Hydrogen Fuel Cell Hybrid Electric Vehicles: the Impact of Commercial Vehicle Fleets on the Penetration of Renewable Energy Sources

The transport sector is one of the most significant contributors to greenhouse gas (GHG) emissions, with the road segment accounting for large part of the emissions and requiring immediate action to address the increasing issues of climate change. To this aim, the international community is promoting technological alternatives to fossil fuel-based powertrains, thus favoring the increase in electric vehicle (EVs) penetration. However, to be sustainable the electrification of mobility requires a large share of energy produced by renewable sources to support the decarbonization process. The simultaneous increase in volatility for both the energy demand (due to EVs diffusion) and production (due to the Renewable Energy Sources RES growth), has a significant impact on the reliability of the electricity grid infrastructure. The growth of RES penetration brings an energy production increase that may not synchronized with the demand evolution, possibly leading to a grid imbalance. To this aim, the storing potential of green hydrogen, produced from RES during energy surplus periods, could allow better exploitation of the rising installed RES capacity. The proposed study aims to analyze the benefits that can arise from introducing Fuel Cell Hybrid Electric Vehicles (FCHEVs) in a commercial electric fleet in terms of environmental and grid resilience perspectives. FCHEVs are electric vehicles propelled by a hybrid powertrain, coupling electric battery packs and a fuel cell stack as energy sources; here, hydrogen is used as an energy vector stored in high-pressurized tanks. Starting from a reference scenario of a fleet composed of 10 EVs, the number of FCHEVs is progressively increased to assess their impact on the fleet performance. A set of mission scenarios for the commercial vehicles is obtained through the Markov Chain method, starting from accurate GPS data. These different scenarios are used in a numerical model to optimally plan the fleet scheduling and their configuration in terms of vehicles associated with specific missions. Results show a reduction of up to 57 % in grid fluctuations (estimated through its standard deviation) and a decrease from 77 % to 82 % in CO2 emissions concerning traditional vehicles increasing the FCHEV penetration considering the current Italian energy scenario.