Engineers Develop Engine That Converts Heat to Electricity with 40% Efficiency

Researchers have developed a new heat engine that could take on the traditional steam turbine in terms of energy efficiency. According to a recent press release, engineers at MIT and National Renewable Energy Laboratory (NREL) have created a heat engine that features zero moving parts. Researchers say their tests demonstrate that the new technology is able to convert heat to electricity with more than 40% efficiency, which is superior to the steam turbine. A traditional steam turbine uses thermal energy from steam generated from a heat source and converts it to mechanical output. While this technology has selective use cases today, it is said that its thermal efficiency is often higher than that of a reciprocating engine. The new heat engine has been described as a thermophotovoltaic (TPV) cell that’s “similar to a solar panel’s photovoltaic cells” in that it captures photons from heat sources before converting them into electricity. In this case, the high-temperature source is where the new TPV cell has a leg up on the traditional steam turbine, which long depended on moving parts that would max out at certain temperatures. In this case, the TPV cell would be capable as a grid-scale thermal battery. The release says the new system absorbs extra energy from sources such as the sun and then is able to capture that energy in hot graphite. Then, on overcast days when energy is required, the TPV cells convert the heat to electricity.