There is a reason astronomers prefer to set up their largest telescopes in high areas that are scarcely populated: light pollution from large urban agglomerations prevents them from getting a clear view of the sky. Researches have now come up with a new LED streetlamp design that has the potential to considerably lower light pollution.
The new lamp is designed to produce a concentrated beam that shines only where needed, unlike current street light systems which leak the light into unwanted areas, thus wasting energy and obscuring views of the sky and stars. This is due to the fact current street lights generally use sodium or mercury lamps that produce non-uniform light patterns, scattering up to 20% of their energy.
But the research team, based in Mexico and Taiwan, believes that the waste of energy can be prevented by controlling the light beams. The research was based primarily on LED lamps as their light is easier to direct, since it is emitted from a smaller area. While LED streetlamps already on the market waste about 10% of their energy by directing it vertically or horizontally, the new design can significantly reduce the waste to only 2%, the scientists say.
The joint Mexico-Taiwan research project has three major features ensuring that the light will be directed to only the needed areas: a special lens for total internal reflection which allows all rays to travel parallel in a single direction, a reflecting cavity for the LED lamps which can reuse any errant rays, and a diffuser to eliminate the glare. This design will allow the new streetlamp system to project a uniform beam of light over any given area.
Tests also indicated that the new system can reduce energy consumption by 40-60 percent. The researchers are working on a prototype, which they plan to have ready by October, in order to begin practical installations of the new system next year.
[Image via Gizmag]