Hydrogen Fuel-Cell Vehicles (Part 1: The Scientific Principles)

For anyone who was deterred by the detrimental effects of lithium-ion batteries in electric vehicles (EVs), hydrogen fuel-cell vehicles (FCVs) present another plausible alternative to the conventional internal combustion engine vehicles (ICEVs). Just this morning, Singapore’s state-owned newspaper published an article on local firm Spectronik’s plans of producing FCVs, suggesting that EVs may not be the only route forward in Singapore’s drive towards sustainable road transport. Before getting ahead of ourselves, let us watch 2 quick videos to understand the technical principles behind FCV operation and hydrogen production!

To verify if FCVs are truly beneficial for the environment, we examine their life-cycle assessments (LCA) against other vehicle types. A recent study conducted in China demonstrates that materialization of these benefits depends on how the hydrogen is sourced. While FCVs under most hydrogen generation channels examined compared favourably against both ICEVs and EVs in reducing greenhouse gas (GHG) emissions, the opposite holds true when electricity from China’s State Grid is used to power electrolysis for hydrogen production. These findings mirror those from an earlier South Korea study, though the latter’s assertions of lower GHG emissions from FCVs cannot be hastily generalized to other geographies, due to differences in hydrogen production methods.

Source: Yang et al., 2020

Switching from ICEVs to FCVs can also improve air quality by reducing emissions of several common pollutants, such as volatile organic compounds (VOCs) and carbon monoxide (CO). Once again, using China’s grid electricity to produce hydrogen proves counterproductive due to its significant volumes of air pollutants emitted during upstream processes. This highlights the importance of transitioning away from fossil-fuels in favour of renewable energy, as progress in other environmental indicators are bolstered by a ‘green’ electricity generation mix. Using continental Europe’s electricity mix as an input suggests that FCVs not only have greater potential in mitigating global warming than EVs and methanol vehicles, but also score better in ozone depletion and human toxicity metrics.

Source: Wang et al., 2020

From the angle of environmental sustainability, there certainly exists scientific justifications in supporting FCV development. My next article will be assessing its present-day situation and upcoming prospects.