MIT scientists have now designed a system that could store renewable energy such as the wind and solar power, deliver it back into an electric grid on demand. The system which is described in the Environmental Science and Journal of Energy may be designed to power a small city not just when the sun is up, or the wind is high but around the entire clock.
The new design stores heat which is generated by excess electricity from wind or solar power in large tanks of white-hot molten silicon, and then converts the light from the glowing metal black into electricity when it is much more needed.
The researchers from the MIT in the US estimates that such a system that would be vastly more affordable than lithium-ion batteries which have been proposed as a viable, though expensive, a method to store renewable energy. They also estimate that the system would cost about half as much as pumped hydroelectric storage, which is the cheapest form of grid-scale energy storage to date.
“Even if we wanted to run the grid on renewables right now we couldn’t because you’d need fossil-fuelled turbines to make up for the fact that the renewable supply cannot be dispatched on demand,” said Asegun Henry, Associate Professor at MIT. “We are developing a new technology that, if successful, would solve this most important and critical problem in energy and climate change, namely, the storage problem,” Henry said. The new storage system stems from a project in which the researchers looked for ways to increase the efficiency of a form of renewable energy known as concentrated solar power.
“The reason that technology is interesting is, once you do this process of focusing the light to get heat, you can store heat much more cheaply than you can store electricity,” Henry said.