Capitol Power Plant Beginnings

The Capitol Power Plant was authorized in 1904 to support new office buildings which were then in the early planning stages. These new facilities, now known as the Cannon House Office Building and the Russell Senate Office Building, required substantial heating and electrical supplies that were to be generated remotely. In addition, the Capitol and the Library of Congress would also be tied into the new plant, as would be all future buildings constructed on Capitol Hill. With the advent of air conditioning in the 1930s, the Power Plant also supplied chilled water throughout Capitol Hill. Originally called the "Heating, Lighting, and Power Plant," the Capitol Power Plant was one of the earliest 25-cycle alternating current electric-generating facilities in the country. The original steam boilers were removed in 1923 and replaced by a second generation of steam boilers. A one-story addition was built in 1938 to house six refrigeration machines and other equipment. This was the first large refrigeration plant in the country supplying chilled water remotely. It supplied the Capitol, the two House office buildings, and the one Senate office building. (At this time the two Library of Congress buildings and the Supreme Court had their own refrigeration plants.)