Scientists at Sweden’s Chalmers University of Technology have shown effective storage of solar energy in a chemical liquid. The stored energy can be transported and released at any time as heat.
Scientists consider the sun is the energy source of the future. But one challenge is that it is difficult to store solar energy and deliver the energy ‘on demand’.
A research team from the Chalmers Technology University in Gothenburg, Sweden, has shown that solar energy can be transformed directly into energy stored in chemical fluid bonds also called molecular solar thermal system.
The liquid chemical enables the stored solar energy to be stored and transported and released on demand, with the storage medium being fully recovered. The process is based on the norbornadiene organic compound, which transforms into quadricyclane when exposed to light.
‘The technique means that that we can store the solar energy in chemical bonds and release the energy as heat whenever we need it.’
‘Combining the chemical energy storage with water heating solar panels enables a conversion of more than 80 percent of the incoming sunlight.’says Professor Kasper Moth-Poulsen, who is leading the research team.
More than six years ago, the research project was initiated in Chalmers and the research team contributed to a first practical presentation in 2013. At the time, the efficiency of solar energy conversion was 0.01 percent and the costly element ruthenium played an important role in the compound.
Now, four years later, the system is storing 1.1% of incoming sunlight as latent chemical energy — an improvement of a factor of 100. Ruthenium has also been substituted by carbon-based elements that are much cheaper.
‘We saw an opportunity to develop molecules that make the process much more efficient,’ . ‘At the same time, we are demonstrating a robust system that can sustain more than 140 energy storage and release cycles with negligible degradation.says Moth-Poulsen