For the last couple of decades, scientists have since long been grappling with the twin problems of how to efficiently store solar energy for later use and what to do with the carbon dioxide that has been captured and sequestered from coal plants.
Scientists working at General Electric may have possibly found answers to both problems at once. They have come up with the idea of using CO2 as a giant battery to hold excess energy. They want to heat salt using a concentrated mirror array like the one that exists at the Ivanpah solar plant in California while the CO2, which is stored underground is cooled to a solid dry state using excess power from the grid.
During peak hours, especially when the sun is down, the heated salt can be tapped to warm up the solid CO2 to a state which is neither solid nor gas. With the heated salt entering this "supercritical" state the substance is funneled into a purpose built turbines which will, naturally generate electricity.
A prototype made by GE dubbed as the "sunrotor" can generate enough electricity to power 100,000 homes, according to GE.
Significantly, this design could also make gas fired power plants more efficient. As per Stephen Sanborn, a senior GE engineer, this design could boost the output of an existing system by more than 50% and at the same time slash the current $250 per megawatt-hour to $100.
"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," said Sanborn. Additionally, this system would also return 68% of the stored energy back to the grid, in comparison to the current 61%in gas-fired power plants.
The system that GE has come up with is obviously complex and demands a great deal of expertise in heat transfer technology, refrigeration, chemical engineering, and energy storage, all of which are with GE.
Looking ahead, Sanborn thinks this idea of GE could see commercial reality in as little as 5 to 10 years.
"We're not talking about three car batteries here. The result is a high-efficiency, high-performance renewable energy system that will reduce the use of fossil fuels for power generation," said Sanborn.
Scientists working at General Electric may have possibly found answers to both problems at once. They have come up with the idea of using CO2 as a giant battery to hold excess energy. They want to heat salt using a concentrated mirror array like the one that exists at the Ivanpah solar plant in California while the CO2, which is stored underground is cooled to a solid dry state using excess power from the grid.
During peak hours, especially when the sun is down, the heated salt can be tapped to warm up the solid CO2 to a state which is neither solid nor gas. With the heated salt entering this "supercritical" state the substance is funneled into a purpose built turbines which will, naturally generate electricity.
A prototype made by GE dubbed as the "sunrotor" can generate enough electricity to power 100,000 homes, according to GE.
Significantly, this design could also make gas fired power plants more efficient. As per Stephen Sanborn, a senior GE engineer, this design could boost the output of an existing system by more than 50% and at the same time slash the current $250 per megawatt-hour to $100.
"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," said Sanborn. Additionally, this system would also return 68% of the stored energy back to the grid, in comparison to the current 61%in gas-fired power plants.
The system that GE has come up with is obviously complex and demands a great deal of expertise in heat transfer technology, refrigeration, chemical engineering, and energy storage, all of which are with GE.
Looking ahead, Sanborn thinks this idea of GE could see commercial reality in as little as 5 to 10 years.
"We're not talking about three car batteries here. The result is a high-efficiency, high-performance renewable energy system that will reduce the use of fossil fuels for power generation," said Sanborn.