Alternative to ICE Powertrain: Battery Electric Vehicle versus Fuel Cells

In an effort to mitigate environmental concerns, the world is witnessing a gradual, but promising transition from Internal Combustion Engine (ICE) vehicles towards Battery Electric Vehicles (BEVs). However, inadequate driving range due to lower energy density of batteries for a given purchase cost of the Electric Vehicles (EVs), and long charging time are among the main barriers to EV adoption, especially, in the medium and heavy vehicle segments.

In the search for an alternative source of fuel, governments are recognising hydrogen’s ability to decarbonize sectors that are difficult to abate – personal or collective transportation, freight logistics, etc. Hydrogen is also gaining traction in industries like automotive, chemical, oil and gas, and heating, where it is being viewed as a viable alternative for achieving long-term sustainability.

Another substitute for ICEs is Fuel Cell Electric Vehicles (FCEVs), which can help reduce emissions and petroleum use from on-road vehicles. FCEVs run on compressed liquid hydrogen. The reaction between hydrogen and air inside the fuel cell stack powers an electric motor that drives the wheels. Similar to BEVs, they are noiseless and produce zero emissions, apart from having a tank that can be refilled in a few minutes, just like ICE vehicles. In FCEVs, where chemical energy is converted into electric power in the fuel cell and hydrogen fuel is stored in a tank, energy density, and thus the range, is less of a concern. The use of an inefficient energy conversion device is mitigated by the liquid fuel tank’s extremely high energy density. An FCEV can deliver average power at significantly higher efficiencies than a combustion engine. However, to deliver peak power, the fuel cell must be large, which makes it costly.

Hydrogen as a Fuel

Hydrogen is one of the cleanest fuels, with zero vehicular emissions. Depending on the energy source of the production process, hydrogen can be categorized as blue, grey, and green. For instance, blue hydrogen is produced when natural gas is split into hydrogen and carbon dioxide (CO2), but the latter is first captured and then stored to mitigate the environmental impacts on earth. Grey hydrogen is produced from fossil fuels without carbon capture and storage. Green hydrogen is produced by splitting water through electrolysis, where the hydrogen can be used and the oxygen can be let open to the atmosphere with no negative impact. The cost of green, blue, and grey hydrogen is in the range of 2.5 – 6 USD/kg H2, 1.5 – 4 USD/kg H2, and 1 - 2.5 USD/kg H2, respectively. The large-scale production and distribution of hydrogen along with low-cost renewable energy sources, lowcost electrolyzer and supply chain optimization can reduce the cost of green hydrogen significantly. It is estimated that green hydrogen can be produced in the range of USD 0.8/kg – USD 1.6/kg in most of the countries before 2050.

Hydrogen as a fuel could play a crucial role in a low-carbon future along with electricity as a fuel, leading to diminished dependence on fossil fuels. Owing to its high energy density as compared to other fuels, it produces more energy at a lesser weight, which explains its viability for heavy vehicles built for long hauls. When compared to BEVs and ICEs, the refuelling time required for hydrogen is also low, although the former two are way ahead of hydrogen in terms of maturity and availability of infrastructure.

Drivetrain Comparison: ICE vs FCEV vs BEV

The current environmental concerns warrant that India starts to embrace alternative fuel technologies, besides BEVs. The general perception of FCEVs is unfavorable, to say the least, with the idea of a hydrogen-based economy continually being misunderstood and tagged as unfeasible. FCEVs find their high costs as one of their main challenges today, courtesy to the high cost of hydrogen production, fuel-cell stacks and establishment of hydrogen fuel stations. If this technology is developed and finds wider acceptance, costs can be reduced. However, India, at present, does not have even a single hydrogen fuel station. Nevertheless, there is evidence of a slow acceptance of hydrogen as an alternative fuel with Tata Motors collaborating with the Indian Space Research Organization (ISRO) and Indian Oil (IOCL) to launch a hydrogen fuel cell bus. Moreover, Hyundai, which has already launched the Kona Electric in India, also plans to launch its first fuel cell SUV in India by 2021 with the necessary infrastructure being built in and around the Delhi-NCR area. Globally, countries such as Japan, China, the United States of America, Korea and some European countries have started to warm up to the idea of a hydrogen-based society while simultaneously making continuous investments towards cleaner production technology.

A comprehensive comparison between ICEs, BEVs, and FCEVs showed that in terms of capital costs, safety, range and refueling speed, ICEs are way ahead of the other two alternatives. The parameters it falls behind in are fuel cost and the extent of emissions produced. However, FCEVs have the potential to overcome high-cost barriers in the future through scaled-up manufacturing, least emissions and assured safety.

Conclusion

BEVs and FCEVs are two “clean” automotive technologies having the potential to be integrated with renewable energy sources. BEVs have lower fuel consumption and high energy efficiency, given their overall weight - which isn’t too high - making them ideal for traveling short distances. FCEVs can store a greater amount of energy in relation to their weight, besides having a much shorter refilling time, thus making them an appropriate choice for long journeys. However, at present, the EV ecosystem is more developed, and talks about a hydrogen economy are still in their infancy. Nonetheless, FCEVs are indeed the future of a more environment-friendly way out for urban transport, especially the long-haul heavy vehicles, which is why they shouldn’t be ruled out as an alternative. The future of mobility lies in the coexistence of alternative fuel technologies, which translates into a future where BEVs and FCEVs are not placed against each other but play a complementary role to address environmental concerns together.

- Dr. Parveen Kumar, Senior Manager, WRI India