One the biggest obstacles to the growth of renewables is how to store energy from solar and wind sources when the sun isn’t shining or the wind isn’t blowing. A startup based in Corvallis, Oregon believes it may have a solution.

Applied Exergy has developed a new technology they call Thermal Approach to Grid Energy Storage, or TAGES (pronounced “tags”) for short. By utilizing a new kind of microchannel heat exchanger technology developed at Oregon State University, energy generated from renewable sources is used to cool water down into an icy slurry, in effect “storing” the energy in the ice. When the stored power is needed, waste heat from almost any source can be used to melt the mixture back into liquid form so it can flow through the turbine blades of a generator, producing electricity that can then be sent out to the grid. The melted water is then returned into the tank to be re-frozen and used again.

“It’s essentially an air-conditioning unit combined with a steam power plant,” said Chief engineer Kevin Harada. “The efficiency of the plant is based on temperature differences.”

While there has been plenty of research done on using ice to store energy, Applied Exergy says that the slurry works better than a solid chunk of ice because it melts down much faster.

“The advantage of the ice slurry is it’s very tiny little ice cubes, so water will flow through it,” said Harada.

Seems Mr. Harada and company aren’t alone in believing in the strength of their technology, as the company has secured a $150,000 grant from the Oregon Built Environment & Sustainable Technologies Center to build a demo model and over $500,000 in grants and private investments. Local utility company Portland General Electric is evaluating the technology for future use, and Applied Exergy is currently seeking an additional $15 million in financing for its manufacturing and infrastructure plans.

According to the company, the TAGES system should cost less than $1,000 per kilowatt-hour of generating capacity to install, built to be moveable and stackable, and easily integrate into current HVAC systems. Could the future of energy storage take the form of that age-old childhood favorite, the Slushie?

[via Corvallis Gazette-Times]

Image Credit: K E L S E Y . R