Delft University of Technology is at the cutting edge of energy saving outdoor lighting. In response to a competition challenge, Chintan Shah worked to create an outdoor lighting system comprised of LED lighting, motion sensors and wireless communication. Since these are street lights, they never fully go out, but instead dim to about 20% of standard power. When someone approaches, they light up. Any lighting failures are wirelessly communicated to a control room, which helps keep maintenance less expensive and more efficient.
This kind of system is more than a normal homeowner would need, but it is based on the same technology used by home outdoor lighting systems. To keep energy usage and costs down, the use of motion sensors are a very good idea. Additionally, they keep the lights on only when needed, also reducing the incidence of light pollution.
Study cited from Delft University of Technology (2011, July 13). Intelligent street lighting saves up to 80% on energy. ScienceDaily. Retrieved July 18, 2011, from http://www.sciencedaily.com /releases/2011/07/110712093623.htm