Power-to-heat plants in district heating and electricity distribution systems: A techno-economic analysis

This paper investigates the Power-to-Heat energy conversion process carried out by heat pumps connected to a district heating network used to provide heat to the heating sector and, at the same time, to provide flexibility for the electricity sector. The aim of this work is to analyze from a techno-economic point of view the flexibility potential of this solution used to absorb the over-generation of Variable Renewable Energy Sources in the dis-tribution system. A scenario, based on the electric distribution system and the district heating distribution system of the city of Turin, was created to carry out this type of study. The results showed that, flexible use of these Power-to-Heat systems can be exploited to shift part of electric loads in periods of renewable over-generation, with significant benefits from an economic point of view. Furthermore, the position of Power-to-Heat systems within an electricity distribution network has a significant impact; to make the most out of the flexibility of these plants, they should be placed in those areas of the network that present the greatest local over-generation of renewables. The use of heat pumps will be necessary for the energy transition thanks to the high conversion efficiency. However, in order to fully exploit all the benefit that this technology can offer its flexibility cannot be ignored.