TES Model for Hybrid Energy System Analysis

Long-duration energy storage (LDES) is essential for efficiently harnessing renewable energy. While electrochemical energy storage technologies have been increasingly deployed, they often face challenges due to high costs and limited mineral resources. Thermal Energy Storage (TES) offers a promising, cost-effective, and location-independent solution for LDES by storing energy as heat in inexpensive materials. A dynamic TES simulation tool within Flownex was developed to predict the TES outlet temperature for varying inlet conditions within a typical combined heat and power (CHP) system. The application of the dynamic TES model was demonstrated by successfully simulating the transient behaviour of a gas turbine cogeneration system for a 950°C gas turbine inlet temperature and ~18h TES energy storage duration. The model was used to evaluate the economic viability of a TES gas turbine cogeneration system compared to a lithium-ion (Li-ion) battery system for delivering the same output. An economic comparison over a 30-year project lifespan highlights the advantages of TES for LDES.