A wind-turbine test site in Østerild, Denmark includes seven wind-power generators that stand 250m high, along with two equally tall lighting masts that ensure that pilots can see the potential obstruction day and night. The masts include Obelux Oy solid-state lighting (SSL) mounted at 83m, 167m, and 250m, and the choice of LED lighting ensures long-life operation with no maintenance and low energy usage.
The masts and lighting were installed by YIT A/S. "Obelux LED obstruction lights were chosen due to their extremely long maintenance free lifetime," said Niels Riss of YIT A/S. "LED lights will save us a lot of unplanned site visits compared to conventional light sources, and thus, decrease the total cost of ownership." Obelux warranties the lights for five years.
Fixtures are mounted on three sides of the mast with each delivering a 120° beam providing. The installation provides the 360° coverage required by the International Civil Aviation Organization.
The flashing lights are at their brightest during the day so that pilots can clearly see the obstruction even in sunlight. During daylight hours, each fixture delivers 200,000 cd and 120,000 lm.
A ground-level control systems drops the light level to 20,000 cd during twilight hours and even further to 2000 cd at night. The system includes a GPS to synchronize the operation of all lights and accurate changes in light level in terms of time of day.