Strategier för deltagande på mFRR-marknaden för kraftvärmeverk : En fallstudie av kapacitetsallokering mellan day-ahead-marknaden och mFRR underosäker ersättning vid Eskilstuna Strängnäs Energi & Miljö

Sammanfattning

This degree project aims to analyse how a combined heat and power plant at Eskilstuna SträngnäsEnergi & Miljö can develop a strategy for participation in the manual Frequency Restoration Reservemarket in combination with the day-ahead electricity market. The study focuses on how uncertainty incompensation levels for the mFRR capacity market and mFRR energy activation market affectscapacity allocation between planned electricity production and balancing services. About the method,the study is conducted as a case study combining literature review, interviews, document analysis, anda quantitative scenario, which is based on modelling in Python. Historical market data for 2024 and2025, heat load data, day-ahead prices, and mFRR price data are used together with technical andoperational constraints from the plant studied. Several scenarios are modelled to compare day-aheadonly operation with different strategies for up- and down-regulation. goThe results show that mFRR prices are more volatile than day-ahead prices and that the value offlexibility cannot be assessed by price comparison alone. The correct electricity focused results showthat the best performing strategy differs between years. In 2024, the day-ahead reference case,Scenario 1, produced the highest net profit, while in 2025, Scenario 5, based on 10 MW of downregulation, produced the highest net profit. Scenario 5 also showed clear operational advantages byreducing actual electricity production after activation, increasing useful heat production, and loweringthe need for support and peak-load resources. The study concludes that the most suitable strategy forESEM is not to maximise mFRR participation in all hours, but to use a selective and balanced capacityallocation strategy. Day-ahead should remain the planning basis, while mFRR should be used whenthe expected value justifies the opportunity cost, the technical delivery capability is secured, and theheat system, including the accumulator, provides sufficient operational margin.