About Idaho Falls Power
The City of Idaho Falls has operated a municipal electric generation system since 1900. The first generator, power by water from a canal, originally provided electricity just for street lights. The current system now generates and distributes electricity for a multitude of uses to all residents residing within the corporate city limits of Idaho Falls. The system is operated by the City’s Electric Light Division, which does business as Idaho Falls Power.
The current generation system is composed of two main projects--the Bulb Turbine Project and the Gem State Project. The Bulb Turbine project replaced or augmented three hydroelectric facilities constructed along the Snake River between 1912 and 1940. The plants at the original Upper and City sites were virtually destroyed by the Teton Dam collapse and flood in 1976 and required replacement. The Old Lower Plant facility did not sustain as much damage and was retained. The new bulb turbine facility was constructed adjacent to it.
Construction began in 1978 and was completed in 1982. The Bulb Turbine Project was one of the first in the United States to use the European technology of placing the turbine-generator entirely within a horizontal water passage. The generator is enclosed in a water-tight seal “bulb” and connected to a downstream runner by a horizontal shaft. The advantage of using this technology over the more common vertical-shaft turbines, is that it better utilizes the relatively low-head (water height) in the stretch of the river around Idaho Falls.
The available head at each of the three sites is approximately 19 feet, which is low compared to most utility-scale hydroelectric projects. Each of the three plants channels up to 6000 cubic feet per second of water through the turbines to produce up to 8000 kilowatts of energy each. The total production from the three plants sites produces approximately 100 million kilowatt-hours of electricity annually.
The Gem State Plant is nearly as large as the Bulb Turbine Plants combined. It was constructed at an abandoned hydroelectric site south of town on the Bonneville-Bingham County line. Construction began in 1985 and the plant was completed in 1988.
The power house contains one vertical Kaplan Turbine with an installed capacity of 22.6 megawatts operating under a 43 foot head. Its 40 foot high, 3600 foot long earth-fill dam, impounds a reservoir of 5,000 acre-feet with a surface area of 305 acres. This has become a popular area for fishing and boating for area residents. The plant produces approximately 120 million kilowatt-hours of electricity annually. Total output from all the plants produce about 30% of the annual electricity requirements of Idaho Falls customers.
For more information about hydropower, go here for the Foundation for Water and Energy Education's website.