Tennessee Valley Authority
Air Quality
Through the power distributors of the Tennessee Valley, TVA provides some 8.8 million consumers with reliable electric power at an affordable price. This massive public power system, the largest in the nation, provides a service that operates for the public good rather than the need to generate profits.
Public service also means public responsibility, and power generation across an 80,000-square-mile service area cannot help affecting the environment. More than half of TVA’s power is generated by the burning of fossil fuels, and this process inevitably releases chemical emissions into the atmosphere.
Plant modifications
TVA has one of the most aggressive emission control programs in the nation. By 2010, it will have spent about $5.7 billion on clean air modifications to its plants.
- Currently, 30 percent of TVA’s coal-fired capacity is equipped with scrubbers to control sulfur dioxide (SO2), while only 16 percent of the coal-fired capacity of surrounding utilities has scrubbers.
- At present, 60 percent of TVA’s coal-fired capacity is equipped with selective catalytic reduction (SCR) equipment to control nitrogen oxides (NOx), while only 28 percent of the coal-fired capacity of surrounding utilities has SCRs.
These modifications have produced significant results. Emissions of SO2 and NOx in 2005 were the lowest on record even as TVA was supplying the third-highest calendar year fossil system on record.
- By 2005, TVA had reduced ozone-season (May - September) NOx emissions by 80 percent below 1995 levels.
- It is also on track to fulfill its commitment to reduce SO2 emissions by 80-85 percent below 1977 levels by 2010. SO2 emissions in 2005 were about 460,000 tons, 80 percent below 1977 levels.
For further details about TVA’s clean air modifications and a graph showing emission reduction achievements, see the sulfur dioxide and nitrogen oxides pages. Also see the menus at right for added information on emission controls and what TVA is doing at each of its fossil sites.
How Clean Is the Air?
This July 2003 report provides a look at air quality in the east-central United States, showing trends from 1979 through 2002. An analysis of EPA data over the past quarter-century indicates that the air in this region is good and getting better. View the report here (PDF, 1.1 mb, requires Adobe Acrobat Reader).
Air quality standards
Check here for information on the federal environmental standards that affect TVA’s power generation.
On the Air
These pages present technical reports on important air quality issues.
Scientific papers
TVA carries out many research projects related to air quality and other environmental issues. See a bibliography of recent scientific papers.