Solar power has potential but a crippling weakness that has meant despite trillions of dollars in subsidies and continuing mandates, it has not made a dent in use of conventional energy; it is not on demand and batteries are expensive and going to do more harm to the future than natural gas.

The solar energy system MOST – Molecular Solar Thermal Energy Storage Systems - is starting small but the concept of a specially designed molecule that changes shape when it comes into contact with sunlight scaled to operational sizes might mean real solar farms in remote places that provide electricity as well as conventional energy.

Recent tests show MOST can capture solar energy, store it for up to eighteen years and release it when needed but now they have connected it to a thermoelectric generator, which could lead to self-charging electronics using stored solar energy on demand.

Credit: Chalmers University

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

Scholars at Shanghai Jiao Tong University in China received the specially designed molecule, loaded with solar energy, from Sweden and the energy was released and converted into electricity using a generator. Essentially, Swedish sunshine was sent to the other side of the world and converted into electricity in China.

Molecular Solar Thermal Energy Storage Systems, Most, is a closed energy system based on a specially designed molecule of carbon, hydrogen and nitrogen, which when hit by sunlight changes shape into an energy-rich isomer – a molecule made up of the same atoms but arranged together in a different way. The isomer can then be stored in liquid form for later use when needed, such as at night or in winter.

The researchers have refined the system to the point that it is now possible to store the energy for up to 18 years. A specially designed catalyst releases the saved energy as heat while returning the molecule to its original shape, so it can then be reused in the heating system. Now, in combination with a micrometer-thin thermoelectric generator, the energy system can also generate electricity to order.

It's proof of concept but if it can scale then it may provide a path to viable solar energy, without poor people having to pay extra utility fees because they can't afford solar panels.