Economic Analysis of Mobile Thermal Energy Storages as Complement to District Heating

Abstract Urban areas are increasingly supplied by district heating networks (DHN) because this technology is reliable, provides easy handling for the customer and contributes to the required reduction of greenhouse gas emissions if it is operated from renewable sources. Waste heat from the industrial sector can serve as such, however, industrial plants are often not in the meaningful range of DHN, as they are mostly located in the periphery. For this reason, the application of mobile thermal energy storages (M-TES) is investigated by the present research work. M-TES systems are technically capable of exchanging heat between a DHN and heat sources or heat sinks, as previous studies have shown, but economic viability could not be reached with former energy prices. However, geopolitical incidents of 2022 resulted in massive fluctuations on the energy markets and unpredicted price increases. Therefore, this paper provides an updated analysis of M-TES, considering the premises of 2022. An economic model according to VDI2067 was developed for calculating the costs of transported heat for different storage technologies and materials. Moreover, transportation by a Diesel driven truck was compared to an electric driven one. The updated analysis yielded economic feasibility for specific M-TES configurations, achieving minimum heat costs of € 89.5 per MWh. This is equivalent to a reduction of 40.3 % related to the prices of conventional district heating in Austria by end of 2022.