emissions comparable to those of an efficient, natural gas-fired combined cycle generating unit, for all pollutants. For greenhouse gases, the Climate Change Plan for Canada includes the goal of “clean as gas” by 2010.

In January 2003, Environment Canada released the New Source Emission Guidelines for Thermal Electricity Generation under the Canadian Environmental Protection Act. These Guidelines provide limits for emissions of SO₂, NOx and PM from new fossil-fuel fired steam-cycle combustion units (boilers). They will be revised over time to include mercury and to reflect new technology. Environment Canada also has Codes of Practice for steam electric power generation.

Environment Canada led the development of the National Emission Guideline for Stationary Combustion Turbines, published by the Canadian Council of Ministers of the Environment in December 1992. This Guideline is used today by many provincial permitting agencies.

Use the following link for information on:

• Regional mix of dominant electricity sources
• Canada's Energy Sector
• Coal Association of Canada