Researchers at the National Renewable Energy Laboratory (NREL) have managed to create a new heat engine that is far more efficient than traditional steam turbines. This new engine has no moving parts and is able to convert heat into electricity with an impressive 40% efficiency.
Similar to a solar panel’s photovoltaic cells, the heat engine is a thermophotovoltaic (TPV) cell that is able to capture high-energy photons from a heat source and convert them into electricity. The engineers claim that it can work with a heat source of between 1,900 to 2,400 degrees Celsius.
The team wants to employ this heat engine in a grid-scale thermal battery. The TPV cell would be able to absorb energy from renewable sources such as the sun and store it in heavily insulated banks of hot graphite. Once this energy is needed, the engine would convert it into electricity and supply it to a power grid.
However, the heat engine has only been successfully demonstrated in small-scale experiments. The researchers are still working on large-scale equipment that could work with fully operational systems.
After that, the next step would be to scale up the system and replace fossil-fuel-driven power plants. This would enable a fully decarbonized power-grid working entirely on renewable energy sources.
Asegun Henry, a professor at MIT’s Department of Mechanical Engineering said:
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.