Redwood Systems, a company that installs LED, or light-emitting diode, systems in commercial buildings, has raised $15 million in equity. Battery Ventures, U.S. Venture Partners and Switzerland-based Index Ventures participated in the round, according to a filing with the SEC.

Based in Fremont, Calif., the company powers all lights in a building through a network system. By converting buildings from fluorescent or other lighting to LED systems, Redwood Systems can help businesses conserve energy.

Founded in 2008, the company first raised $4 million in October of that year.