How long could a big battery power your home?

The Sacramento Municipal Utility District is funding a $5.9 million energy storage demonstration project to study how batteries could help during peak demand.

Apparently, there are more new homes constructed with solar power in Sacramento than anywhere else in the United States. The district is also the site for a pretty exciting test project in the realm of energy storage.

Over the next 18 months, the Sacramento Municipal Utility District (SMUD) will support a $5.9 million demonstration that will evaluate how large lithium-ion batteries could help reduce the load on electric grid during periods of peak demand.

Under the test program, 15 homes in the Anatolia subdivision of the SolarSmart Homes community in Rancho Cordova, Calif., will install the batteries in their garages; another 27 will share three located in neighborhood common ares.

The homes will be switched over to battery power during the afternoon hours, when the region is typically the hottest and electricity demand across the district traditionally rises. The batteries will be charged overnight, when power costs are lower.

"The aim of the program is to learn whether or not batteries can ease load demand and provide more electricity when renewable energy sources such as solar and wind power aren't sufficient," said Paul Lau, assistant general manager for Power Supply & Grid Operations, SMUD. "The project will also help us better understand how battery storage and solar mesh with time-of-use rates, where customers pay more for electricity during peak hours and less during low-demand times."

Of course the homes in the project were designed to be more efficient than average, with a footprint that is approximately 40 percent smaller. But the demonstration will provide valuable data about how intermittent energy sources such as solar photovoltaic or wind turbines might benefit from energy storage.

According to SMUD, the batteries being used in the individual test homes are about the size of a miniature refrigerator and could power a home for between two and three hours, depending on the appliance load. The community-shared batteries are bigger, and have approximately three times the capacity of the in-home units.

Homeowners will have panels that help them see how much energy they are generating, and using.  

New analysis by Pike Research shows that the energy storage industry is recharging  as more renewable energy installations include the technology as a component.

Energy storage projects rose 8 percent to 649 in the first half of 2012, compared with a year ago. The number of projects that actually became operational during the first six months of this year was 514. 

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