Abstract
This work is related to the Flexynets project, pursuing the realization of a neutral-temperature (15-25 °C) district heating and cooling network based on heat pumps. In this concept, heat pumps substitute heat exchangers in residential substations. This approach would allow the integration of a large number of waste heat sources, at temperatures usually not accessible for traditional networks. The additional costs given by heat pumps would then be repaid by the availability of cheap heat, by reduced thermal losses, and by the consequent possibility to exploit long-term storages.
Clearly, the use of heat pumps implies the simultaneous presence of thermal and electrical energy consumptions. Furthermore, the heating/cooling duality of the network suggests the shift from the producer/consumer model to the prosumer concept, as in electrical smart grids. These aspects, while yielding more operational flexibility, increase the complexity of the corresponding market models, with different possible prices for buying/selling thermal/electrical energy.
Considering energy prices, reference technologies, and a reasonable performance range for heat pumps, we identify simple bounds for the admissible costs of a Flexynets network, under the constraint of having final user prices no higher than for current reference options. Though the obtained values are rather demanding bounds considering the present energy costs, they still offer margin for the feasibility of the proposed approach.