Did you know that newly hatched turtles need a dark night sky in order to orient toward the ocean? Newly hatched turtles follow the light, and that light is supposed to be the moon reflecting off the ocean. Because of light pollution, helpless turtles have been found wandering landward or near busy boardwalks instead of the ocean where they belong.
Hatchlings are confused by the white light provided by lighting in housing units, outdoor lighting and even street lights, which are somewhat away from the water. The solution until now has been either shut the lights off which doesn’t work for humans, or use amber lamps inside luminaires.
Recently I, Dr. Bulb, read about a team of researchers based in Mexico and Japan who believe they have found a solution to help solve the problem of light pollution! A solution different than shutting the lights off or using amber lights would be fantastic for all.
The study, which appeared in the open-access journal Optics Express, examines the current problem of conventional street lamps which scatter up to 20% of their energy horizontally or vertically. Fortunately, researchers have come up with a new type of LED-powered street lamp that would only illuminate the desired section of a road.
Light pollution doesn’t only affect turtles. Migratory birds veer off course, while other animals have shown signs of disrupted circadian rhythms. And for humans like me, Dr. Bulb, it obscures views of stars, wastes energy, disrupts sleep and makes it difficult for drivers to see!
The researchers say that even the best LED street lamps on the market still direct about 10% of their energy horizontally or vertically, but they claim their invention could reduce the amount to just 2%. Although they’ve yet to create a working prototype, the proposed lamp would use three features to limit light to a predetermined rectangular shape to cover the road.
A Total Internal Reflection (TIR) lens is fitted over a cluster of LEDs in order to focus the light so the rays are parallel to each other in one direction, instead of intersecting.
The TIR lens with LEDs is mounted inside a cavity that helps “recycle” light which have failed to travel the desired path.
Each lamp is covered in a microlens sheet diffuser that filters unwanted glare.
One of the most exciting parts about this discovery is the drastically reduced energy consumption, requiring between 10 to 50% less power than current LED street lamps!
I am hoping this prototype succeeds. The researchers hope to complete it by October 2013. If the prototype is successful, it needs to be brought to the attention of local authorities as a necessary investment like dark sky compliant products and energy saving LED wallpacks or LED troffers. With the innovative new design’s efficiency, reduced energy cost, and turtle-saving abilities, it’s an easy sell for Dr. Bulb.
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