Researchers convert solar energy to electricity on demand

Researchers at Chalmers University of Technology in Sweden have developed a system to capture and store solar energy for up to 18 years and then release it when needed to produce usable electricity. Eventually, the research could lead to self-charging electronics using stored solar energy on demand.

Based on Chalmers’ Molecular Solar Thermal Energy Storage system, or MOST, the technology relies on the principle of a special kind of molecule that changes shape to become an energy-rich isomer when exposed to sunlight, which can then be stored in a liquid form for later use.

A catalyst causes the molecule to return to its original shape, releasing its energy as heat in the process — that heat can be used by an attached thermal generator to produce electricity. The MOST system had previously used flammable chemicals but recent advances have replaced this with less volatile substances.

“This is a radically new way of generating electricity from solar energy. It means that we can use solar energy to produce electricity regardless of weather, time of day, season or geographical location. It is a closed system that can operate without causing carbon dioxide emissions,” said research leader Kasper Moth-Poulsen, Professor at the Department of Chemistry and Chemical Engineering at Chalmers.

The researchers suggest that the system can be used to capture the sun’s power and then release it at night or during the darker periods of winter to generate power on demand. At the moment the liquid can store energy for up to 18 years and although current levels of power production are relatively low, the scientists are working to produce a higher amount.

“Together with the various research groups included in the project, we are now working to streamline the system. The amount of electricity or heat it can extract needs to be increased. Even if the energy system is based on simple basic materials, it needs to be adapted to be sufficiently cost-effective to produce, and thus possible to launch more broadly,” said Moth-Poulsen.

The study outlining the MOST system has been published in Cell Reports Physical Science.

Image credit: Chalmers University of Technology | Johan Bodell