Hydrogen Vehicles and the Carbon Footprint of the Energy Supply Chain

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By Aurélien Schuller, Manager, Co-Head of the Mobility Practice

European automakers see the European target of 95 g CO2/km for car tailpipe emissions in 2020–2021 drawing nearer(a goal that, if not met, could result in severe penalties—as we discussed in the previous version of this letter). TheThe news is therefore full of announcements regarding the electrification of the model lineups. Whether they are plug-in hybrids or 100% electric, electrified vehicles do indeed have the clear advantage of low exhaust emissions under European regulations. They even benefit, in part, from bonus coefficients in the weighted calculation of a manufacturer’s average CO2 emissions. We have already had the opportunity in these pages to mention the fact that This system fails to account for a significant portion of the vehicle's life-cycle emissions: the discrepancy between certified fuel economy and real-world fuel economy; upstream fuel or electricity production; the environmental impact of manufacturing the vehicle and its battery… These are just a few of the pitfalls of a methodology based solely on vehicle exhaust emissions.

Commercial vehicles are part of this broader shift toward electric vehicles because they also have a goal of reducing CO2 emissions. PSA’s recent announcement [1] on this topic provides an opportunity to highlight one form of electrification in particular: hydrogen-powered vehicles. The manufacturer announced that Commercial vehicles would be the priority in terms of H2 development across its lineup, and that The first utility vehicles could be delivered in 2021 or even earlier. Hydrogen vehicles are electric in the sense that H2 fuel is used to power an electric motor, and they are also electric in the sense that the hydrogen used can be produced from electricity through water electrolysis. For those who place particular importance on the life-cycle carbon footprint, Emissions associated with the energy-intensive production of hydrogen are difficult to quantify.

In fact, while it is desirable toavoid the use of hydrogen produced from fossil fuels as is currently the case for industrial needs (primarily through methane steam reforming), Electrolytic production is also not good news for the climate in the case of certain high-carbon electricity mixes. And in cases where the electricity mix is low-carbon, the trade-off is a close one between an all-electric vehicle—whose carbon footprint is weighed down by the carbon debt associated with battery manufacturing—and an H2 vehicle, which consumes more electricity across the entire energy chain. While it would be wrong to let the complexity of the issue prevent us from undertaking the necessary reduction of transportation emissions, let us hope that the question of upstream energy will be thoroughly addressed as various types of electrified vehicles are developed.

Sources: [1] JournalAuto.com