|Clark R N,|
|Davis R G,|
Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 22, 1995
Publication Date: N/A
Interpretive Summary: Wind electric generators are a new technology used to provide bulk electric power for many rural electrical needs. As with any new technology, questions arise about reliability, performance, maintenance, and repairs. This paper summaries 11 years of testing and operation of a wind electric generator of sufficient size to provide enough power for a farmstead or irrigation well. During the 11 year period, the wind turbine was "on" ready to operate 97% of the time (availability) and actually ran producing power 61.6% of the time. The actual run hours were 55,716 hours. The amount of electricity generated was 839,699 kWh which represents an average of 6,700 kWh per month, more than enough to operate many farmsteads. Early in the test program, several problems were encountered with the control system and a cracked tower-leg caused significant down time. Most of the down time during the last half of the test period (5 yrs) was caused by icing on the rotor blades requiring the unit to be shut off to reduce the consumption of electricity.
Technical Abstract: A 13.4-m rotor diameter wind electric generator was installed in the Southern Great Plains at the USDA Conservation and Production Research Laboratory, Bushland, TX in May 1982 and operated continuously through June 1993. The original turbine was a 240 V, single-phase generator with a rated capacity of 25 kW. This prototype unit was changed to a three-phase, 40 kW generator production unit in 1984 and later that year, a three-phase, 480 V generator rated at 60 kW was installed. All units used the same rotor size and design. The wind turbine ran for over 55,700 hours during the 11 years and produced almost 840,000 kWh of electricity. The 55,700 operating hours represents 61.6% of the time since installation. Although several component failures occurred during the testing period, the wind turbine was available 97% of the time. The 3% down time was estimated as 1% for routine maintenance and service, 1% for repair of component failures and 1% for weather related events, mainly icing.