Acuity Brands Lighting Inc. has agreed to buy Sensor Switch for about $205 million to boost its offerings at a time when lots of public money is set to be spent on helping homeowners and businesses conserve energy.

Sensor Switch, based in Wallingford, Conn., makes motion-controlled and programmable sensors that can turn the lights on or off depending on whether anyone is around. The concepts aren’t new, but they make good sales pitches these days when the market for improving energy efficiency is growing.

HID Laboratories in Menlo Park, Calif., for example, has developed a device to control high-intensity discharge lights that can be found in stadiums, factories and large retailers (see HID Labs and the Modern Dimmer Switch). Panasonic recently began selling a new type of florescent lamp that is equipped with a sensor that figures out how bright the room is in order to adjust the bulb’s luminance.

That’s exactly what Acuity is banking on. Lighting can use up to 40 percent of the power in commercial and industrial buildings, according to Acuity, which sells all sorts of indoor and outdoor lighting fixtures.

The company, part of Atlanta-based Acuity Brands Inc. (NYSE: AYI), expects the acquisition to help it snag more customers in the construction and building renovation markets. Acuity Brands recently bought Glendale, Cailf.-based Lighting Control and Design Inc., which creates light-dimming devices, digital thermostats and related software.

Sensor Switch, a private company founded in 1987, posted more than $37 million in revenue for the fiscal year ending Oct. 31, 2008, Acuity said.

Acuity expects to close the purchase of Sensor Switch within 30 days.