Green Mountain Power has begun constructing a 2-MW solar microgrid on a city landfill in Vermont. The unit is designed to store power during storms for an emergency shelter at Rutland High School.

The $10-million Stafford Hill Solar Farm, which broke ground on Aug. 10, is the first project in the nation to establish a micro-grid powered solely by solar and battery backup, with no other fuel source, the U.S. Dept. of Energy says.

Stafford Hill includes 7,700 325-watt solar panels on a ballasted ground-mounted system with no below-grade foundations, according to Green Mountain Power, Colchester, Vt. The 2-MW system includes 4 MW of battery storage for solar generation, which will benefit customers and, in an emergency, allow the disconnection of an entire circuit from the grid while still providing power for the shelter.

The project received about $250,000 from DOE and another $35,000 from the Vermont Clean Energy Fund. Dynapower Corp. is manufacturing and designing the power inverters and procuring the batteries, and groSolar is managing construction, says Josh Castonguay, director of strategic products and services at Green Mountain Power. The project is using both fast- charging lithium-ion batteries and longer-discharging lead-acid ones.

Gov. Peter Shumlin (D) in a statement said there is a clear need for self-sustaining microgrids that can continue to provide power during storms and when there are widespread outages.

"This project focuses more on the local grid—it's not a big bulk transmission project," Castonguay says. "The goal is to duplicate the microgrid around the state, and, separately, we're looking at developing energy storage on a smaller distributed scale on the grid to assist customers and first responders."