Electrical energy storage using a supercritical CO2 heat pump

Abstract

This work proposes a new Pumped Thermal Energy Storage (PTES) configuration that works with supercritical CO2 as the working fluid and molten salts as the thermal storage fluid. The net work generated by this novel proposal is 12.46 MW in the load and 10 MW in the discharge, reaching an efficiency of 80.26%. In addition, a techno-economic optimization is carried out to quantify the discounted cost per unit of energy discharged from this storage technology with a value of 0.116 €/kWh. This technology places this technology as a strong candidate for the future energy solution due to its low wear per duty cycle and easy power scalability. It presents a lower initial cost than other technologies with low LCOS.

Keywords

• Brayton cycle
• Heat Pump
• Renewable energy
• Supercritical CO2
• Thermal storage