Without using electricity from the public grid, more people are able to keep the lights on when the sun doesn’t shine.
The next step up in the growth of green energy is approaching rapidly as the use of batteries to store energy from solar panels for use at night or on stormy days – or even during a power outage – is becoming more common.
Bill Laberge, owner of Grassroots Solar, has recently begun installing Sonnen batteries for customers who already own solar panels and to his customers who are having panels installed. "Every single one of my customers asks me about batteries," Laberge said. "So we’re just now introducing these batteries in Vermont, and my customers are responding really well."
The Sonnen battery packs are making it possible for some solar users to go off the grid completely during some parts of the year. Others use them strictly as back-up for use in a power outage.
The lithium-iron phosphate batteries come in modules, each of which can power an average home for about two kilowatt hours when fully charged, Laberge noted. They can be bundled for up to 16 kilowatt hours of power storage, meaning that the battery pack could run all night long, or all day during an outage.
The accompanying integrated energy management system controlling the system will divert the solar energy being generated into the recharging the batteries when not being used in the house, if everyone is at work or school, for example, Laberge said.
The main disadvantage of solar panels has been that when the sun is out, many people are not home to use the power. But when they come home for the evening, the sun is already setting. Batteries enable the system to make the solar power available when it’s most needed, in the evening when the family is home using the lights, TVs and computers.
As a result, in a year’s time a residence could have zero net power usage from the grid, depending on their usage and the size of their solar installation and storage system. "It gets rid of your electric bill and when the power goes out, your lights are still on," Laberge said. "So really, we’re moving from a solar installation company to an energy management company."
In fact, many will have excess credits for generating power into the grid. And state law allows the user to choose to share those credits with friends or family to reduce their power costs.
George and T.J. Mora of Londonderry recently purchased an 11.7 kilowatt solar system and batteries that will store up to 14 kilowatt hours of electricity. They are sharing their credits with a nearby neighbor, George Mora noted. She said the batteries take about three to four hours to recharge on a sunny day.
"We’d been talking about going solar for about 10 years," Mora said. "We wanted to be as self sufficient as we could get. We thought we would just feel more secure if we had some autonomy."
She said there is no noticeable difference in the delivery of electricity to the house, she said, other than the fact that they’re saving about $120 per month. "This has multiple benefits," Mora noted. "We’re reducing our expenses and we’re not dumping fossil fuel exhaust into the atmosphere, and we’re not we’re no longer supporting the fossil fuel industry."
They system also allows the Moras to go online and check on exactly how much power they are using and how much power is being generated and stored.
The race to develop batteries capable of safely recharging, storing and expending significant amounts of electricity coming from renewable sources has been the focus of a wide variety of technologies, companies and research.
Some have said that when the battery technology becomes widely available, the use of renewable power will take a giant step forward in becoming more practical, allow much more widespread usage and dramatically reduce the use of climate changing fossil fuels.
Incremental steps forward in developing chemical battery technology have come to the point where the use of batteries has become available for homes and even some commercial applications. "We’re seeing more and more growth, and we expect to see the number of larger projects explode when Sonnen introduces commercial size storage batteries," Laberge said.
"Ideally everybody should be generating their own electricity," George Mora said.

Source: http://www.manchesterjournal.com/stories/solar-power-at-night-now-its-possible,489673