National Renewable Energy Laboratory (NREL) researchers have developed a new heat engine that is far more efficient than traditional steam turbines. This new engine has no moving parts and can convert heat into electricity with a whopping 40% efficiency.
The heat engine, like the photovoltaic cells in a solar panel, is a thermophotovoltaic (TPV) cell that can capture high-energy photons from a heat source and convert them into electricity. According to the engineers, it can work with a heat source ranging from 1,900 to 2,400 degrees Celsius.
This heat engine will be used in a grid-scale thermal battery, according to the team. The TPV cell could absorb energy from renewable sources like the sun and store it in heavily insulated banks of hot graphite. When this energy is required, the engine converts it to electricity and supplies it to a power grid.
However, the heat engine has only been demonstrated successfully in small-scale experiments. The researchers are still developing large-scale equipment that will be compatible with fully operational systems.
Following that, the system would be scaled up to replace fossil-fuel-powered power plants. This would allow for a completely decarbonized power grid that relied solely on renewable energy sources.
According to Segun Henry, a professor in MIT’s Department of Mechanical Engineering:
Thermophotovoltaic cells were the last key step toward demonstrating that thermal batteries are a viable concept. This is an absolutely critical step on the path to proliferating renewable energy and getting to a fully decarbonized grid.