Owner system

Liquid system stores solar energy for years and releases it on demand

In 2017, we heard about an interesting energy system from researchers at Chalmers University of Technology in Sweden, designed to store solar energy in liquid form. By connecting it to an ultra-thin thermoelectric generator, the team has now demonstrated that it can produce electricity, a development which they say lays the foundation for self-charging electronics that use solar power. on demand.

Called the MOlecular Solar Thermal (MOST) system, the technology has been in the works for more than a decade and focuses on a specially designed molecule of carbon, hydrogen and nitrogen. When it comes in contact with sunlight, the atoms of the molecule are rearranged to change its shape and turn it into an energy-rich isomer, which can be stored in liquid form.

The energy captured by the MOST system can be stored in this liquid state for up to 18 years, before a specially designed catalyst returns the molecule to its original shape and releases the energy as heat. The Chalmers team has now collaborated with scientists from Shanghai Jiao Tong University in China, who have used a compact thermoelectric generator to turn this heat into electricity.

“The generator is an ultra-thin chip that could be embedded in electronic devices such as headphones, smart watches and phones,” said researcher Zhihang Wang from Chalmers University of Technology. “So far we have only generated small amounts of electricity, but the new results show that the concept really works. It looks very promising,”

The MOlecular Solar Thermal (MOST) system can store solar energy in liquid form

Chalmers University of Technology/Daniel Spacek/neuroncollective.com

The proof-of-concept current output is reported to be up to 0.1 nW (output power per unit volume up to 1.3 W m−3), which could be quite low, but scientists see a great potential in their MOST system, which could solve the intermittent problem. nature of solar energy by storing it for months or years at a time and allowing it to be harnessed on demand.

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

Having now shown that the system can be used to generate electricity, the team is focused on improving its performance, while working on an affordable commercial solution for charging gadgets and heating homes.

“With the various research groups included in the project, we are now working to streamline the system,” said Kasper Moth-Poulsen. “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 profitable enough to produce, and therefore possible to run more widely.”

The research was published in the journal Cellular Reports Physical Sciences.

Source: Chalmers University of Technology