Publisher: Journal of Energy Storage
Date: Available online Nov 2023; in Volume 75 (2024), Article 109238
Source title: Retrofit of a coal‑fired power plant with a rock bed thermal energy storage
Authors: María Isabel Roldán Serrano; Kai Knobloch; Stefano Giuliano; Kurt Engelbrecht; Tobias Hirsch
Intro-summary
Open‑access techno‑economic study of a Chilean coal unit retrofitted as a power‑to‑heat‑to‑power “thermal storage plant” using a packed rock bed. The modeled optimum selects 5.27 GWhth (≈8 h) storage and raises steam‑generator inlet from 590 to 650 °C, achieving annual round‑trip efficiency of 34.9% and cutting LCOE by up to 3.4%; minimum LCOE is 88.1 €/MWh, approaching molten‑salt systems. Sensitivity shows a five‑fold storage CAPEX reduction only lowers LCOE ~4% on average, while charge electricity pricing (e.g., green PPAs) is the biggest lever for project viability.