Researchers Seek to Reduce Bat Deaths from Wind
Turbines
EERE Network News - 11/6/08
The Bats and Wind Energy Cooperative (BWEC) announced in mid-October that it
has begun testing a procedure to stop wind turbines during low-wind
conditions to avoid killing bats. Bat deaths from wind turbines are a
relatively recently discovered phenomenon, and although they are not fully
understood, recent studies have suggested that most bat deaths occur on
low-wind nights when the turbines are producing low amounts of power, but
may be rotating near their maximum speed. Based on that finding, Iberdrola
Renewables has agreed to shut down the turbines at its Casselman Wind Power
Project in Pennsylvania during low-wind conditions. The experiment will
provide information on how the new operating procedure will effect both bat
deaths and power production at the 34.5-megawatt facility, which is located
southeast of Pittsburgh. The BWEC is a unique alliance of Bat Conservation
International, the American Wind Energy Association (AWEA), the U.S. Fish
and Wildlife Service (FWS), and DOE's National Renewable Energy Laboratory.
Iberdrola Renewables isn't just helping out the BWEC experiment; the company
has also committed to responsibly developing wind power while addressing
wildlife concerns. Last week, Iberdrola released a company-wide Avian and
Bat Protection Plan, modeled on a similar plan to address the impacts of
power lines on birds. Preparing in consultation with the FWS, the plan
establishes a process for contact with government agencies and
non-governmental organizations early in the site assessment stage of new
wind power projects. It also includes policies for pre- and
post-construction monitoring and other measures to reduce and mitigate bird
and bat deaths.
While bat deaths remain poorly understood, a recent study by the University
of Calgary suggests that it's not an actual impact with wind blades that
kills bats, but rather the effects of the pressure drop caused by the moving
blades. Large numbers of migratory bats are being killed by some of the
turbines in southern Alberta's wind facilities, and a study of the dead bats
at one of those sites found that the bats suffered severe injuries to their
respiratory systems consistent with a sudden drop in air pressure, a
condition known as barotrauma. While only half of the dead bats showed signs
of being struck by wind turbine blades, 90% had injuries consistent with
barotrauma. The study was published in the August 26 online edition of
Current Biology. |