Comparative market price and emission driven electricity dispatch analysis for sCO2 cycle based thermally integrated pumped thermal energy storage system

Large-scale energy storage is essential for integrating increasing shares of renewable energy into power grids. Pumped Thermal Energy Storage (PTES), particularly Thermally Integrated PTES (TI-PTES), offers advantages such as long lifespan, fast response, and flexibility, along with external heat source integration. Traditionally, PTES dispatch studies focus on maximizing profitability, which often leads to energy storage from CO₂-emitting sources rather than purely from renewables. This study investigates the optimal dispatch strategy for a supercritical carbon dioxide (sCO₂) thermal cycle-based TI-PTES across various European markets using a Mixed Integer Linear Programming (MILP) model. The primary objective is to evaluate the economics of TI-PTES optimized for CO₂ emission minimization and compare it with conventional profit-maximizing dispatch strategies based on electricity market prices.

For selected EU energy markets, key indicators such as payback period, net present value (NPV), levelized cost of electricity (LCOE), and displaced CO₂ emissions are analyzed for price-based vs. CO₂ emission-based dispatch to assess the financial viability and environmental impact of TI-PTES. Study shows annual round-trip efficiency of 105 % for Finland and 101 % for Germany, as compared to the 112 % of the electric RTE set for the model. The payback periods for only Germany comes out to be achievable during the span of the plant life of 25 years under the current market price scenarios. However, with increased volatility from 20 to 100 %, the payback period for the same market can decrease 20–60 % of the current value. Similarly, the study further proposes a novel hybrid dispatch strategy that incorporates both economic profitability and emission minimization by assigning appropriate weights to each objective. The optimal weighting varies for each energy market to achieve the most effective results. The hybrid dispatch approach positions TI-PTES as both an economically and environmentally viable solution for energy storage and grid integration.