4. Conclusion

The recovery of unavoidable energy favours technologies that make use of dissipated thermal waste, thereby increasing the power unit's energy efficiency at iso-pollutant emissions. Depending on the engine range and power level, waste heat is extracted from the exhaust, cooling and supercharging circuits, as well as from the external walls. Priority areas for recovery include piston engines, gas turbines, steam turbines, micro-turbines and fuel cells.

Micro-cogeneration enables the production of additional electrical energy, as well as hot and cold thermal energy. The recovery of waste energy is also well suited to individual and collective housing, as well as to the tertiary and hospital sectors. Gas micro-turbines and fuel cells also lend themselves to energy recovery.

Staged supercharging of engines also remains a proven and recognized...