Ames Hydroelectric Generating Plant

Ames Hydroelectric Generating Plant
Ames Hydroelectric Generating Plant in 2011
Location	Ames, Colorado, United States
Coordinates
Status	Operational
Commission date	1891
Owner(s)	Xcel Energy
Thermal power station
Type	Hydroelectric
Power generation
Units operational	1
Nameplate capacity	3.75 MW

Overall view of Ames plant, early 20th century

The Ames Hydroelectric Generating Plant, located near Ophir, Colorado, was the world's first commercial system to produce and transmit alternating current (AC) electricity for industrial use. It is now on the List of IEEE Milestones.

In the summer of 1890, Westinghouse Electric supplied the station's generator and motor. They were installed in the winter, and from Spring 1891 provided alternating current electricity that was transmitted 2.6 miles (4.2 km) to a motor-driven stamp mill at the Alta Mine. The mill was at the time at risk of shutdown from lack of timber fuel for its existing steam mill. The AC power plant effort was financed by L.L. Nunn.

Interior view, 1895 Ames powerhouse

The generator is driven by a six-foot Pelton wheel under a 320-foot (98 m) head. Its 100 horsepower (75 kW) Westinghouse single-phase generator was the largest then manufactured, generating electricity at 3000 volts, 133 Hertz, single-phase AC. Voltmeters and ammeters were of both the solenoid and gravity balance types. The transmission line was built from Western Union cross-arms with insulators carrying two bare copper wires. Total wire costs were about US $700, about 1% of the cost estimated for a direct-current line. The entire plant required 15 to 20 attendants for its continuous operation.

The alternating current was proven to be effective as it was transmitted two miles (3 km) at a loss of less than 5%.

2010 exterior view of Ames Power Station, built 1905.

The station was built during the "War of Currents" between Westinghouse and Thomas Edison as to whether alternating current or direct current electric power would prevail, and its success led to adoption of alternating current at much larger plants at Niagara Falls (Adams Power Plant in 1895) and its eventual dominance worldwide.

The Ames plant became part of the Nunn’s Telluride Power Company which would later become part of Western Colorado Power Company, formed as a wholly owned subsidiary of Utah Power and Light. Public Service Company acquired the plant with other Colorado Ute properties in 1992.

The 1905 power house is still in service for Public Service Company, a subsidiary of Xcel Energy, with two Pelton wheels powering a single 1904 General Electric generator, with output of 2,400 volts, and 1,082 amperes at a speed of 225 R.P.M.

Significance in the history of the electrical energy supply

The Ames Hydroelectric Generating Plant power plant is the oldest hydropower plant which produces and transmits alternating current for industrial purposes, operating machinery.

The oldest hydroelectric power plant supplying a commercial transmission system for alternating current is the power plant Thorenberg near Lucerne in Switzerland. The plant started operation in May 1886 and fed 1,800 volts to a nearly 3 miles (4.8 km) long transmission line. It was transformed to 100 volts to illuminate some hotels and restaurants in the downtown area of the city.

A few months before the Thorenberg plant opened, the first alternating current distribution network with two voltage levels started operation in Great Barrington, Massachusetts at March 20, 1886. The power for this system was generated by a steam engine.

External links

• Ames Hydro Plant description, with photos, movies, & links
• History and photos of Ames Hydroelectric Plant, at Historic American Engineering Record