The development of a significant amount of economically and technically efficient storage infrastructure to enable the integration of non-programmable renewable energy sources into the electricity grid is essential to address challenges such as load balancing, frequency regulation and the need for flexible generation of energy reserves. Pumped Hydro Energy Storage (PHES) plants, a long tradition in Italy, can be a promising solution if new plants suitable for this purpose were to be built (traditional PHES and Seawater PHES plants).

To investigate which possible actions can be concretely implemented a Geographic Information System (GIS) procedure was developed and applied across the entire Italian territory. This procedure was further refined using advanced GIS object-based image analysis software to pinpoint areas with ideal topographical features for constructing new reservoirs.

An innovative method was used to consider the impacts of the present reservoir silting, which forms part of the potential PHES taking into account the average erodibility of the soils and the sediment contributions from the reservoir basin. All costs were estimated to propose a future plant economic indicator, which also considered siltation conditions.

Finally, the most promising plants, identified using this indicator, were proposed. Following an initial screening of 574 currently existing reservoirs, 29 potential PHES were identified deemed suitable, based on considerations of cost/power ratio and siltation incidence. The total Italian potential installable power amounts to approximately 10 GW, with Sardinia emerging as a key region with 4 GW of potential capacity distributed across 11 selected sites.

Concerning the Seawater PHES an enormous seawater pumped potential of approximately 20 GW, with 39 possible configurations with and specific cost value per unit of power lower than 2,5 M€/MW could be realized.