Abby Arnold, facilitator of the Wind Turbine Guidelines Advisory Committee, said the panel has not received any official response to its policy recommendations. The committee was appointed by the federal government and sent its advice, along with voluntary developer guidelines, to US Interior Secretary Ken Salazar in April. The proposals include a national ecological database and incentives to encourage use of the guidelines.
"They need to be called. It's been two months. We haven't heard anything," said Arnold, who is also executive director of the American Wind Wildlife Institute, a collaboration between wind power companies and environmentalists.
Rene Braud, of Horizon Wind Energy, owned by EDP Renewables, said she had heard that the Department of the Interior would put the recommendations out for consultation close to the end of 2010. "Salazar is busy with other things," she said, in reference to the 12,000-plus barrels of oil gushing into the Gulf of Mexico each day from a sunken BP rig. The department failed to comment.
At the conference in May, the Bats and Wind Energy Cooperative (BWEC) revealed the results of an experiment in which bat kills could be reduced by an average 82%. Scientists raised the cut-in speed - the wind speed at which turbines start producing electricity - above the normal speed of 4 metres per second (m/s) on 12 out of 23 turbines at Iberdrola's 35MW Casselman wind project in Pennsylvania. But there was a slight price to pay in terms of overall economic productivity. Ed Arnett, project co-ordinator with BWEC and Bat Conservation International, said that if the curtailment were applied to the entire farm, it would result in a 0.3% loss in annual output using a 5m/s cut-in speed, and a 1% loss in annual output using a 6.5m/s cut-in speed.
Arnett also revealed preliminary results of a second BWEC study with Iberdrola, this time using devices that produce ultrasonic waves. The study at Pennsylvania's Locust Ridge wind farm found that these deterrent devices have a much weaker effect than curtailment. The deterrents reduced bat kills by at most 53% and cost about $20,000 a turbine. Arnett warned that researchers have not developed a device ready for commercial deployment. Engineers are designing a fifth-generation prototype that BCI will use for further tests at Locust Ridge this summer.
Meanwhile, preliminary results of a meta-study into bird and bat fatalities confirm the existing industry estimate that turbines cause an average of three bird kills and seven bat deaths per megawatt per year. The analysis, by Western EcoSystems Technology (WEST) reviewed studies of bird and bat fatalities carried out at 37 wind farms in 17 states and one Canadian province. The team found that the most frequently killed bird species is the horned lark, with 17% of bird kills. The most frequently killed bat species is the hoary bat, with 44% of bat kills.