The Hughes Electric Company changed it name to the Fargo Edison Company in 1900. The company installed steam heating mains in the downtown area, as well as providing a 24-hour electric service. Their business grew rapidly, and competition between the Fargo Edison Company and the Fargo Gas and Electric Company became bitter. Each tried to steal each other’s customers and even each other’s poles. In 1903 the two companies finely merged to become the Union Light Heat and Power Company. In 1904 the old Fargo Gas and Electric plant was dismantled and a new gas plant was built on the site.

In the summer of 1902, the Union Light Heat & Power Company was organized to acquire and consolidate the small electric and gas companies operating in Fargo. Consumers Power Co. acquired Union in 1910. Consumers Power became Northern States Power Co., the Fargo area's current electricity supplier, in 1916, but the city's electric, gas and heating plants continued operating under the Union name until 1937, when the company merged with NSP.

The Union Light Heat and Power Company was acquired in 1910 by the Consumer Power Company, which became Northern States Power in 1916. The Union Light Heat and Power Company continued to operate under its own name until 1937 when it took the name of its owner Northern States Power.

In 1911 the Fargo and Moorhead Railway Company was acquired by the Union Light Heat and Power Company. Since its founding in 1902, the street cars current had been supplied by the power company. It was abandoned in 1937. The Union Company organized the Northern Transit Company in 1926, a bus company that was later sold in 1937.

A complete rebuilding of the downtown steam plant was completed in 1916.

The gas plant (shown right) required a rebuilding again in 1925, when the method of producing gas changed to water-carburetion.

In 1960 natural gas came to Fargo and the gas plant was shut down.

In 1938, the company invested over $1 million in improvements to their electric plant to provide additional generating capacity and to permit use of North Dakota lignite coal exclusively in the plant. In 1940, 75,000 tons of coal were used annually. At that time, NSP supplied steam heat to 160 customers in Fargo, gas service to 8,000 customers in Fargo and Moorhead, and electric service to 10,000 customers in Fargo and nearby towns. Early pictures of the electric plant can be seen here opposite the NP depot.

The electric and steam plant across from the NP depot was dismantled in 1971 after it had become obsolete with power being supplied by sources outside of the city.