Transphorm, the Goleta-based energy efficiency firm backed by $63 million from Google and other investors, has received a $3.6 million federal grant to improve solar panels.

Transphorm’s technology uses a semiconducting material called gallium nitride to drastically reduce heat waste in electronic systems. The grant from the U.S. Department of Energy went to Transphorm in a partnership with Enphase Energy, a company that makes so-called microinveters for solar panels.

In an normal solar panel, a central inverter transforms the direct current electricity generated by the panel into the alternating current used by the U.S. grid. Smaller inverters distributed among the panel could reduce the cost of solar panels. The grant asks Transphorm to make the inverter devices more efficient than silicon-based systems.

“From our headquarters in Goleta, we are solving energy waste problems for an ever-increasing base of customers,” Umesh Mishra, CEO of Transphorm, said in a release.

Transphorm is also targeting the computer server market. The power consumed by Internet servers is a major cost center for Google, which invested $20 million in the firm. The latest funding brings Transphorm’s total funding to about $66.6 million from Google, an investment fund controlled by George Soros and Silicon Valley venture capital heavyweight Kleiner Perkins Caufield & Byers.