Fluorescent lighting is more energy efficient than traditional incandescent bulbs, but there’s one area in which they can’t compare. Unlike a standard light bulb, a fluorescent light can’t easily be dimmed by simply reducing the power to it.

Lumenergi makes “ballasts” for commercial fluorescent lightning, which can dim the lights during the bright portions of the day, saving money. The company has put several years into researching the best way of building fluorescent dimmers, and is now beginning to sell them.

The $7.5 million funding is tranched, and the company has so far received $3 million. It was provided by Low Carbon Accelerator and Noventi. Lumenergi, formerly known as Luminoptics, is based in Sparks, Nevada.