Fuel Cell Electric Vehicles

Oct 1

We’ve received several inquiries recently about the potential of Fuel Cell EVs (FCEVs), also known as hydrogen vehicles. These vehicles generally have a small battery, just like regular EVs (Battery EVs or BEVs), and a fuel cell that converts hydrogen into electricity stored in the battery. The remainder of the vehicle is similar to a BEV. This technology offers the advantage of quick fill-ups - it’s not too different from filling a gas or diesel vehicle. Another benefit is that there can be a weight advantage in long-range heavy transportation.

So, how does it compare to a BEV?

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A CleanTechnica article from June 2020 offers a comprehensive answer and explanation. The gist:

The BEV is a more efficient system when you consider the end-to-end process. BEVs are over 70% efficient.
FCEVs are 22% efficient

Check out this Car Buzz comparison between popular Teslas and the Toyota Mirai for a better sense of the differences.

There are better applications for green hydrogen, e.g., industrial processes, long-range heavy transport (land, air, and sea).

The color of hydrogen matters a lot!

Hydrogen is the fuel of the FCEV, and the hydrogen that matters is green (produced through electrolysis using renewable energy). Electrolysis is a process that uses a significant amount of energy. Unfortunately, over 99% of hydrogen made around the globe today is grey (CO2 emitting) or blue (CO2-sequestered). Blue and grey hydrogen are produced from natural gas (methane) or coal through energy-intensive processes like steam reformation, gasification, and pyrolysis. You read that right - most hydrogen is produced from fossil fuel and the production process releases emissions! Read more here and here.

For hydrogen to make environmental sense, it must be produced using truly renewable energy sources. To rely on any other form of hydrogen further contributes to our dependence on fossil fuels and planet-warming emissions.

What about FCEV fueling?

Fueling an FCEV is fast - it takes about 5 minutes to top off. Here’s a video of the Toyota Mirai being filled at a fueling station. FCEV fueling is, clearly, an advantage. The fastest reported EV charging station will take about 15 minutes to change a battery that is depleted.

In reality, EVs are generally not drained completely before they are charged. Additionally, many EV owners have the opportunity to charge at home in a series of top-offs, not unlike how a smartphone is charged.

An important consideration is fueling infrastructure - the classic ‘chicken and egg’ dilemma that BEVs faced in the past, i.e., fueling infrastructure will be required for people to be comfortable owning an FCEV like the Mirai. However, commercial hydrogen fueling stations are expensive - they cost over $1,000,000 to construct - so it will take a lot of investment to create an adequate fueling system. (DC Fast Chargers are around $120,000). Therefore, the hydrogen fueling station gap is a much stronger barrier to the adoption of cars like the Mirai.

Do hydrogen vehicles make sense for Hawaii?

Yes and No.

Using hydrogen in fuel cells or in internal combustion engines may make sense for heavy long-range transport, e.g., tractor-trailers, marine transport, and trans-Pacific aviation. In these situations, the long-range travel benefit outweighs the disadvantages. However, much more progress must be made in the generation of affordable green hydrogen in order for the economics to work out. Additional investment in renewables, particularly geothermal, may allow for abundant affordable green hydrogen.

For cars and other ground vehicles, the BEV format is optimal for the following reasons:

Battery EVs are many times more efficient. We cannot afford to waste precious energy. (We’re better off using extra energy to reduce electricity costs for our households.)
EV charging infrastructure is already readily available in homes and in the public domain. Owners with home charging now rarely need to use public charging stations as most EVs now come with 200+ miles for a full charge. Many affordable EVs are capable of over 300 miles of driving range. There is also great momentum to dramatically expand public charging.
Affordable long-range EVs are now available across many makes and models. Trucks are also coming!
Battery and charging technology is reaching a point where rapid public EV charging is feasible. Charging at a rate of 120 miles of range in 6 minutes is coming with ABB’s Terra 360.