MOST from the sun: The sun is the largest source energy after controlled nuclear fusion, but a clear sky is always needed too.
To have solar energy 24 hours a day, a team of scientists from Chalmers University of Technology of Sweden in Gothenburg develops a liquid energy storage medium that can charge from the sun on demand, but also to transport it.
Chalmers' team has been developing variations of their system, called Molecular Solar Thermal (MOST), for more than six years. The project appears to differ from other solar energy storage efforts as it uses heated salts and reverse exothermic reactions. The MOST system can store energy directly in the bonds of an organic chemical.
To do this the scientists expose a hydrocarbon called norbornadiene to light. This changes the chemical bonds of the hydrocarbon, turning it into a quadricyclane. Her change temperatures of tetracyclane (quadricyclane) and n report of in a catalyst reverses the effect and releases energy in the form of heat.
According to the team, the current system converts 1,1% of sunlight directly into chemical bonds, which is 100 times more efficient than the first version of the system they tested in 2013. The researchers' system at the time could only handle 0,01%.
In addition, the new liquid storage system replaces ruthenium, a rarity metal, with carbon cells that are much cheaper. The researchers also report it can go through over 140 storage and power cycles without noticeable energy loss.
"This technique means we can store solar energy in chemical bonds and release it as heat whenever we need it," said team leader Kasper Moth-Poulsen.
"The combination of chemical energy storage with solar panels with water heating allows the conversion of more than 80% of incoming sunlight."
The research was published in the journal Energy & Environmental Science.
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