This problem has plagued solar energy for a long time, but this can change as the ultra-lightweight way of saving solar energy is offered.
Swedish researchers have created a special fluid called "solar heat". It is said that this fuel can store accumulated solar energy for more than a decade.
"Solar energy is like a rechargeable battery, but instead of electricity, you set the sun's rays and heats. And everything depends on your needs," said Jeffrey Grossman, an MIT engineer with these materials, NBC News.
This fluid is in fact a special fluid molecule, to which researchers from Chalmers University of Technology (Sweden) have worked for more than a year.
This molecule consists of coal, hydrogen and nitrogen, and when exposed to sunlight, it begins to occur abnormally: the connections between the atoms are restored and the molecule becomes an isomer.
Just like looting in the trap, solar energy is caught in isomers that have strong chemical connections. And the energy is stuck even when the molecule cools down to room temperature.
When it comes to energy – say, at night or in winter – the catalyst is exposed to the catalyst, which returns the molecule to its original state and thus extinguishes energy.
"The energy of these isomers can be stored for up to 18 years," says one of the group members, a nanoscale researcher from Chalmers University, Kasper Moth-Poulsen. "When we decided to release the locked energy, we got a heat increase that was higher than we dare to expect."
Such a prototype of the energy system is installed at the university building ceiling, and when the new fluid was used and very optimistic results were obtained, researchers attracted many investors.
Renewable and non-polluting, the new energy device consists of a concave reflector with a centered tube that catches the sun's rays and acts as a kind of satellite dish.
The MEST system operates on a closed circuit basis. The permeable liquid through the transparent tubes is heated by the sun and the so-called norbornadiene molecules in the liquid are converted to isomeric quadricyclones that block the heat. This liquid is then stored at room temperature to minimize energy loss.
When energy is needed, the liquid passes through a special catalyst which returns the molecules back to its original shape, and this fluid rises to 63 degrees Celsius. Therefore, it is likely that this heat can be used in different building heating systems.
The scientists repeatedly used the fluid 125 times – collected the heat of the sun, protected it and relaxed it – and did not notice that it would lead to more damage to these molecules.
"We have recently made many important discoveries, and today we have an energy system that works all year long and does not pollute the environment," says Moth-Poulsen.
According to NBC, researchers have made some discoveries that have made it possible for its special fluid to store 250 watts per kilo, which is twice as high as the Tesla Powerwall battery system can offer.
But there are still plenty of opportunities for new achievements. Scientists believe that with the right manipulation tools they can get even more heat from such a system – at least 110 degrees Celsius.
"There is still a lot to do. We have only managed to get this system working. Now we need to make sure everything is optimally designed," says Moth-Poulsen.
If everything goes as planned, Moth-Poulsen believes that this technology can be started commercially for commercial purposes over the next ten years.
The latest research results were published in the journal Energy & Environmental Science.