WIND, BIRDS AND SOLUTIONS

On radar: Solutions to sidestep avian mortality; A clutch of vendors are touting radar as a way of cutting the worrying cull that wind farms inflict upon bird and bat species. Will this expensive remedy work, though?
Jason Deign, December 15, 2011 (Wind Energy Update)

"…DeTect has installed its Merlin avian radar system at 40 wind farms worldwide. And Robin Radar of the Netherlands now offers a similar system…A radar tracks any sizeable flying object and when it gets close to a wind farm the operator has the option of switching off nearby turbines or issuing a deterrent such as an alarm call.

"The systems are even capable in some cases of distinguishing different types of birds based on characteristics such as wind beat frequency. DeTect has a product called Vesper to detect bats and the insects they feed on…The radar companies point to the success of their technology in reducing bird strikes in the aerospace industry and elsewhere."

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Even the companies behind them admit it is still a little too early to tell…[O]nly a quarter of the Merlin systems currently deployed are actually used in combination with a wind farm supervisory control and data acquisition (SCADA) system for mitigation purposes. The rest are only used for monitoring, often as part of site evaluations…[and] DeTect’s smallest system sells for $500,000 and Robin Radar’s systems cost…quite a few hundred thousand euros…[so] wind farm owners will likely want to know what alternatives are available…

"…DTBird camera-based visual bird tracking system sold by Liquen of Spain…comes with an automated acoustic alarm or turbine-shutdown feature and works on a turbine-by-turbine basis…This can be configured to respond only to particular types of birds, such as endangered raptors, and costs less than 1% of a turbine’s value to install and less than 1% of its annual operating profits to maintain…A visual system has the advantage that its effectiveness, or otherwise, is captured on film…[L]ess than 5% of birds stray into the rotor path after the alarm has sounded…However, DTBird does not work at night (although a more expensive night-vision model is under development) and, as with radar systems, there is no peer-reviewed data to support its efficiency; only a few turbines in Spain and Italy are currently equipped with it…"