LED Street Light Ac 5-50W 2700K and 3000K LEDs are mostly used for indoor lighting. The initial cost of LED street lighting is high and as a consequence it takes several years for the savings on energy to pay for that. The high cost derives in part from the material used since LEDs are often made on sapphire or other expensive substrates LEDs also offer much greater control over where the light falls. This means they can often meet the same illumination requirements as conventional streetlights while emitting much less light  thus reducing even further any short-wavelength content. Myth: Street lighting should never emit any short-wavelength light