Time-evolution and forecasting of environmental and energy performance of electricity production system at national and at bidding zone level

The electricity generation system has faced exceptional change lately because of several aspects: the electrification of heating and transport sectors, the spread of distributed energy generation, and the increase of renewable share in the electricity production mix. All these factors have contributed to exacerbate the variability of power system operation. This work aims to present hourly data analysis of the electricity production (from fossil fuels and renewables) at the country level (Italy) and at the bidding zone level in the period 2015–2019. Based on different time-resolution, several datasets have been examined and a reproducible method has been defined to overcome the temporal resolution misalignment. Subsequently, the data has been used to define and calculate the time-dependent energy efficiency and environmental indicators for the electricity system with an hourly timestep both for Italy and related bidding zones. The results have demonstrated that these parameters are extremely variable year by year and hour by hour both at the national and bidding zones level. For example, one of the analysed energy efficiency indicators referred to Italy ranges from 0.4 in the hours in which the renewable share is lower than 10% to 1.8 when the renewable share reaches 80%. At the bidding zone level, the electric efficiency indicators, and carbon dioxide emission factor for electricity show a pattern depending on the specific electricity production mix in each zone evidencing a great difference compared to outcomes related to the whole of Italy. The findings of this work evidence the need of accurate knowledge of these operational indexes in the evaluation of electric-driven energy conversion systems performance, energy planning, and in the improvements of electricity market efficiency.