ARLINGTON — An earthquake has struck. A snowstorm has downed power lines. Streets are blocked by debris.

When that occurs, backup generators that produce electricity for homes, hospitals and command centers switch on.

But generators that run on gasoline or diesel can be difficult to refuel if roads become impassable.

One solution? Construct a micro electrical grid, powered by renewable energy sources that operates independently from the main power grid and can supply power during an emergency.

That’s the idea behind a $9.5 million project expected to go on line in 2020.

The Snohomish County Public Utilities District broke ground this week on the new Arlington Microgrid and Clean Energy Technology Center near the Arlington Municipal Airport at 17601 59th Ave. NE.

The microgrid is supported by a $3.5 million grant from the Washington Clean Energy Fund, PUD spokesman Neil Neroutsos said.

“This project is another step forward in modernizing our electric grid,” said Brian Bonlender, director of the Washington State Department of Commerce, which manages multiple grant and loan programs offered through the state’s Clean Energy Fund.

When completed, the sunlight-fueled microgrid will have one megawatt hour of storage capacity, enough to power 700 homes for an hour.

The goal is to bring the Arlington microgrid online by 2020.

Plans also are afoot to locate an Arlington PUD office next to the microgrid by 2022.

During non-emergencies, the solar panels will feed the power they generate into the PUD’s larger network.

In an emergency, the microgrid could be disconnected from the main grid and used, for example, to power the Arlington PUD office so the PUD could direct power restoration efforts from that location.

“If the grid were to go down in a disaster, this building and facility would play a very important part of the PUD’s response,” project manager Scott Gibson said.

“The Arlington Microgrid could sustain the local office in the meantime,” Gibson said. “Also, its proximity to the Arlington Airport would be key in an emergency.”

The microgrid project will include a Clean Energy Technology Center to demonstrate microgrid technology and other renewable energy options.

Janice Podsada; jpodsada@heraldnet.com; 425-339-3097; Twitter: JanicePods.