Hold onto your hat/life partner/gonads: Scientists in Germany have created small, zeolite pellets that can store up to four times more heat than water, loss-free for “lengthy periods of time.” In theory, you can store heat in these pellets, and then extract exactly the same amount of heat after an indeterminate amount of time.

Zeolites (literally “boil stones”) aren’t exactly new: The term was coined in 1756 by Axel Cronstedt, a Swedish mineralogist who noted that some minerals, upon being heated, release large amounts of steam from water that had been previously adsorbed. For the last 250 years, scientists have tried to shoehorn this process in a heat storage system — and now, the Fraunhofer Institute, working with industrial partners, has worked out how to do it.

I will try to explain how this works, but the science is fairly complicated: When Fraunhofer’s zeolite comes into contact with water, a chemical reaction adsorbs the water and emits heat. When heat is applied to the zeolite, the process is reversed and the water is released. Because the heat is locked up in the chemical structure of the zeolite, the material never actually feels warm — which is why this is a “loss-free” storage method.

These two processes can be kept separate — so first you charge the balls up with heat, and then later you can just add water (!) to release the heat. This reaction occurs all along the surface of the zeolite — and because zeolites are porous, a single gram of the material has a surface area of 1000 square meters (10,700sqft). It is for this reason that Fraunhofer’s zeolite can store up to four times more heat than water.

While the hydration/dehydration process is well understood, the main technical challenge was building an actual heat storage system. “First we developed the process engineering, then we looked around to see how we could physically implement the thermal storage principle — i.e. how a storage device has to be constructed, and at which locations heat exchangers, pumps and valves are needed,” says Mike Blicker, the group manager. As you can see in the picture on the right, the setup is fairly complicated. The team has now successfully built a transportable 750-liter storage tank, which is currently being wheeled around Germany to test the storage system in real-world situations.

Moving forward, this could be huge news for almost every technological and industrial sphere. Currently, there are very few options for storing heat other than water, which can’t store much heat for a given volume, and it loses heat relatively rapidly. Power plants, biogas plants, steel mills, factories — these all produce vast amounts of heat that could (and should) be reused. They wouldn’t even have to be used on-site, either: charged-up zeolite balls could be distributed to nearby homes and offices. In the future, Blicker suggests that we could eventually replace house water tanks with zeolite systems, too. “It would be ideal if we were able to devise a modular system that would allow us to construct each storage device to suit the individual requirement,” says Blicker.

Personally, I’m hoping for a module small enough to put inside each of my seven computers. I wonder if that’ll be enough to heat my shower in the morning…

Read more at Fraunhofer, or check out Microsoft’s solution to waste heat: Data furnaces