HONOLULU » Hawaii regulators have approved a deal allowing Maui Electric Co. to buy an additional 21 megawatts of wind energy from Kaheawa Wind Power.

The agreement approved by the state Public Utilities Commission calls for Kaheawa, a subsidiary of Massachusetts-based First Wind, to sell as-available renewable energy to Maui Electric and pre-determined prices over 20 years.

Kaheawa already sells Maui Electric power from its existing windmills above Maalaea. The new agreement enables Kahawa to sell Maui Electric power from 14 new windmills the company plans to build as part of a wind farm expansion.

The companies said in a joint statement Tuesday the expanded wind farm will produce enough energy to power the equivalent of 20,000 Maui homes.