There's enough energy in your fingertip to save a bundle on wiring.

That's the premise behind the Airwave lighting controls from Ledalite Architectural Products. The subsidiary of Royal Philips Electronics says its new light switches can capture the energy of being pressed to send wireless signals to turn lights on and off. Hold the switch down, and it will dim lights.

By slapping the switches (now available only with an order with Ledalite lights) onto any available surface, builders can save the hassle of tearing open walls to string new wiring for lighting retrofits, or up to 30 percent of the copper wiring normally required for a new facility, the company says.

And to save energy automatically, Ledalight has separate wall-mounted light sensors that can capture energy with tiny photovoltaic cells and sense how much sunlight is in a room to dim or turn off lights accordingly. 

Both devices use technology from EnOcean, a German company that specializes in energy harvesting – capturing power from the environment. Its kinetic energy capturing technology is also being used by Verve Living Systems, which demonstrated its own wireless light switch at the West Coast Green building show in September. (For video of how the switches work, click here). 

EnOcean, a Siemens spinoff, has also developed ways to capture energy from heat differentials, for example, between a hot pipe and the cold outside air. It's one of several companies working on applying energy harvesting technologies and wireless communications to a variety of products aimed at markets from the military to households (see Tiny Batteries Get Better). 

Hampton, Va.-based AdaptivEnergy, for example, makes devices that harvest energy from vibrations. Pittsburgh-based PowerCast makes devices that capture energy from radio waves – something Intel also is working on  (see Intel's Power Play: Charging Gizmos in the Air). 

But as far as contractor-friendly systems, Ledalite is the first lighting company to come out with a system that integrates wireless battery-free light switches and sensors with the transceivers that control lights, said Lance Howitt, the company's marketing manager. 

The switches cost about $80 and the light sensors cost about $150 each, he said. As far as how those costs would compare to a traditional, wall-mounted and wired switch, that all depends on the size of the job and the complications involved with wiring it, versus going wireless, he said. 

As for the environmental benefit of using less wiring – and the efficiency benefits of saving power by using light sensors to dim lights – that's up to the building owners to measure.

But Wednesday's news of Acuity Brands Lighting's $205 million purchase of Sensor Switch – which makes motion-detecting sensors to switch lights on and off – would indicate that energy saving technologies are high on the list of priorities for lighting manufacturers. 

And based on the interest Philips and other lighting giants have shown in startups promising more energy efficient lighting systems, it would appear that making more efficient lights – which consume about a fifth of the electricity in the United States – will be a growth business (see Lighting the Way to Efficiency).