Royal Philips Electronics has acquired yet another company offering new ways to network and control building lighting systems – Manchester, N.H.-based Teletrol Systems.

The acquisition was announced Thursday. Financial terms were not disclosed.

Teletrol makes software and hardware to control lighting and other building energy-using systems at multiple sites from a central control platform. It has installations in more than 10,000 commercial and retail sites around the world.

Now it's part of Philips' lighting electronics group, adding to the group's stable of acquisitions. The Dutch electronics giant has spent $5.4 billion on buying various lighting and energy-related companies from 2005 to 2007, and earlier this year bought Australian lighting control company Dynalite.

Much of Philips focus has been on makers of light-emitting diodes (LEDs). LEDs use a lot less energy than the traditional incandescent light bulbs, or even more energy-efficient fluorescent lights, but they're also more expensive, though startups and giants like Philips and General Electric are busy trying to change that (see Lighting the Way to Efficiency). 

Lighting uses about 22 percent of the electricity generated in the United States, so making lights more efficient is seen as a growth business. A U.S. Department of Energy study last year projected using LED in applications where they're currently seldom used - including indoor light - could lead to power savings equal to 27 1-gigawatt coal-fired power plants (see DOE Says LEDs Can Shine in 12 Markets).

That's led to a boom in venture capital investment in efficient lighting startups like BridgeLux, which has raised $71 million, and Luminus Devices, which has raised $139 million (see Luminus Closes $72M to Light Up New Applications). Other efficient light startups include Eden Park Illumination, Lumiette, Luxim, HID Laboratories and Metrolight (see Green Light post). 

But beyond making lights themselves more efficient is the idea of controlling them so they're not on when they don't need to be. That can be done for lighting systems specifically or as part of an overall building automation system that also controls things like heating, air conditioning and office IT equipment.

Adura Technologies is working on controlling lights first using its wireless mesh networking technology, though it is planning to extend its controls to other building systems (see Is Mesh the Answer for Managing Buildings?).

As for overall building automation, it's a growing field. Established players like Johnson Controls, Honeywell, Siemens, Schneider Electric, Echelon and Eaton now have competition from startups like Adura, as well as new entrants like Cisco Systems (see Cisco Rolls Out Building Management 'Mediator').

By the way, until Thursday, Teletrol's owner was Dean Kamen, the medical device entrepreneur and inventor of the Segway.

Kamen has worked with Philips on the past, recently asking the company to supply LEDs to North Dumpling Island, the island in Long Island Sound that Kamen owns and is setting up to be powered independently of the electricity grid with wind and solar power (see Green Light post).

Philips has recently launched a commercial version of another interesting energy-saving concept – light switches that can capture the kinetic energy of being pressed to send wireless signals to dim lights or turn them on and off (see Finger-Powered, Solar-Sensing Light Switches).