Fairfax County, Va., plans to integrate wind energy into its electricity supply. It signed a two-year contract in April with Herndon, Va.-based Washington Gas Energy Services to purchase 5.8 million kilowatt hours of renewable energy credits — about 5 percent of its electricity — each year from a wind farm in Tucker County, W.Va. The use of wind energy, which will cost the county $92,800 annually, is intended to help meet the region's air quality attainment goals and reduce particulate matter and ground-level ozone pollution. The Washington metropolitan area is designated a non-attainment area by the Environmental Protection Agency, and all localities in the region must submit smog-reduction plans by May 3. The county estimates the wind energy will reduce carbon dioxide by 6.3 million pounds, sulfur dioxides by 23,200 pounds and nitrogen oxides by 11,600 pounds annually.