Cryogenic energy storage for data centers is a great idea, but since I looked at it four years ago, nothing much seems to have happened. But last month, the idea came to life again.

Liquid gas is a way to store energy. The gas can be kept in insulated cylinders till required. Then when it is released, as it expands and evaporates, it can drive turbines and generate mechanical or electrical energy.

dearman engine lead
The Dearman engine – Dearman

Expansion drive

The principle is sound, and 40 years ago British self-taught engineer Peter Dearman designed an engine which can drive a car. The drawback is Boyle’s law. The expanding gas becomes colder and a lot of the energy is lost this way.

So Dearman Ltd has been finding applications where energy and cooling are both required. It makes motors which drive refrigerated trucks for supermarkets… and simultaneously cool the trucks. Basically, these systems can replace diesel engines in settings which also need refrigeration.

Dearman has been looking for other sectors which need both power and cooling and has now spotted data centers. They have diesel engines for backup power, and they have heat that needs to be removed.

So Dearman has entered into a partnership with a Malaysian startup, Green Data Center LLP, and will be doing research into how its engine can be applied there.

The company says that it is too early to jump to any conclusions, but I’m already seeing some issues that will have to be addressed.

Questions raised

Firstly, data centers needs for power and cooling aren’t necessarily in line. Cooling is needed all the time the servers are running, but in most cases, except on hot days, free cooling is enough, so additional cooling is not required.

Meanwhile the diesel generators at a data center are almost never run. They are for backup.

Finally, the Malaysian partner Green Data Center is a startup whose products seem to be in an early stage. In fact, we’ve not heard of it before. But one thing that is very definite on  GDC’s site, is a statement that the company’s Eco2 sustem uses immersion liquid cooling.

Dearman has been looking for other sectors which need both power and cooling and has now spotted data centers.

The main benefit of liquid cooling of this nature is that it removes the need for other kinds of cooling. Indeed, the cooling fluid ends up containing heat at a useful temperature, which can potentially be sold. So cooling it would actually be a waste.

So on the face of it, the Dearman engine could end up being run rarely, and its cooling could be superfluous with this particular partner.  But the Dearman people are smart, and these points are pretty obvious, so I know they are well aware of them.

Dearman has assured me the project has plenty of angles to explore, and the whole point is to see how to use these technologies for mutual benefit. So I’ll be looking forward to hearing more from it, and I also want to know more about the mysterious GDC.

A version of this article appeared in Green Data Center News