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Renewable energy has come a long way this year, even as certain challenges seem to block its progress. One of these major hurdles is developing new ways to store energy, since not all storage methods work in the same places. Here’s a look at new storage solutions, such as the frozen air strategy.

Vermont’s Renewable Power System

Due to low capacity power transmission lines for the scattered and relatively small population of Vermont, power lines usually become too congested for the grid to provide renewable energy to many homes. Yet the state has a goal to draw 90 percent of its electricity from renewables by 2050.

The state could benefit from the concept of storing energy using frozen air. The idea was proposed by UK-based Highview Power. The system generates electricity from solar or wind, then freezes air into liquid form and placed in insulated storage tanks. The liquid can be stored for several weeks and used when needed. Once the frozen air is needed, it can be warmed and converted back into gas, which is capable of moving a turbine in an electric generator.

Salvatore Minopoli, VP of Highview Power’s U.S. affiliate, says that several areas across America have a similar issue, in which power lines are unavailable or impractical for transmitting renewable energy. He says the longer the period energy needs to be stored, the more frozen air is an appropriate solution. It’s more efficient than turning to large storage batteries.

Future Energy Storage Concepts

Utilities have used alternatives for energy storage for several years that may be overlooked by other entities. Using non-battery pumped storage, for example, to move water uphill can be useful as long as electricity isn’t too expensive. In those cases, water can flow downhill into a generator.

Power plants have also pumped air into abandoned natural gas fields as a way to spin a turbine. But hills aren’t necessary for a liquid air energy storage system (LAES) to generate electric power. This system can be installed on any 2-acre site and may be best suited for former coal plants. These sites are ideal because they often still have transmission lines that connect with the grid.

Highview Power has issued a press release recommending to install its first U.S. storage facility in Vermont. The company says this facility will be able to capture and store 400 megawatt-hours of electric power, serving up to 50,000 homes for up to eight hours.