When people think of energy storage, they generally think of big batteries that soak up electricity to save it for when it's needed most.

But batteries can be expensive, and they degrade over time. That has the competition looking for more efficient and low-cost solutions, such as storing electricity in the form of ice.

Ice storage — or thermal storage — uses the power grid's low-cost electricity during the evening hours to freeze water. That essentially stores the lower-cost energy in the form of ice, which is thawed during the day and deployed to cool large buildings.

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The storage device, known as an Ice Bank, helps to offset the steeper charges buildings accrue when using electricity during the day, when prices are the highest, to run standard chillers.

Ice storage is not really so novel, but it's a smarter way of using electricity. The technology is being deployed in schools and commercial buildings, with the latest example seen at tech giant Google's offices in New York City.

Mark MacCracken, the CEO of energy storage firm Calmac, which makes the Ice Bank, says his ice-based system takes a different approach to his big-battery counterparts, such as Tesla Motors CEO Elon Musk.

Musk's new grid-based batteries are priced at $300-$400 per kilowatt hour, while the Ice Bank is $100 per kilowatt hour, MacCracken says.

"Our system is the low-hanging fruit," MacCracken said, meaning it provides power savings that can be the most easily achieved before deploying more expensive hardware such as batteries. He says the grid is going through a transition where more storage will be needed to offset the intermittency of wind and solar.

A study issued in April listed Calmac as one of the leaders in thermal energy storage technologies. The report, Global Thermal Energy Storage Market 2015-2019, shows the thermal storage market is expected to grow $1.3 billion by 2019.

Like the Ice Bank, batteries can soak up electricity to offset power demand, but they do it at nearly nine times the cost, according to a recent Calmac study. It says six batteries are required to equal the same storage capacity as one Ice Bank.

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MacCracken has been meeting with his would-be competitors to discuss a collaboration that would offer the cost savings of his device to run air conditioning systems, and batteries would run lighting and other systems.

The result would be less money spent by the customer to employ systems that incorporate both banks and batteries, he said. McCracken says "their costs would drop by a factor of three" if they combined batteries with ice storage. "I think we are making headway."

Energy storage is getting a lot of attention by states looking to switch to increasing amounts of wind and solar. The market in California has an energy storage mandate that requires all major utilities in the state to deploy a certain percentage of energy storage to help meet the state's renewable energy goals.

Other incentives are being contemplated for the technology, including a recently introduced bill by Sen. Martin Heinrich, D-N.M., to create a nationwide energy storage target similar to California's 1.3 gigawatt target.

Because most renewable energy, such as solar and wind, are intermittent power generators, they require a back-up source of electricity in the form of storage to make up for when the wind stops blowing and the sun stops shining. MacCracken says the Ice Bank is already being deployed in California.

New York state also has an advanced energy program where the devices are finding a home. The latest installations are running Google offices in Manhattan, Rockefeller Center and a number of other large buildings in New York City.

The McConnell Air Force Base in Kansas, Hewlett-Packard Foundation headquarters, the Sarasota County School District, University of Arizona and new sites in Texas are deploying the bank, to name a few. Calmac says nearly 4,000 sites around the world are deploying the technology.

The company is also working with the solar energy industry on a group of projects that incorporate thermal storage with solar energy arrays.

The technology can even be used in newer "net-zero" buildings that are designed to produce as much energy as they consume, and can reduce electricity use from the grid to a bare minimum.

MacCracken says new construction standards for buildings also incentivize the use of thermal storage.