"We started with materials that have higher difference in energy between the liquid and solid states. The reason why this is so important is because we can store a lot of energy in very short volumes," says Merete Tangstad, from the Norwegian University of Science and Technology.

Ultra-high temperatures shift the heat transfer process from convection to radiation. But this process has to be as efficient, reliable, stable and safe as possible in order to avoid both accidents, technical failures and energy waste. For that reason, real-time monitoring is crucial.

In Madrid, additional research is being carried out to manufacture the first complete systems. Researchers hope their work could soon turn into a low-cost thermal power station where energy from sustainable sources could be stored in latent-heat batteries in order to provide electricity.

Maximizing conversion of such stored heat into electricity is key. For that to happen, researchers need to pay particular attention to the electrons.

"When a given material reaches a certain high temperature, it releases electrons. Our objective is to help release those electrons in an efficient way at a not too high temperature. In this way, we can maximize the conversion of thermal energy into electricity. The electrons are the conveyors of electricity," says electrical engineer, Daniele Maria Trucchi.

The scientists first prototype is putting the theory into practice. Made from fewer components, the cost of installation and maintenance remains relatively cheap. If tests prove conclusive, researchers think it could go to market.