RICHMOND, Calif. — Continuing its efforts to bring energy storage to both utilities and facilities with large refrigeration and air conditioning needs, Axiom Exergy has been granted a patent for direct expansion thermal energy storage. The company said this strengthens its position to extend its “ice battery” technology to HVAC applications that use variable refrigerant flow (VRF) systems, which research shows represents about 24 percent of the global commercial air conditioning market.

The patent comes on the heels of $2.5 million in funding announced this summer from investors to help fulfill over $5 million of contracts for key demonstration projects in California and a large, multi-site rollout with Con Edison in New York. The company has also been accepted into StartX, an accelerator program affiliated with Stanford University and the Stanford-StartX fund.

Using the Axiom Exergy thermal energy storage technology, businesses with large refrigeration-based energy loads can reduce their peak electricity demand by up to 40 percent, said the company. Its Refrigeration Battery can shift six hours of a building’s refrigeration-based electricity loads, leveraging the existing refrigeration system’s excess capacity to “store cooling” at night by freezing tanks of salt water. During afternoon peak hours, the Refrigeration Battery uses the frozen tanks to supply refrigeration services to the building, eliminating the need to run energy-intensive compressors and condensers.

The Refrigeration Battery is a modular retrofit that operates in parallel with existing refrigeration systems to shift daytime energy loads to less expensive off-peak hours. It can also provide backup cooling to reduce uninsured food spoilage during power outages, an expensive problem for supermarket owners. Installation of the Refrigeration Battery does not require physical or programming modifications of existing equipment.

“Existing thermal energy storage technologies were designed for use with cooling systems that use air or water as the heat transfer medium,” said Anthony Diamond, chief technology officer and co-founder of Axiom Exergy. “We believe that we now hold the seminal patent for the beneficial application of thermal energy storage in an entire family of cooling systems: direct expansion. Securing this patent is particularly important for us because it lays the groundwork to considerably expand the application of our technology into new markets, and it increases the impact our technology will have on accelerating the global transition to renewable energy.”

Beyond supermarkets and cold storage facilities, Axiom said its technology can also be applied to a wide variety of other cooling applications found in food manufacturing processing and packaging facilities, along with small-format retail like convenience stores. In addition, the patent protection extends to VRF systems. VRF is the predominant form of commercial air conditioning in countries like Japan and Germany, and it is also said to be the fastest growing segment of the commercial HVAC market in the U.S.

Axiom said it is in discussions with several major OEMs with investments in the global air conditioning market who stand to benefit from incorporating Axiom’s intellectual property.

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Publication date: 10/24/2016

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