The efficiency of the machines in our modern world is defined by the amount of thermal energy that can be captured as mechanical energy for production commercial use. It is mechanical energy that spins an electric generator to make electricity or propels cars, or planes or ships. It is mechanical energy used for commercial purposes. The more mechanical energy a machine captures, the more efficient and commercially attractive it is. That efficiency is called the thermal efficiency of a machine and its financial analogue is called “Return-on-Capital.
The problem with conventional power
Thermal efficiency varies with the temperatures of thermal energy, high temperature equals high efficiency, low temperature equals low efficiency. Thermal efficiency translates directly to financial efficiency and commercial performance reflected in measures such as return-on-capital.
Coal, oil and natural gas fired power plants operate at high efficiency because coal, oil and natural gas combustion creates heat at high temperature (585°C steam). They have a thermal efficiency that exceeds 45% and generate inexpensive electricity. But burning fossil fuels creates air pollution that contributes to pulmonary diseases and climate change.
Conventional nuclear power plants are carbon-free but inefficient machines, because conventional nuclear technology generates heat at low temperature (290°C steam). They have a thermal efficiency that is low; 30% for small plants, 33% for large plants.
The IMSR difference
IMSR cogeneration plants are efficient machines. The IMSR generates heat at high temperature (585 degree C steam). They have a thermal efficiency of 44%, a near 50% efficiency improvement. Conventional nuclear power plants use water as the reactor coolant and must operate at low temperatures.
In addition to cost and Return-on-Capital, thermal efficiency impacts all aspects of plant operation including the efficiency of land-use, material use, and waste production.