Is wind power for the birds? No one is quite sure.
Large scale wind farming for electricity is a relatively new human enterprise, beginning in the 1980s as a response to the OPEC initiated oil price hikes of the previous decade.
Alarm bells began ringing shortly thereafter as reports of large scale raptor deaths emerged in conjunction with the start up of the largest wind power experiment at the time, in Altamont, California.
Among the groups' first initiatives was the development of a protocol to standardize the work. Specifically, the committee decided on a two goal strategy of determining the risks to bird mortality associated with future wind farm development and document the number of bird fatalities linked with already existing wind farm projects.
Since that time, wind farm placements have been contingent upon four factors.
First, potential areas are studied to discover the number and types of both their seasonal and year long bird populations. Weather and other types of environmental factors potentially affecting bird populations are also taken into account.
Using this data, planners then determine which parts of the year may be more or less hazardous to the populations in question.
Finally, the information is placed into a data base in order to be able to assess how the placement of the wind farm may or may not have changed the situation.
Avian mortality evidence linked to wind farms collected over the past decade shows mixed results, pointing to the fact that facility siting rather than the wind turbines themselves plays the most important role in mortality rates.
According to a review of the studies done to date by Curry & Kerlinger, consultants to the wind power and telecommunications industries, raptor mortality is still problematic at the Altamont site, with over 5,000 turbines, the largest wind power facility in terms of total turbines. Other high numbered turbine sites, such as the San Gorgonio Pass, near Palm Springs, California, with some 2,700 turbines, record relatively few bird mortalities.
Studies of other smaller numbered turbine facilities report similar lower mortality rates.
Since the number of large scale wind farms and subsequent avian mortality studies is limited, their generalizability to future wind farm placements are also limited.
On a positive note, the studies continue and all interested environment, industry and government parties continue to consider different ways to safeguard bird populations.
The American Wind Energy Association, for example, discusses a variety of creative approaches such as changing the shape of turbine construction to make them less appealing as nesting and perching sites, varying the colors of the turbine blades and using radio frequencies that may warn or chase birds away.
Changes in wind turbine technology, increasing electricity output per turbine, promises to reduce the number of turbines necessary to produce electricity. That potentially makes more room for the birds.
© 2001-2011. Patricia A. Michaels