Carbon Cost Comparison: Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs)

by | Oct 21, 2024

Using Green Hydrogen Across Their Life Cycle

With the drive to reduce carbon emissions, two key technologies stand out for the future of transportation: Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs) powered by green hydrogen. Green hydrogen as produced by Haush through electrolysis using renewable energy sources, making it a clean fuel with near-zero emissions.

Haush wanted to make this comparison that evaluates the carbon footprint of BEVs and FCEVs across three phases:

  1. Manufacturing Carbon Cost: Emissions from the production of the vehicle, including batteries or fuel cells.
  2. Running Carbon Cost: The emissions from using electricity or green hydrogen over the vehicle’s lifetime.
  3. End-of-Life Carbon Cost: Emissions related to the disposal, recycling, or reuse of vehicle components at the end of their life cycle.

1. Manufacturing Carbon Cost

BEVs:

  • Battery Production: The largest carbon cost in BEV manufacturing comes from the production of  lithium-ion batteries. Extracting and processing raw materials like lithium, cobalt, and nickel is energy intensive. Although efforts are being made to reduce emissions during production, this remains the most significant carbon contributor particularly since most is mined in Australia and South America and the carbon cost in extraction and transport is also high.
  • Estimated Emissions: Producing a BEV with a 60-kWh battery emits around 8-12 tonnes of CO₂. The battery alone accounts for 40-50% of the total production emissions.
    • Key Points:
      • Battery manufacturing has a high carbon footprint, but this can be improved with cleaner production methods.
      • Emissions depend on the energy source used for battery manufacturing, with renewable energy reducing the carbon impact.

FCEVs (Using Green Hydrogen):

  • Fuel Cell Production: Fuel cells rely on materials like platinum, which is energy-intensive to mine and process. However, the carbon footprint of manufacturing fuel cells is generally lower than that of large BEV batteries. Additionally, advances in reducing platinum usage are making FCEV manufacturing less carbon intensive. South Africa accounts for the majority of the output of Platinum. Other large platinum mines are in the Chocó Department of Colombia, the Ural Mountains in Russia and Ontario in Canada
  • Hydrogen Storage Tank: FCEVs require high-pressure hydrogen tanks, made from carbon-fiber composites, which add to the manufacturing emissions.
  • Estimated Emissions: The carbon cost of producing an FCEV is around 7-10 tonnes of CO₂, slightly lower than that of a BEV due to the smaller battery (or none, depending on the model) and more efficient use of materials.
    • Key Points:
      • FCEVs have a lower carbon footprint during manufacturing than BEVs, primarily because fuel cells require fewer raw materials like lithium and cobalt.
      • Hydrogen storage tanks do contribute some additional emissions.

2. Running Carbon Cost (Over its Lifetime)

BEVs:

  • Electricity Source: BEVs’ running carbon cost depends on the electricity grid’s energy mix. In countries like the UK, where renewable energy sources are increasingly used, the emissions per kWh of electricity continue to fall.
    • For example, the UK grid emits around 230 g CO₂/kWh today but is expected to become even cleaner over time.
    • Energy Efficiency: BEVs are highly efficient, consuming around 18-20 kWh per 100 km.
  • Estimated Running Carbon Cost:
    • Over a lifetime of 200,000 km, a BEV would consume approximately 36,000kWh
      • Assuming the UK’s current grid, this would result in around 8.3 tonnes of CO₂ emissions, although future improvements in renewable energy could bring this down to 2-4 tonnes.

FCEVs (Using Green Hydrogen):

  • Green Hydrogen: Powered by hydrogen produced using renewable electricity through electrolysis, green hydrogen is nearly carbon-free during use. The key to making FCEVs a zero-emission technology is using green hydrogen exclusively.
  • Hydrogen Consumption: FCEVs are less energy-efficient than BEVs, typically consuming 1 kg of hydrogen per 100 km. Over a lifetime of 200,000 km, an FCEV would require 2,000 kg of hydrogen.
  • Estimated Running Carbon Cost:
    • Green hydrogen production emits close to 0 tonnes of CO₂, assuming that the electricity used for electrolysis comes entirely from renewable sources.
    • Therefore, an FCEV using green hydrogen would have a 0 tonnes of CO₂ running cost over its entire life cycle.

