In the building heating/cooling sector resorting to the use of renewable energy is difficult, as there is a strong seasonal difference between the periods of greater demand for thermal energy compared to those of greater supply. A possible solution to effectively address this misalignment is to use seasonal storage systems. Among these, the ATES – Aquifer Thermal Energy Storage systems have significant potential as they represent an alternative means of conserving energy at low costs. Despite their potential, the development of ATES systems has faced numerous issues due to a fragmented regulatory framework that does not deal with all the necessary aspects to create robust and reliable systems that ensure a low environmental impact. In this report, directions are provided for the drafting of Guidelines aimed at promoting the development of ATES systems on the national territory: on the one hand, this would stimulate the development of ATES systems; on the other hand, the subsoil and the environment would be protected.
In this document, a survey of the reference standards available both in Europe and at national level has been carried out. Below is an overview of the possible impacts that the creation of ATES systems could generate on the water system and the underground environment. Specifically, the hydraulic, thermal, and water quality impacts were analyzed, as well as the main effects on the competing uses of the water resource and on the long-term heat balance, hinting at any implementable measures to limit the impacts.
In addition, for all the evolutionary phases that distinguish a potential ATES system (starting from the feasibility studies up to the decommissioning of the plant) this report addresses the main aspects that should be considered during the development of the regulations.
The analyses carried out have highlighted how essential it is to prepare specific rules for this sector as the lack of clear and well-founded strategies inevitably inhibits the development of promising and effective technologies for the diffusion of ATES systems.