Techno-economic analysis of steam generation and energystorage via carnot battery and heat pump: a study based on thelevelized cost of heat and storage
The Carnot battery is a long-duration energy storage system (ESS) that converts and stores electrical energy in the form of thermal energy. The stored heat can later be reused for electricity generation, making the Carnot battery a promising technology for retrofitting coal-fired power plants into green storage plants under carbonneutral policies. Furthermore, the Carnot battery can also be utilized for industrial steam production. This study compares the economic feasibility of steam production using the Carnot battery and heat pump technologies based on the Levelized Cost of Heat (LCOH). In this research, LCOH [$/ton] is used to evaluate the cost of producing industrial steam. The Carnot battery enables thermal energy storage using low-cost nighttime or surplus electricity, resulting in an LCOH less than half of the current industrial steam price. Similarly, heat pump-based steam generation using surplus electricity achieves comparable cost reductions. However, when operated during daytime hours, the heat pump yields an LCOH approximately 10% higher than the market steam price. This study also evaluates the economic feasibility of electricity storage when retrofitting coalfired power plants with Carnot batteries, based on the Levelized Cost of Storage (LCOS). Additionally, a comparative analysis of combined heat and power (CHP) plant retrofitting was conducted. The economic feasibility of steam production and electricity storage was evaluated according to the steam-to-electricity output ratio, based on both LCOH and LCOS. It was found that retrofitted CHP plants can achieve a lower LCOS compared to standalone coal plant retrofits. Overall, the comparative analysis of LCOH and LCOS in this study demonstrates that thermal energy storage and supply systems based on the Carnot battery and heat pump will become increasingly competitive in the context of global decarbonization and electrification trends.