How a British Startup is Reinventing Cooling Systems

The O-Hx Energy Vault is a patented high-density thermal battery designed to store and rapidly release cooling power for industrial-scale applications.

To find out more listen to the full podcast episode here. 

When Bob Long began scouring the globe in 2017 for a thermal energy storage system, he was certain such a product must already exist. After all, the world’s accelerating shift to wind and solar power was creating a need for reliable storage to bridge the gaps between supply and demand. But his search turned up nothing. So Long, an engineer with decades of experience in applied thermodynamics, decided to create one himself.

The result is O-Hx  and its flagship technology, the Energy Vault, a patented thermal battery capable of storing and rapidly releasing cooling power on an industrial scale. The principle is explained by Long as a more technical version of creating trillions of ultra-thin ice particles with a high surface-area-to-volume ratio. “It’s like the difference between a sugar cube and granulated sugar,” explains Long, who holds the role of Executive Chairman at the firm. “One melts slowly, the other almost instantly.” You need quick access to the cooling system and therefore keeping it refined allows for quick and reliable use. 

Proving the concept took years of R&D, early investment from the founders, and a relentless focus on solving the engineering bottleneck: how to stop those microscopic ice particles from clumping together. By 2021, Long and his small founding team had a working prototype, and the confidence to raise seed capital. A full-scale production model followed, installed in an industrial setting and tested for two years without failure. Long jokes that, “we tried to break it for two years unsuccessfully!”. 

Now, O-Hx is moving from proof-of-concept to gaining market traction. The technology is live and being utilised at three sites, including a vertical farming facility in Dundee and a pharmaceutical plant in Cramlington in Northumberland, as well as in discussion with the National Health Service. At £250,000 per unit, sales processes can be long.“It’s not something you buy over tea and cakes,” as Long puts it, but early demand is promising. 

By integrating AI-driven software, O-Hx can help customers charge when energy prices dip, sometimes into negative territory, and discharge during peak costs, optimising both economics and emissions. And because chilled water is the delivery medium, the system sidesteps the safety and insurance issues that come with refrigerants such as ammonia, CO₂ and propane.

With global chilled water markets worth an estimated $600 billion a year, Long's ambitions are international. “We’re a small company with an absolutely Goliath product,” he says. “Within four years, we expect to be manufacturing on every continent.” That expansion will rely on partnerships, licensing O-Hx’s growth template to local operators rather than scaling alone.

For investors, the proposition sits in the sweet spot between infrastructure necessity and defensible IP. O-Hx holds an exclusive patent and with demand for resilient, low-carbon cooling set to soar, especially as new sectors emerge, for example,  liquid-cooled data centres, Long believes the real challenge is not finding buyers, but keeping up with them.

“We know competition will come,” he says. “Our job now is to get the technology out there before it does.”

To find out more listen to the full episode here.