South Texas Electric Cooperative is a cutting-edge Generation and Transmission Cooperative and a leader in providing a diverse portfolio of affordable energy, a reliable power delivery system, and services customized to the needs of the members. STEC was formed in 1944 to provide wholesale electric services to member distribution cooperatives. STEC’s membership consists of 9 distribution cooperatives that serve over 241,000 members in forty-two South Texas counties.
STEC's headquarters facility is located at the Sam Rayburn Power Plant Complex on the Guadalupe River just outside Nursery, Texas. Transmission line and substation service facilities are also located in Pearsall, Texas and Donna, Texas.
Power provided by STEC to its members is generated from a variety of energy sources, including wind, lignite, natural gas (NG), diesel fuel, and hydroelectric.