The “APE – Energy Notes” series continues with a new issue focused on the adequacy of the power system—a key concept for ensuring energy supply security in Italy and across Europe. Matteo Baù (together with the contribution of Federica Davò) guides us through definitions, methodologies, and evaluation scenarios, offering a technical and regulatory overview to understand current and future challenges.

The analysis begins with the definition of adequacy according to ENTSO-E and Terna: the ability of the power system to meet demand at all times, even under extreme weather conditions or unexpected outages. It introduces the Monte Carlo probabilistic simulation method, which models thousands of future scenarios to estimate the risk of energy shortages. Among the key indicators, LOLE (Loss of Load Expectation) is the most widely used; the MASE decree of 28/10/2021 sets the maximum acceptable threshold at 3 hours/year.

The document compares short-term adequacy assessments (ENTSO-E Seasonal Outlooks) with medium- and long-term evaluations (ERAA and Terna’s Adequacy Report), highlighting how Italy is preparing through investments in grid infrastructure, storage systems, and new generation capacity. The 2028 scenario projects 343 TWh of electricity demand, 59 GW of solar and 22 GW of wind capacity, while the 2033 outlook estimates 378 TWh, 90 GW of solar and 32 GW of wind. Storage capacity increases from 13.9 GW in 2028 to 27.4 GW in 2033, with a growing role for utility-scale systems.

Finally, the analysis calls for innovative approaches to manage uncertainty and complexity in the power system, including probabilistic tools and a revision of planning criteria. Adequacy is not just a technical measure—it is a strategic test for the resilience of the country’s energy system.