The exploitation of increasing shares of electricity from Non-Programmable Renewable Sources (NPRS), particularly wind and photovoltaic, and the concomitant reduction in production from fossil fuel power plants, represents a positive shift in greenhouse gas emissions. However, it raises some concerns regarding the controllability and stability of the power system due to the variability and forecast uncertainty of these sources, their operating mode (without upward power margins, to fully utilize the primary source), and some technological aspects (connection to the grid via electronic converters, limited or no contribution to system inertia and short-circuit currents).
Hydroelectric pumped storage plants are significant flexibility resources for improving system performance. There is a need to develop procedures and methodologies for locating and characterizing the sustainability of new pumped storage plants, consisting of existing large reservoirs and new reservoirs situated at higher altitudes. This work presents a methodological approach based on Multi-Criteria Analysis (MCA) for the characterization and ranking of potential pumped storage plants aimed at providing new flexibility resources for the power system.
The proposed methodology considers criteria such as the availability of plant flexibility and the system’s need for flexibility, economic aspects, and ease of approval and implementation of the plants, also considering the effects of overlap and proximity to protected areas. Indicators quantified include installed capacities, drought issues, congestion and overgeneration management capacities of local renewable energy production, costs and benefits to the local and national community, overlaps and proximities to protected areas, impacts of construction works, etc. This methodology was applied to the case of Sardinia, categorizing 27 potential pumped storage plants according to a ranking derived from the mentioned criteria and 21 indicators. The analysis identified the pumped storage plant formed by the reservoir created by the Muzzone Dam on the Coghinas River in the province of Olbia-Tempio, with a height of 652 m and a maximum power of 260 MW, as the top-ranking option.