Influence of supply temperature and booster technology on the energetic performance and levelized cost of heat of a district heating network with central heat pump

The development of new low-temperature district heating networks in existing urban areas can accelerate the replacement of fossil-fuel-based heating systems by collective heating using electricity or renewable heat sources . Buildings can either be connected to the network in their current, non-refurbished state for rapid deployment or be refurbished before connection to achieve maximum energy efficiency. To assess the difference between these two strategies, this paper examines eight low-temperature district heating concepts with central heat pump, comparing their energy use and levelized cost of heat . The study includes four scenarios for each strategy, considering supply temperatures ranging from 10 °C to 75 °C. Heat pumps or electric heaters are used as booster technology when the network supply temperature is too low for space heating or domestic hot water purposes. The use of booster heat pumps shows the highest seasonal coefficient of performance for both refurbished (4.61) and non-refurbished buildings (3.43). However, booster technologies result in the highest levelized cost of heat, driven mainly by the high investment cost of the network and booster units. Lowest levelized cost of heat of 213 €/MWh th is obtained for non-refurbished buildings at 75 °C and 297 €/MWh th for refurbished buildings at 55 °C without boosters. • Study on small-scale district heating concepts with central heat pump in urban areas. •Development strategies with non-refurbished and refurbished buildings are compared. •Seasonal coefficient of performance of the network reaches up to 4.61. •Combination of central and booster heat pump results in highest efficiency. •A network at 75 °C with non-refurbished buildings is most financially feasible.