3. End-of-Life Carbon Cost

BEVs:

  • Battery Recycling: Recycling BEV batteries is a complex process, as it involves recovering materials like lithium, cobalt, and nickel. While advancements are being made in battery recycling technologies, improper disposal of batteries can lead to environmental harm.
  • Estimated End-of-Life Carbon Cost: Recycling a BEV battery can emit around 0.5-1 tonne of CO₂, depending on the recycling technology used and the energy source.

FCEVs:

  • Fuel Cell Recycling: The fuel cell contains valuable materials like platinum, which are easier to recover and recycle than the metals in BEV batteries. This makes FCEVs less complex and potentially less environmentally harmful at the end of life.
  • Hydrogen Tank Disposal: The disposal or recycling of carbon-fiber hydrogen tanks remains challenging, though innovations are being developed to recycle the composite materials.
  • Estimated End-of-Life Carbon Cost: The recycling of an FCEV fuel cell and hydrogen tank is expected to result in around 0.2-0.5 tonnes of CO₂.

Total Carbon Cost Comparison (Using Green Hydrogen)

Lifecycle Phase BEV (tonnes of CO₂) FCEV (tonnes of CO₂, Green Hydrogen)
Manufacturing 8-12 7-10
Running (Green Hydrogen) 8.3 (UK grid) 0
End-of-Life 0.5-1 0.2-0.5
Total 16.8-21.3 7.2-10.5

We therefore estimate that vehicles that are powered by Hydrogen and Fuel cells has less than 50% of the carbon emission in a lifetime compared to Battery electric Vehicles.

Summary of Findings (Green Hydrogen Only)

  1. Manufacturing:
    1. BEVs have a higher carbon footprint during production due to the energy-intensive process of manufacturing large lithium-ion batteries.
    1. FCEVs have lower manufacturing emissions, particularly due to less reliance on rare materials and smaller or non-existent batteries. However, hydrogen storage tanks do add some emissions.
  2. Running Costs:
    1. BEVs still generate some emissions during use, especially if powered by electricity from a grid mix that includes fossil fuels. As the grid becomes greener, this carbon cost will decline, but currently, it remains around 8.3 tonnes of CO₂ for a BEV over 200,000 km.
    1. FCEVs, when using green hydrogen, have a zero-running cost in terms of carbon emissions. Green hydrogen, produced via electrolysis with renewable energy, is carbon-neutral during use, making FCEVs a true zero-emission technology during operation.
  3. End-of-Life:
    1. Both BEVs and FCEVs have end-of-life carbon costs, but FCEVs tend to have a lower carbon impact due to easier fuel cell recycling processes and less complex disposal of components.

When comparing the total carbon cost across the life cycle, FCEVs powered by green hydrogen as produced by Haush, have the potential to offer a lower overall carbon footprint than BEVs, especially in regions where renewable energy is readily available for hydrogen production.

While BEVs remain more efficient in terms of energy use, their manufacturing and end-of-life carbon costs are higher due to the energy-intensive process of battery production and recycling. Additionally, until electricity grids become fully decarbonised, BEVs will still emit some carbon during operation.

In contrast, FCEVs, when running exclusively on green hydrogen, offer near-zero emissions during their use phase, and their lower manufacturing and recycling impacts make them a strong contender for a low-carbon future. However, the scalability of green hydrogen production is crucial for realising this potential and that’s why Haush will have in 2027 around 300MW of Green Hydrogen in production in the UK.

Both technologies have vital roles to play in the transition to a carbon-neutral transportation system, but FCEVs, especially with green hydrogen, may hold the advantage in applications requiring long ranges, fast refuelling, limited access to electric charging infrastructure, compared to Hydrogen at the petrol station and therefore a lower overall carbon footprints.

Haush CO2 Savings

Haush with its 300 MW of electrolysers can produce 144,000 kg of hydrogen per day.

This could supply approximately 288,000 FCEVs, 4,000 HGVs, or 38,400 Cars (Commercial vans) each day, depending on the mix of vehicle types.

Between 2027 and 2030, this amount of green hydrogen could play a significant role in supporting the growing fleets of hydrogen-powered vehicles, depending on the adoption rate of FCEVs, HGVs, and commercial hydrogen vehicles.

By switching to hydrogen-powered vehicles, a 300 MW electrolyser could save approximately 7.12 million tonnes of CO₂ between 2027 and 2030, depending on the mix of FCEVs, HGVs, and commercial vehicles.

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