The Integration of a Photovoltaic/Thermal System into a District Heating System
K. Sredenšek(1,2), J. Počivalnik(1), D. Kuhar(1), B. Stergar(1), E. Simonič(1), G. Štumberger(2), S. Seme(1,2) 1. Faculty of Energy Technology, University of Maribor, Krško, Slovenia 2. Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia 2026-06-27

Abstract

District heating systems are increasingly transitioning toward low-carbon and renewable energy sources in response to climate and energy policy objectives. Among emerging technologies, photovoltaic/thermal systems represent a promising solution by enabling the simultaneous production of electrical and thermal energy. This paper investigates the performance and economic feasibility of a photovoltaic/thermal system integrated with a heat pump as a renewable heat source for low-temperature district heating applications. Two system configurations are analysed: a photovoltaic/thermal system coupled with a water-to-water heat pump and a conventional photovoltaic system coupled with an air-to-water heat pump. The systems are evaluated based on electrical energy production, heat pump performance, energy self-sufficiency, and investment profitability. The economic assessment is based on a monthly electricity billing scheme that accounts for the balance between produced and consumed electrical energy, as well as revenues from surplus electrical energy fed into the grid. In addition, both configurations incorporate a battery storage system to enhance operational stability and ensure a reliable electrical energy supply to the heat pump. The results demonstrate the technical and economic potential of photovoltaic/thermal systems for improving the efficiency, flexibility, and sustainability of low-temperature district heating networks.

Key words: photovoltaic/thermal system, electrical energy, thermal energy, district heating

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