County officials are pleased with the performances of four wind turbines installed in early 2011 at Riley County Public Works. Though some models are more reliable than others, they said the turbines have been money-savers for their various facilities.
The turbines, in varying sizes, were installed last year at the county shops site near the intersection of Tuttle Creek Boulevard and Marlatt Avenue. They range in height from 45 to 121 feet, and in blade diameter from 12 feet to 69 feet.
Based on a recently released analysis of energy generation over the last six months of the year, officials said the most reliable wind turbine has been the largest of the four. The Northern Power 100 is a 100-kilowatt turbine that is 121 feet tall with 69 feet long blades. The turbine generated 95,868 kilowatt hours of energy from July to December 2011, enough to power 20 to 30 houses, Rod Meredith, assistant director of Riley County Public Works, said.
The turnkey cost for the turbine is $575,000 and Meredith said payback is about 12 years.
He said though the environmental friendliness of wind turbines is a positive, the primary goal of installation is to reduce electricity costs. Together, the four turbines — which help power the approximately 96-acre site — will save the county about $40,000 a year.
Ruth Douglas Miller, associate professor of electrical and computer engineering and director of K-State’s Wind Application Center, said it’s the really large turbines, particularly the industrial-sized ones found on the expansive farms in western Kansas, that have the quickest payback. Those turbines are about 180 feet tall, with blades that are 130 to 140 feet long.
Miller said for those Western farmers, the turbines are very practical, noting also that farmers receive lease payments per turbine per year. In Riley County, she said, smaller turbines generally have a payback time of about 20 years, making wind turbines less cost effective for the small farmer looking to power their own farm. Meredith said the recommended turbine to power a small farm would cost about $150,000.
Miller said turbines generate electricity without increasing in cost over time and without adding pollutants to the atmosphere, which is why she recommends that the state take advantage of what could be a major industry for Kansas.
She said Kansas is the second windiest state for easy to capture energy, and energy from wind turbines could be exported much like natural gas, creating jobs and money for the state.
The four turbines at the Riley County Public Works site were installed through a grant from the U.S. Department of Energy, designed to encourage communities throughout Kansas to make a shift toward a more energy-efficient economy.
The Northern Power 100 is the largest turbine at the site. The smallest is the Skystream 3.7, a 2.4-kilowatt turbine that is 45 feet tall with 12 feet long blades. It generated 1,303 kilowatt hours between July and December 2011 and costs $25,000. Meredith said it could power half of a house. An 80-foot tower with 31-foot diameter blades generated 10,505 kilowatt hours during that same period, while a 100 foot tower with 44 foot diameter blades generated 19,516 kilowatt hours of energy.
Meredith told county commissioners last week that of the four turbines, the largest showed potential for amortizing its installation cost in a reasonable time period.
Meredith said the program is designed to teach cities, counties, colleges and agribusinesses how to reduce energy usage and promote renewable energy technologies. In addition to installation of the wind turbines, the $1.2 million grant included four solar energy systems and a 200,000 BTU waste-oil heater.
Each installed technology will be analyzed in a case study, Meredith said, with the wind turbines being the first to be studied.