Researchers developed a fluid that absorbs solar energy and stores it for up to 18 years.

Source: Chalmers University 

We all know that solar energy will be the future — once the planet’s fossil fuel reserves have been depleted.

Solar energy, on the other hand, faces two problems today: the first is that it is only usable during the day, and the second is that it must be stored for long-term use.

However, a group of Swedish scientists may have found a solution to the second problem. They’ve created “solar thermal fuel,” a unique form of fuel that can store the sun’s energy for up to 18 years. Researchers from Chalmers University of Technology in Sweden have been working on it for over a year.

MOST, which stands for Molecular Solar Thermal Energy Storage System, is the system that assists in the capture of solar energy. It operates in a circular fashion, with the fuel being cycled into clear tubes by a pump.

The bonds between the atoms are rearranged when they come into contact with sunlight, resulting in an energy-rich isomer. The sun’s energy is then trapped in these tight chemical bonds. Surprisingly, even after the liquid cools down to room temperature, this energy stays strong.

The liquid is passed through a catalyst produced by the research team, which causes a reaction that warms the liquid by 63 degrees Celsius. This restarts the process, restoring the molecule to its original state and releasing the energy as heat.

This heat can be used to warm water in a building’s water heater, dishwasher, and other applications. It can also be used in industrial applications, including sterilization, distillation, and low-temperature cooking heat, among other things.

The same fluid can be poured back into MOST and reused, collecting and storing solar energy once more. The same fluid has been reused over 125 times without any disruption to its molecular structure.

Source: Chalmers University

According to the research team’s head, Kasper Moth-Poulsen, Professor at the Department of Chemistry and Chemical Engineering, the liquid will store up to 250 watt-hours of energy per kilogram at its full capacity, which is nearly twice as much as Tesla Powerwall batteries.

For the time being, Chalmers researchers are designing prototypes of the technology for large-scale operations. They’ve got a 4.3 million Euro grant from the European Union, which will last three years.

“With this funding, the development we can now do in the MOST project may lead to new solar-driven and emissions-free solutions for heating in residential and industrial applications,” said Moth-Poulsen in a statement. This project is about to enter a critical and inspiring phase.”