The idea is to develop a heat pump which is able to revert its cycle and to produce electricity with the same components (Rankine cycle). The, so-called, reversible HP/RC system can be integrated with a thermal energy storage and a district heating to obtain a Carnot battery. The Carnot battery can use excess renewable electricity to produce and store thermal energy with a high coefficient of performance (thanks to heat integration). This thermal energy can then be discharged either in the district heating directly when needed or in the Rankine cycle to produce electricity when renewable production is insufficient. This project applies the Carnot battery to a district heating but can be very efficient in terms of sector coupling in many other applications…
The final user benefits from:
-Electrical peak shaving (the excess electricity is stored to restore electricity when peak of consumptions appear).
-Thermal peak shaving (the excess electricity is converted into thermal energy to restore it during the peak of thermal consumption).
-Use of potential low-grade heat (Waste heat or heat from district heating can be integrated to increase the COP of the heat pump and improve the global efficiency of the system).
-The Return On Investment (3 years) is over 10% with conservative hypotheses.