Solar Companies Seek Ways to Build an Oasis of Electricity

November 21, 2012 by  
Filed under Green Energy News

Despite the popular perception that installing solar panels takes a home “off the grid,” most of those systems are actually part of it, sending excess power to the utility grid during the day and pulling electricity back to run the house at night. So when the storm took down power lines and substations across the Northeast, safety systems cut the power in solar homes just like everywhere else.

“Here’s a $70,000 system sitting idle,” said Ed Antonio, who lives in the Rockaways in Queens and has watched his 42 panels as well as those on several other houses in the area go unused since the power went out Oct. 29. “That’s a lot of power sitting. Just sitting.”

Yet there are ways to tap solar energy when the grid goes down, whether by adding batteries to a home system or using the kinds of independent solar generators that have been cropping up in areas hard-hit by the storm.

In the Rockaways, where nearly 14,000 customers still had no power as of Monday morning, volunteers set up a makeshift solar charging station between a car roof and a shopping cart. A multipanel, battery-tied system is helping fuel a relief center’s operations.

In the storm’s wake, solar companies have been donating equipment across New York and other stricken areas to function as emergency power systems now and backups in the longer term. It is important, executives say, to create smaller, more decentralized ways of generating and storing electricity to help ease strain on the grid in times of high demand or failure.

“The grid won’t evolve into something more distributed and fault-tolerant overnight — it’s still dependent upon a centralized system,” said Ben Tarbell, vice president for products at SolarCity, a leading installer that has donated generators after Hurricanes Katrina and Sandy and is developing a battery backup system for its customers. “But the components are starting to come together.”

Generally, home systems like Mr. Antonio’s are engineered to feed electricity from the roof array through an inverter and into the home’s electrical panel, sending the excess to the broader electric grid. But during a failure, the inverter automatically shuts down the system to guarantee that no electricity is flowing into equipment that workers will be trying to fix. The shutdown also ensures that the system’s current will sync with the grid when power is restored and guards against damaging the lines.

Certain systems allow solar panels to run a household directly during prolonged power failures, generally combined with battery storage to keep the power functioning around the clock. Those require installing a separate electrical panel and a more complicated inverter that would switch the flow of electricity entirely over to the house, perhaps to a few critical circuits to run, say, the refrigerator, some lights, television and minimal heat.

“You size the battery system to go with that, and then the system will work just on those dedicated circuits,” said Tony Clifford, chief executive of Standard Solar, an installer based in Maryland.

The cost of adding battery storage to an existing system can range from $500 to $30,000, depending on how large the solar array is and how much the customer wants to be able to run.

Although demand for battery backup is not yet widespread, interest tends to go up after storms, said David Panico, senior vice president of the industrial power group at SunWize, a solar supplier that provided a low-cost mobile system to the Rockaway Beach Surf Club, a hub of that area’s relief effort.

But a drawback is that residents have to figure out where to put the batteries — a particular quandary for those with homes vulnerable to flooding.

So some are looking at electric vehicles as potential backup energy sources instead. In some cases, a car could fuel a house for days on a single charge.

Comments are closed.