Air

Greenhouse gases
(continued)

The electricity industry accounts for about 18 per cent of Canada’s greenhouse gas emissions. Coal-fueled electricity accounts for most of the industry’s emissions (84 per cent), followed by natural gas-fueled generation (nine per cent) and oil-fueled generation (seven per cent). Most of these emissions result from fossil fuels burned to produce heat and steam to drive turbines that generate electricity.

In recent years, the electricity industry has slowed the rate of greenhouse gas emissions growth through new technologies and energy efficiency initiatives. In 2001, the greenhouse gas emission intensity of Canada’s major power companies was 0.92 kilograms of carbon dioxide-equivalent per kilowatt-hour, compared with 0.98 kilograms per kilowatt-hour in 1997.

The electricity industry’s carbon dioxide emissions are expected to increase in 2010 to about 130 megatonnes, or about 35 per cent above 1990 levels. Growing consumer demand for electricity is a major reason for increased greenhouse gas emissions. According to the Canadian Electricity Association (CEA), this demand is expected to grow between one per cent and 1.5 per cent yearly over the next decade and beyond.

The industry is using a comprehensive set of strategies to address greenhouse gas emissions:

• efficiency improvements and energy conservation
  The efficient use of electricity contributes to operating savings and helps to lower greenhouse gas emissions. Power companies are improving their energy efficiency through changes in operating practices, by using high efficiency motors, pumps and other types of equipment, and by turning off equipment when it is not required.
  
  
• cleaner fuels
  Many new generation facilities use natural gas or gasified coal. Natural and synthetic gases burn relatively cleanly, producing about 50 per cent to 65 per cent of the greenhouse gas emissions of older coal and oil burners.
  
  
• advanced combustion technologies
  Some power companies are retrofitting older generating plants with advanced generation technologies to improve operating and environmental efficiencies. One example is combined-cycle cogeneration. This technology can transform up to 80 per cent to 90 per cent of the energy in natural gas into electricity and useful heat, by capturing waste heat from exhaust gases to produce more electricity. This is compared to traditional simple cycle plants that vent much of their heat through flue gas and cooling water systems and operate at 30 per cent to 40 per cent efficiency.