Making the move away from using fossil fuels for heating is a necessary part of creating a sustainable future, but it’s often a difficult ask for many people when turning up a thermostat on a gas or electric heater provides instant, trouble-free warmth.
If people are to be convinced to switch to more renewable sources, it makes sense that there need to be easy-to-use systems available to encourage them to do so. A group of Swiss researchers claim to have come up with a process that stores heat captured during summer for easy, flick-of-a-switch use in winter, with the added benefit that the captured energy can be physically transported anywhere it may be needed.
Created by researchers working at EMPA (Eidgenössische Materialprüfungs-und ForschungsAnstalt or, in English, the Swiss Federal Laboratories for Materials Testing and Research), the new system uses concentrated sodium hydroxide (NaOH) as the thermal storage medium, and a collection of largely off-the-shelf components to capture, convert, and release heat energy on demand.
To achieve this, the researchers rely on the fact that when water is poured onto dry sodium hydroxide an exothermic reaction ensues, where the chemical energy contained in the NaOH is released as heat. As NaOH is also extremely hygroscopic (that is, having a great attraction for dragging in and holding water molecules from the surrounding environment), more heat is produced from water condensing from vapor in the air and the sodium hydroxide solution is heated even further. In this way, large amounts of heat may be liberated from NaOH simply by the addition of water.