Salt and water vapor are used in the thermal battery, explains Olaf Adan, professor of applied physics at Eindhoven University of Technology. “If you put them together, the heat is released. But you can also separate them from each other.”

No heat loss

By adding heat, the water evaporates and you heat the salt until it dries. “As long as the water does not reach this dry salt powder, heat is still stored in it,” he tells EditieNL. “Unlike other types of heat storage, nothing is lost.”

You can charge the battery in places with a lot of residual heat, such as power stations. The heat is stored and can later be used elsewhere, for example in homes or offices. Time and place do not matter. “And this is special, because there is no storage technology other than lossy,” Adan explains. “Normally, heat is lost during long-distance transportation.”

potassium carbonate

However, the process is not possible with every type of salt. “We do this with potassium carbonate. It’s non-toxic, non-flammable, and abundant. You have to extract the potassium chloride and bubble the carbon dioxide through it. We get it from Germany, because that’s where one of the major producers of potassium carbonate is.”

Advantages

According to Professor Adan, the new thermal battery has three main advantages. “It’s greener than other solutions, it’s a lot cheaper – salt is available – and it runs faster. We don’t have to pipe in and the heat we’re using is already there, because it’s residual heat.”

The first pilot will soon begin in Sittard. “In order to be able to do this at scale, we still have to make a breakthrough on two fronts: To stabilize the salt, we developed a device three years ago. We are now scaling up this process. In addition, it is difficult to get funding. Widely. “

mobile salt

Han Slotwig, a professor of electrical supply, sees a challenge, too. He asks, “If you want to get the heat from somewhere else, say from a factory, you have to truck grains of salt. Isn’t that a lot?”

About 20 cubic meters of salt are needed to power fifty homes for one to two weeks. “So you need a lot of salt for 3.5 million families.”

Slootweg is still excited. “The advantage of this battery is its ability to store heat. The energy generated by the solar panels during the day when you are not at home can be converted into heat. This energy is stored and you can use it to heat your home in the evening.”