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By Margery Conner， Technical Editor -- EDN， 11/26/2009Despite the high light efficacy of HB LEDs (high-brightnesslight-emitting diodes)， their cost for commodity applications isstill too high for them to compete head-on with older forms oflighting， such as incandescent and HID (high-intensity-discharge)lights. However， certain applications can justify paying a premiumfor high efficiency， long life， ruggedness， andlight-color-temperature control， and these applications representthe sweet spot for HB LEDs.Read more Prying EyesOne such application is solar-powered outdoor lighting for off-grid applications. VisionaireLighting’s Solar Vision Pole lamppost is especially novel because it does not use astandard rigid solar panel that requires additional bracing for wind shear and canattract the attention of scavenging thieves. Instead， a flexible solar panel encases the post and charges four gel batteries in its base.The size of the panel and the number of batteries limit thelighting to 50W， which is a weak traditional light source but makesfor a strong， white-LED light. Six hours of charging is enough torun the light all night.The amorphous-silicon flexible Solar Flex cells produce uniform power even as the sun’s rays hit theround column of cells at an angle， easing the power-management tas