Roxboro Steam Station (IMAGE) Duke University Caption The Roxboro Steam Station, a four-unit, 2,422-megawatt coal-fired Duke Energy plant in Semora, N.C., is one of the largest power plants in the United States. It began operation in 1966, with additions in 1973 and 1980. Credit Heileen Hsu-Kim, Duke University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.