Abstract
Electrification of industrial process heating is crucial for decarbonization but can increase both operational costs and power grid strain. Thermal energy storage (TES) offers a flexible solution to this challenge, yet its economic viability depends heavily on multi-market participation. The economic potential of TES integration is assessed for distinct operational strategies that progressively incorporate day ahead spot price arbitrage, grid-tariff peak shaving and frequency restoration reserve participation into the energy system operation optimization. Using a full year of hourly operational data, TES-supported electric boiler operation is optimized within an industrial context. The results demonstrate that optimizing solely for spot price arbitrage raises capacity-related costs due to high power peaks. However, co-optimizing for grid tariffs reduces load variability, preserving the symmetric flexibility required for reserve market participation. Further co-optimizing with respect to reserve market participation yields additional savings - up to 58% for a 25 MWh TES, significantly lowering the investment threshold and enhancing the competitiveness of electrified industrial heating.