NREL’s Owen Roberts reports that FloWind’s prototype 100 kW Darrieus wind turbine installed in early 1982 is still standing inoperative near Ellensburg, Washington.
FloWind, a creation of Flow Industries in Kent, Washington, developed a series of Darrieus or Vertical-Axis Wind Turbines (VAWTs) in the early to mid 1980s. Their first turbine, a prototype of their 17-meter diameter model was installed on the Black Angus Ranch 12 miles northwest from Ellensburg.[1]
The two-blade VAWT is just off Thorp Prairie Road, east of I-90. It can clearly be seen on Google Maps at coordinates: 47°06’03.7″N 120°44’59.3″W.
Roberts first noted the turbine in 2014. He says that the machine has been standing idle—that is not in service–since at least 1994 when it first became visible on Google Maps. Apparently, the VAWT has been derelict or inoperative at least 30 years–if not longer.
FloWind built two commercial models: the 17-meter, and a later 19-meter. The 17-meter used a rotor 17-meter in diameter and 23-meters in height. According to the CEC’s 1986 Wind Project Performance Reporting System Annual Report, it was rated at 143 kW at a wind speed of 44 mph (19.6 m/s). The phi-configuration Darrieus swept 206 m². The 19-meter turbine used a rotor 19 meters in diameter and 25 meter in height. It was rated at 250 kW at a wind speed of 38 mph (17 m/s). The 19-meter turbine swept 340 m².[2]
Both the 17-meter and 19-meter had high power ratings relative to their swept area even for the day, giving the 17-meter a specific power of 550 W/m² (1.8 m²/kW) and the 19-meter 735 W/m² (1.4 m²/kW).
FloWind also installed one 25-meter diameter prototype and two EHD (Extended Height to Diameter) prototypes at their site on Cameron Ridge in California’s Tehachapi Pass.
Altogether, FloWind installed 512 commercial turbines and four prototypes for a total of 516 Darrieus turbines in Washington state and California.
Though FloWind went bankrupt in the late 1980s, its wind turbines continued in operation until 2004 when production from the last machines ceased. In 2010 the remaining FloWind turbines in the Altamont Pass were finally removed in a repowering project.[3]
The turbine on Thorp Prairie road is likely the last remaining FloWind Darrieus turbine in the world and should be in a museum somewhere.
For more see FloWind: The World’s Most Successful VAWT (Vertical Axis Wind Turbine).
[1] Paul N. Vosburgh, Commercial Applications of Wind Power (New York : Van Nostrand Reinhold Co., 1983), page 68.
[2] “Results from the Wind Project Performance Reporting System: 1986 Annual Report” (Sacramento, California: California Energy Commission, January 1988), https://web.archive.org/web/20150906080857/http://www.energy.ca.gov/wind/documents/1985-1993_reports/WPRS_1986_P500-87-019.pdf. And Paul Gipe, Wind Energy for the Rest of Us: A Comprehensive Guide to Wind Power and How to Use It (Bakersfield, California: Wind-works.org, 2016), page 148. Note that the rating is reversed for the 17-meter and 19-meter and the rated power for the 17-meter is 143 kW in the CEC’s WPPRS.
[3] Erik Möllerström et al., “A Historical Review of Vertical Axis Wind Turbines Rated 100 kW and Above,” Renewable and Sustainable Energy Reviews 105 (May 1, 2019): 1–13, https://doi.org/10.1016/j.rser.2018.12.022, page 6.
