Supercritical Carbon Dioxide Turbine

Supercritical Carbon Dioxide Turbine: A Small Solution To A Big Problem

Currently, power plants primarily use steam turbines that are based on technology developed in the 19th century. These turbines can vary in size from small units generating less than 100 kilowatts to large ones producing over 250 megawatts. In power plants, these turbines are often extremely large, comparable in size to a bus or even larger.


In recent years, researchers have been testing a new type of turbine that uses supercritical carbon dioxide instead of steam, as it is more efficient in terms of energy.

According to the US Department of Energy, new supercritical carbon dioxide turbines are expected to reduce energy consumption at power plants by 10%. Additionally, these turbines have a smaller size compared to traditional steam-driven turbines, leading to improved manufacturing efficiencies throughout the supply chain.

In comparison, the Energy Department states that if a 20-meter steam turbine is replaced with an sCO2 turbine, its size would decrease to only one meter.

“Above the critical point, CO2 does not change phases (that is, change from gas to liquid). Instead, it undergoes a change in density in even small shifts in temperature and pressure,” the Energy Department explains. “This property allows a large amount of energy to be extracted at a high temperature, using equipment that is relatively compact.”

Supercritical carbon dioxide turbines, similar to steam turbines, can be used with different types of fuel. The Energy Department plans to use them in coal and gas power plants to improve energy efficiency by making carbon capture more efficient in fossil-fueled power plants.

The connection between supercritical carbon dioxide turbines and concentrating solar power is even more exciting in terms of saving the planet.

The Energy Department’s showcase for sCO2 technology is taking shape in the form of a new $155 million, 10 megawatt-equivalent demonstration power plant. In the latest update, the team has just marked the completion of the mechanical work on the system, including new turbines that are about 1/10 the size of a conventional steam turbine.

Though only about the size of an office desk, household refrigerator, pony, credenza, or golf cart, the new turbines are powerful enough to generate the electricity equivalent of 10,000 typical homes. If all goes according to plan the STEP (Supercritical Transformational Electric Power) plant will be fully operational early in 2024.

Reference- Clean Technica, STEP Program, Interesting Engineering, Forbes, US Department Of Energy Newsroom