If we could eliminate friction, what would be the potential efficiency of a fossil-fuel-burning electricity-generating power plant?

To determine the potential efficiency of a fossil-fuel-burning electricity-generating power plant without friction, it's important to understand the thermodynamic limitations inherent in energy conversion processes, especially ones involving combustion.

Fossil fuel power plants operate on the principles of heat engines, which convert the thermal energy produced by burning fuel into mechanical energy and, subsequently, electrical energy. However, no heat engine can reach 100% efficiency due to the Second Law of Thermodynamics, which states that energy systems will always experience some form of energy degradation in the conversion process.

In practical terms, efficiency is often calculated using the Carnot efficiency equation, which is based on the temperatures of the heat source and heat sink. For most fossil fuel power plants, the maximum theoretical efficiency is generally in the range of 30-50%, depending on factors like the type of fuel and the technology used. Even with friction eliminated, there are still inherent losses from things like heat escaping into the environment and the unavoidable entropy produced during the conversion process.

While eliminating friction would reduce some mechanical losses in the system, it would not affect the fundamental thermodynamic limitations of the heat engine cycle utilized by the power plant. Therefore, it indicates that the efficiencies of around 50% are realistic estimates