Economic Analysis of Electrode Boilers for District Energy Business: A Comparison of CHP-coupled and Independent Models

This study analyzes the economic feasibility of electrode boilers as Power-to-Heat in Korean district energy under two configurations. BM 1 couples an electrode boiler to a CHP plant, easing its heat burden and raising electricity sales margin; a breakeven price condition derived from generation cost, boiler efficiency, and reserve market participation was applied to actual KPX system marginal price data. BM 2 is a standalone electrode boiler with thermal storage, buffering the gap between heat production and demand; net present value was simulated from regional heat demand and daily prices, with sensitivity analysis on storage capacity. Under variable-cost criteria alone, breakeven was rarely achieved, but adequate reserve prices restore viability at average market prices. It peaked at a specific storage capacity relative to maximum regional heat load, with diminishing returns beyond. Reserve participation and storage sizing are thus decisive for viability and market design.