No matter how abundant or renewable, solar power has a thorn in its side. There is still no cheap and efficient long-term storage for the energy that it generates.
The solar industry has been snagged on this branch for a while, but in the past year alone, a series of four papers has ushered in an intriguing new solution.
Scientists in Sweden have developed a specialised fluid, called a solar thermal fuel, that can store energy from the sun for well over a decade.
"A solar thermal fuel is like a rechargeable battery, but instead of electricity, you put sunlight in and get heat out, triggered on demand," Jeffrey Grossman, an engineer works with these materials at MIT explained to NBC News.
The fluid is actually a molecule in liquid form that scientists from Chalmers University of Technology, Sweden have been working on improving for over a year.
This molecule is composed of carbon, hydrogen and nitrogen, and when it is hit by sunlight, it does something unusual: the bonds between its atoms are rearranged and it turns into an energised new version of itself, called an isomer.
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