Power plant emissions under examination
By Contributor
North America’s 3,000 fossil fuel-burning power plants continue to produce two-thirds of the region’s electricity and, at the same time, generate the majority of certain harmful air pollutants and emit more greenhouse gases than any other industrial sector.
North American Power Plant Air Emissions, a new report and database released today by the Commission for Environmental Cooperation (CEC), provides detailed information on the electric power sector in North America, and profiles, on a plant-by-plant basis, the air emissions of six of the most-important contaminants—the greenhouse gases carbon dioxide, nitrogen oxides, and methane; sulfur dioxide; mercury; and particulate matter—emitted by North America’s fossil fuel-fired power plants.
These pollutants—especially sulfur dioxide, mercury and greenhouse gases—are linked to a range of environmental and public health problems facing the people of North America today, including acid rain, smog, asthma, and global climate change. For sulfur dioxide alone, the major contributor to acid rain, fossil-fuel power plants are responsible for 71 percent of reported emissions from industrial facilities across North America.
“The information we’ve collected in this report is vital to understanding the magnitude and impact of these power plant emissions on our environment, climate, and health, not just locally but across North America,” said CEC Executive Director Evan Lloyd.
“North America’s continuing reliance on fossil fuel electricity comes at a steep price in terms of air pollution and public health, and underlines the challenge, and the long-term benefits, of making the transition to a cleaner, low-carbon economy. The detailed information found here will help industry, regional and federal authorities in Canada, Mexico and the United States make better decisions on energy alternatives and on reducing and preventing pollution,” said Lloyd.
Greenhouse gases
North America’s fossil-fuel electricity generating sector is a major contributor to emissions of greenhouse gases, representing 33 percent of North American and six percent of global emissions, mainly carbon dioxide. The combustion of coal accounts for the bulk of these emissions. Coal-fired power plants in Canada and the United States, along with Mexican oil-fired facilities, produced the largest emissions overall of greenhouse gases (GHGs), particularly CO2, although in Canada and Mexico, natural gas-fired power plants were major sources of methane as well as nitrous oxide, both extremely potent greenhouse gases.
Sulfur dioxide
The CEC study finds that a relatively small percentage of facilities across the region account for much of the sector’s sulfur dioxide (SO2) emissions, a criteria air contaminant associated with a variety of impacts on the environment and human health—including the creation of smog, acid rain and regional haze, and the development of respiratory illnesses. The report reveals that the overall per-plant emission levels of the top five SO2 emitters of Mexico and the United States were very similar, and significantly higher than those of the top five SO2 emitters of Canada.
Mercury
The data in this report show that mercury emissions in the three countries were mainly from the combustion of coal. For Canada and the United States, coal-fired power plants accounted for 98 percent of all mercury releases from fossil-fuel electricity generating facilities, and in Mexico, they accounted for nearly 88 percent.
Gauging environmental performance
The report reveals that factors other than fuel type, such as total electricity generation, capacity, age and efficiency of power plants, also figure significantly—with many of the top pollutant emitting facilities not necessarily the top electricity generators. For instance, for the pollutants considered in the report, per capita emissions are higher in the United States than in Canada and Mexico.
However, for certain pollutants, such as CO2, overall the largest US facilities, many of them coal-fired power plants, had lower emissions per unit of electricity produced than the largest facilities in Canada and Mexico. Similarly, for SO2, Mexico’s three highest emitters had considerably higher emissions per unit of electricity produced than the highest three emitters of Canada and the United States, suggesting differences in environmental controls and performance.
A North American picture of power plants
The report compiles data from 2005, the latest publicly available information from all three countries. The report reveals the relationship between pollutant emissions and the type and size of facilities and the technologies and fuels they use—a unique mix for each country. For instance, coal-fired plants in the United States generate close to half of that country’s electricity, while Canada produces 60 percent of its electricity from hydroelectric generation. In Mexico, oil and natural gas-fired plants generate more than two-thirds of that country’s electricity.
North American Power Plant Air Emissions builds upon the first-such CEC assessment (published in 2004) that compiled information on emissions of two criteria air contaminants and limited information on mercury and carbon dioxide emissions from power plants in North America for the year 2002. The latest report provides a more extensive coverage, with analyses from over two thousand additional facilities and of additional pollutants, including methane, nitrous oxide and particulate matter, thereby offering a more complete picture of power plant contributions to air emissions across North America.
The current report also highlights some of the significant emission reductions achieved by a number of power plants featured in the previous publication. The report also notes that from 2002 to 2005 increases in electricity production have also been accompanied by increases in the use of relatively cleaner fuels such as natural gas, increased use of fuels from renewable sources, as well as the implementation of control technologies.
The report also makes a statement about the importance of improved availability and comparability of pollutant emissions data from the three countries. Although the emissions inventory data for Canada and Mexico have improved significantly from 2002 to 2005, they are not yet at par with the level of detail of the US data. Facility-level data on electricity generation or pollution-control technologies for Canadian facilities are not publically available. In Mexico, the majority of the air emissions data were estimates based on facility fuel consumption, due to the lack of site-specific monitoring data.
North American Power Plant Air Emissions Online
You can read the report and explore the CEC’s air emissions database for 3,144 fossil-fuel power plants online at www.cec.org/powerplants. The data can be downloaded and can also be viewed using Google Earth. A PDF of the report is also available for download.
The Commission for Environmental Cooperation (CEC) was established by Canada, Mexico and the United States to implement the North American Agreement on Environmental Cooperation (NAAEC), the environmental side accord to NAFTA. The CEC supports cooperation among the NAFTA partners to address environmental issues of continental concern, including the environmental challenges and opportunities presented by continent-wide free trade. More information at www.cec.org.
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