Volume 61

Integrated Operation of Combined Heat and Power, Underground Thermal Energy Storage, and Batteries in Nordic Electricity Markets Helen Saragih, Kristian Sandström, Stavros Vouros, Konstantinos Kyprianidis

Abstract

The growing share of renewables in the power system has increased the risk of supply and demand imbalances, leading to more frequent grid frequency deviations. To manage this, flexible resources are needed to help close this gap. Batteries have already proven to be a mature technology for energy arbitrage and are financially rewarded for providing reserves that support grid balancing. At the same time, the rising penetration of renewables into the power system has reinforced the link between heat and electricity sectors. Combined Heat and Power (CHP) sits at the intersection of these two systems and plays a key role in supporting this interaction. However, these two technologies operate differently, and their joint potential remains underexplored. This paper presents a mixed-integer linear optimization (MILP) model that maximizes revenue from multi-market participation under current market rules. Two case studies of different system configurations are compared. The results highlight the significance of high-value frequency markets and complementary roles of CHP and batteries in market participation.

Keywords sector coupling, combined heat and power, batteries, flexibility, multi-market participation