Swedish physicist Kasper Mott-Poulsen calls his invention "solar thermal fuel". It is a liquid that stores energy like a battery, but uses direct sunlight instead of electricity. And when released, a chemical reaction takes place with the release of heat, and the process can be regulated by "burning" portions of fuel for useful work. The substance itself is safely stored in the intervals in a regular bottle.
On the roof of the Chalmers University of Technology in Gothenburg, the scientist mounted an experimental setup. The substance norbornadiene flows through transparent pipes, which, when irradiated by the ultraviolet light of the Sun, transforms into its energetically excited version - the quadricyclan. Solar counting rebuilds the bonds between hydrogen, nitrogen and carbon atoms, which requires a large expenditure of energy absorbed in the process. The cooled quadricyclan is inert until it reacts with a cobalt-based catalyst, at which point the process reverses. The liquid is converted to norbornadiene, and the excess energy is given off as heat.
The amount of heat generated is very large, the liquid heats up almost instantly to 63 ° Celsius. At the same time, the consumption of the catalyst is symbolic, and, using competent engineering solutions, it is not difficult to build a thermal circuit with its help for heating the building. According to calculations, solar thermal fuel can store up to 250 Wh per 1 kg of mass - twice as much as Tesla Powerwall's “home” batteries. And the waste liquid can be easily recharged or stored without any isolation and without losing its properties.
The last quality became a breakthrough. Norbornadiene-based fuel was developed back in the 1970s, but it was unstable, the molecules of the substance fell apart after a couple of recharge cycles. And Kasper Mott-Poulsen managed to achieve 125 recharge cycles for certain types of mixtures without signs of degradation, and this is just the beginning. He does not make a special secret of his developments, if only because every month more and more scientists around the world are joining the work on a new version of solar thermal fuel and new details and nuances are constantly being discovered.
Kasper Mott-Poulsen constantly receives tempting offers from commercial structures, but is in no hurry to accept them. For practical use, his brainchild is not yet ready. For example, recharging is possible only from ultraviolet radiation, at the longest wavelengths of light, which is only 5% of solar energy. And heating by 63 ° is not enough, you need 90-100, so that the battery with fuel is self-sufficient and can be used directly, in the same kettle. But he has no doubts that this technology will revolutionize the global energy industry in the next decade.