General Electric Wants to Create Large Solar Batteries Using Pollution

Solar energy is incredibly practical and relatively easy to obtain, but it’s definitely not easy to store for later use. Scientists have been trying to come up with a solution to this problem for quite a while now, and it looks like things are finally looking up. A team of researchers from General Electric have come up with an idea on how to store solar energy and what to do with leftover CO2 sequestered from coal plants. Apparently, the solution comes in the form of a giant battery that would hold all of that excess energy, but how exactly would this battery work? Well, the main idea is to use solar power and a concentrated mirror array in order to heat up salt, while CO2 stored underground is cooled to a solid dry ice state with the help of excess grid power.

At peak times when the grid requires a boost in electricity, the heated salt can warm up the CO2 and cause it to enter a supercritical state between gas and solid, at which point it can be funneled into special GE turbines that can generate power rapidly. Dubbed “Sunrotor,” the project could potentially generate enough power for 100,000 homes. Moreover, the system could also be powered using wasted heat generated by gas-fired power plants, in which case it could become even more efficient. According to  Stephen Sanborn, a senior engineer over at GE, the system could reduce costs from $250 per megawatt-hour to $100, and he explained exactly why:

“It is so cheap because you are not making the energy, you are taking the energy from the sun or the turbine exhaust, storing it and transferring it.”