Now molecules can store solar energy forever
In a path breaking achievement, scientists at MIT and Harvard University have come up with a method to store solar energy in molecules and then use the clean energy to heat homes, water or used for cooking.
The molecules can store the heat forever and can be used again and again without emitting any greenhouse gas. The scientists have called this phenomenon photo switching.
"Some molecules, known as photoswitches, can assume either of two different shapes, as if they had a hinge in the middle," MIT researchers said in statement about the paper published in the journal Nature Chemistry. "Exposing them to sunlight causes them to absorb energy and jump from one configuration to the other, which is then stable for long periods of time."
You can liberate the stored energy by exposing the molecules to a small amount of light, heat or electricity as they emit heat when switch to some other shape. "In effect, they behave as rechargeable thermal batteries: taking in energy from the sun, storing it indefinitely, and then releasing it on demand," the scientists said.
A photoswitching substance called an azobenzene was used by researchers during study. This substance was used to attach the molecules to substrates of carbon nanotubes.
"It would also enable charging by flowing the material from a storage tank through a window or clear tube exposed to the sun and then to another storage tank, where the material would remain until it's needed. That way one could stockpile the charged material for use when the sun's not shining," Timothy Kucharski, the paper's lead author and a postdoc at MIT and Harvard, said.