California Maritime Academy wind resource study, 1982. u-v-w, direction vane, and cup anemometer. Tehachappi, California wind farm 1984. Meteorological Tower data recording, Tehachappi Mountains, California, 1985. Pachaco Pass, California, 1985. Tilt up meteorological tower installation, Tehachappi Mountains. Multiple u-v-w sensors monitor flow profile near Pajuela Peak, Tehachappi, California, 1986. Palm Springs, 1987. Palm Springs, 1987. Vehicle Testing starting in 1988 Wind Turbine power monitoring, Bonus Wind Turbine, Tehachappi, California, 1988. Vehicle Testing in 1997 The late Thomas Lockhart reviewing the vehicle test process, NREL study, 1997. Norris Hill, Montana, 1998. Vehicle Testing in 2002 Wind Tunnel 1A, Davis, California, 2005. Wind Tunnel 2B, Davis, California, 2007. Test section close up, Wind Tunnel 2C. NSP Windset, Minnesota.

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History

Otech Engineering, Inc. was founded in 1981 as a company supporting renewable energy resource development as part of creating a sustainable energy future. The company history includes involvement in solar energy applications, energy conservation measures, and consultation on energy related governmental policy. Most of the company’s experience has been in support of the wind energy industry, with specific emphasis on wind resource development and related instrumentation and measurement technology. For the wind industry, Otech has performed activities including:

1. field services such as meteorological tower installations, wind turbine monitoring systems, scheduled maintenance checks, on-site data collection, and site inspections;
2. consulting services such as wind resource assessment, engineering and economic analysis, and data quality management and analysis;
3. and anemometer calibration services.

Since 1996, Otech has focused primarily on calibration testing for anemometers used in the wind energy industry. This direction in the company business plan was motivated by a 1988 private field study investigating the performance of two-bladed, downwind turbines installed in complex terrain. The study required wind profile measurements over a mountain ridge, where Otech installed five multi-level towers with u-v-w propeller and cup anemometers.

In order to certify the wind speed readings, the anemometers were calibrated in a wind tunnel facility at University of California, Davis. Unexpectedly, there was an implausible 7% variation in the wind tunnel calibration results between each sensor. Otech conducted a secondary calibration with the same sensors on a vehicle test rack, which revealed only a 1% to 2% variation in calibration results. This variability between results, test methodologies, and test facilities was primarily due to non-standard test procedures and recognized a need for the standardization of anemometer calibration. Thus, Otech developed a calibration test program using a moving vehicle and provided this service from 1988 to 2005.

While Otech continued the vehicle test program, other test facilities were also being developed and standards organizations established and began to institute anemometer calibration protocols. Based on the recommendations from standards organizations, anemometer calibrations are to be performed in a controlled wind tunnel facility. Thus, in 2005, Otech retired the vehicle test program and established a wind tunnel test laboratory in Davis, California.

With the wind tunnel test laboratory, Otech progressed to a higher level of test quality and accountability. Due to industry demands for calibrated anemometers, Otech expanded to a second wind tunnel in 2007, and a third wind tunnel in 2010.