History of District Heating in the United States

| Chronological List of District Heating Systems in the United States |

District Heating in Washington, DC

The Washington Gas Light Co. built a district energy plant to serve the new Watergate complex in Washington. The plant opened in 1965. The land on which the complex was built was formerly the site of gas works owned by the Gas Light Co.

The system was sold to Vicinity Energy in 2019.

References
1965 "Gas Chosen for Heating and Cooling Watergate Project," Gas Age 132:60 (1965)
WASHINGTON, D.C.—One of the world’s most unusual air conditioning systems is now being placed in one of the world’s most unusual and luxurious apartment-hotel-office building communities.
Watergate, a $66 million city within a city, will be heated and cooled from a 4000-ton-capacity central plant furnished and operated by Washington Gas Light Co.—reportedly the first public utility to sell chilled water and steam to what is essentially a residential project. When completed in 1968, Watergate will contain approximately 1000 cooperative apartments.
Washington Gas Light’s plant is in a sub-basement of Watergate East.
Chilled water and steam will be distributed to all buildings through insulated pipe in trenches under the common auto parking levels that connect the structures.
Three 1000-ton absorption refrigerating machines and three 40,000 lb/ hr steam boilers are the core of the system. Another 1000-ton absorption unit will be installed as the entire project nears completion. The plant will begin operation this summer when Watergate East is opened.
The system was designed around three steam turbines that drive the primary chilled water and condenser water pumps. The turbines will use 275-lb steam, reducing it to 100 lb for heating and to 12 lb to produce cooling through the absorption machines.
Pipe ranging in size from 12 to 20 in. will distribute 12,000 gpm of 44°F water and 100-lb steam to pumps and heat exchangers in each building. Btu meters will determine the amount of cooling and heating used, and billing will be based on commodity and fixed demand.
Eight low-silhouette cooling towers will be placed on the roof of the centrally located Watergate office building. Two towers will be winterized for year-round operation.
Each building will be equipped with a four-pipe distribution system to provide year-round climate control in each apartment. Zoned controls will make it possible to vary temperatures between living and sleeping areas. Fan-coil terminal units will range from built-ins to low silhouette units for balcony access.

1968 Promotional Practices by Public Utilities and Their Impact Upon Small Business: Hearings, Ninetieth Congress, Second Session, Pursuant to H. Res. 53
Page 96: Prior to and culminating in its involvement in the Watergate Project, which is highly questionable and requires the strictest attention of the Public Service Commission before approving the Gas Company's pending application, the heating and air conditioning plant installed in Watergate was purchased, financed and installed by the United States Leasing Corporation, which in turn leased the said plant to the Gas Company, upon the Company's personal guarantee to meet the terms of the lease in the amount of $2,000,000 over 25 years, which, in effect, secured the total investment of United States Leasing Corporation. The developers of Watergate hence were not required to make the normal capital investment generally borne by most project developers for heating and air conditioning equipment; the Gas Company's offer to provide such an arrangement to the Watergate developers was therefore an inducement to cause said developers to use gas service as a fuel for heating and cooling, as distinguished from fuel oil or electricity.