Dynamic evaluation of the electrical primary energy factor for building energy performance: Insights from 2022 Italian data

The primary energy factor (PEF) represents a fundamental concept for converting a final energy carrier into primary energy. Among its many areas of application, building industry is of particular interest, since primary energy demand is a representative and widespread indicator for evaluating a building's whole energy performance. This paper starts by exploring the critical issues related to the use of PEF, which is often evaluated through outdated, static values. Through the application of one of the methods of the UNI EN 17423:2021 standard, the hourly trend of the primary energy factor for the electric carrier in Italy during the year 2022 was evaluated. Results show the strong dynamicity of the PEF and the existing relationships between its renewable and non-renewable shares, which are strongly influenced by production, import and export strategies. The obtained PEFs were applied to a case study of a residential building, evaluating the primary energy needs under different final energy conversion scenarios. This work highlights the need for an update of the PEF to dynamic values consistent with the energy context of a country to facilitate the energy transition, as well as to reduce the supply and demand mismatch, and reward the use of renewable energy.