Foundations
1698~1712
Steam Engine
Modern Max. Efficiencies: 10–15%
Early steam engines laid the groundwork for mechanical power and industrialization.
1551~1928
Turbine
Average Modern Max. Efficiencies: 35-40%
Compact turbines improved efficiency and now dominate aircraft propulsion. Combined natural-gas & steam turbines may attain 56% total large-scale power plant efficiency at full load.
Piston Engine Era
1794~1876
Otto Cycle (4-Stroke) Engine
Modern Max. Efficiencies: 18–40%
The Otto engine powers personal transportation and small-scale electric generation.
1895
Diesel Engine
Modern Max. Efficiencies: 43–55%
High efficiency enabled Diesel engines to become a workhorse for heavy-duty and backup power applications.
Solid-State Power from Heat & Fuels
2025
PowIRgen – ThermoPhotoVoltaic (TPV) Cell
Max. Efficiencies: 53–65%
PowIRgen TPV once again rewrites the landscape of global mobile and stored power. Efficiencies are highest at aircraft cruising altitudes and in thermal batteries. All solid-state generation yields low noise and near-zero maintenance.
