CO₂ in its supercritical state has uniquely useful properties. In this state, at pressure and temperature conditions which can be relatively easily achieved, the CO₂ has the fluidity of a gas but the density and the low compressibility of a liquid.

Because of these properties, sCO₂ allows for more compact components in the power plant, including heat exchangers and turbomachinery. For example, the size of the turbine can be dramatically reduced by up to 85%. This leads to lower cost and space requirements for the plant.