Hourly energy demand impacts of battery electric vehicle adoption in Italy: A grid simulation and policy analysis

• Hourly BEV demand simulation reveals critical grid stress time windows. • 7 million BEVs raise daily demand by 40 % and peak load to 53 GW. • Thermal power emits up to 112,000 tons CO 2 /day in high-BEV scenario. • Existing 5 GWh storage offsets only 20 % of peak demand. • Doubling solar and tripling storage cuts BEV emissions by 35 %. • Time-of-use tariffs shift charging loads and improve grid stability. The growing adoption of Battery Electric Vehicles (BEVs) poses significant challenges to electricity grids, especially in countries aiming for rapid decarbonization. This study evaluates the hourly impact of BEV integration on Italy’s energy system using a Python-based simulation model. Two scenarios are analyzed for 2024: (1) 3.5 million BEVs and (2) 7 million BEVs. The model incorporates hourly charging profiles for household and highway fast-charging, Italy’s renewable energy mix (solar, wind, hydro, bioenergy), and a 5 GWh battery energy storage system. Results show that Scenario 1 increases daily electricity demand by 19 % (to 1.1 TWh), with peak loads of 47–49 GW, requiring 152 GWh of thermal generation and emitting 76,000 tons of CO 2 daily. Scenario 2 raises demand by 40 % (to 1.25 TWh), with peak loads of 50–53 GW, 224 GWh of thermal generation, and 112,000 tons of CO 2 emissions. Existing storage mitigates 20 % of peak load but is insufficient for Scenario 2’s 15 GW shortfall. Key demand spikes occur at 01:00 and 11:00–18:00, coinciding with home and highway charging. Policy strategies such as time-of-use tariffs, expanding storage to 15 GWh, and doubling solar capacity could reduce emissions by up to 35 % and supply 80 % of BEV charging needs during daylight hours. This hourly-resolution analysis offers critical insights for grid planning and supports the EU’s Fit for 55 targets.