Seattle City Light provides electricity and electrical and conservation services to its public and private customers. It is the largest public utility in the Pacific Northwest. Public responsibility for electrical energy dates to 1890 with creation of the Department of Lighting and Water Works. In 1902, Seattle voters passed a bond issue to develop hydroelectric power on the Cedar River under the administration of the Water Department. Electricity from this development began to serve Seattle in 1905. A City Charter amendment in 1910 created the Lighting Department. Under the leadership of Superintendent James D. Ross, the department developed the Skagit River hydroelectric project, which began supplying power in 1924. Both public and private power were supplied to Seattle until 1951 when the City purchased the private electrical power supply operations, making the Lighting Department the sole supplier. The Boundary Project in northern Washington began operation in 1967 and currently supplies over half of City Light's power generation. Approximately ten percent of City Light's income comes from the sale of surplus energy to customers in the Northwest and Southwest. The current name of the agency was adopted in 1978 when the Department was reorganized.

Incorporated in 1934 and run by the Tennessee Valley Authority during the Great Depression, the Electric Home and Farm Authority allowed the purchase of electrical appliances by those families that demonstrated need based on finances. Large appliances were sold at "reasonable prices" to local power companies; families could then purchase an appliance with an Electric Home and Farm Authority loan.

(Source: TVA: Electricity for All.)