Feasibility of integrating excess heat from power-to-methanol: Case study of a Danish district heating network

This research investigates the feasibility of integrating excess heat (EH) generated from Power-to-Methanol (PtM) production into district heating (DH) systems, focusing on Sønderborg Municipality in Denmark as a case study. The aim is to determine the economic feasibility and broader energy system benefits of utilising excess heat generated at key stages of the PtM process, including electrolysis, methanol synthesis, and carbon capture. The study develops and evaluates nine main scenarios, along with numerous sub-scenarios, which compare different PtM facility configurations and placements. Specifically, it contrasts the benefits of siting these facilities near renewable energy sources versus closer to district heating systems. By examining these placement strategies, the study provides a detailed analysis of the trade-offs involved in maximising PtM market viability and minimising costs and fuel consumption in the DH systems. It is found that incorporating EH from PtM into DH can lead to reductions in both the operational costs (up to 18 %) and the primary energy consumption (up to 23 %) of the DH supply by displacing fossil fuel and biomass use. Additionally, the sale of excess heat can reduce the levelized cost of energy for PtM up to 10 % under optimal conditions. Importantly, the research demonstrates that strategic placement and effective policy incentives, such as grid tariff exemptions, are critical to enhancing the financial viability of PtM.