Analysis of low‐temperature pumped thermal energy storage systems based on a transcritical CO₂ charging process

Pumped thermal energy storage (PTES) is a technology for intermediate of electrical in the form energy. In this work, PTES systems based on transcritical CO2 charging process are investigated. A two-zone water tank with temperature 115°C used as storage. For discharge, an Organic Rankine Cycle (ORC) and, alternatively, heat engine The considered concepts modelled and simulated stationary processes using EBSILON Professional software. scaling input power 5 MW. Using ORC working fluid R1234yf discharging results highest round-trip efficiency 36.8%. component costs different configurations estimated cost functions. On basis this, levelized (LCOS) calculated. configuration has lowest LCOS 59.2 €cents (kWh)−1. addition, technological maturity determined readiness level scale. There no prototypes investigated yet. Therefore, further investigations must be carried out to implement future.