TRNTY Associate Q&A: Hydrogen Powertrain Opportunities
In a recent interview with one of our TRNTY hydrogen powertrain experts, we discussed why large automotive groups with diverse product portfolios, need to pay attention to the developments in hydrogen fuel cell technology.
The automotive sector is heavily focussed and invested in powertrain electrification. It is key to achieving necessary reductions in CO2 emissions and to demonstrate technology leadership. Hydrogen fuel cell technology is often considered to be a more expensive, less mature and less energy efficient contender.
Yet according to TRNTY Associate Freddie Mehta, H2 a technology which key industry players cannot afford to dismiss.
In this interview with TRNTY, Freddie talks about the relevance of proton exchange membrane fuel cell technology for the automotive industry from the aspects of:
- The fragility of lithium-ion battery supply chain
- Energy Efficiency vs Density
- Heavy-duty applications
Freddie, what are the main concerns around the lithium-ion battery supply chain?
Accessibility of lithium is a major consideration, as well as the accessibility of cobalt.
How is lithium currently sourced?
Lithium is available as water-based or rock-based.
Water-based lithium is mainly sourced from the Bolivian Salt Flats and the neighbouring region, encompassing Argentina, Bolivia and Chile, called the Lithium Triangle. There is extensive lithium buried under layers of other salts that need to be dissolved. Then that lithium solution needs to be spread out over a large field and the water naturally evaporated. Resulting lithium carbonate is also called ‘white gold’.
As the demand for lithium has increased exponentially, people are looking into sources of energy that can evaporate the water while keeping the carbon equation more sustainable. Traditional sources of energy do not yield a positive impact on CO2 emissions. Consideration needs to be paid also to the water usage, as nowadays freshwater is a quite scarce commodity.
Hard rock lithium is almost exclusively available in Australia. Rock-form lithium needs to be pulverised and dissolved in a more acidic solution than water. It is, therefore, more energy-intensive to source and the process is even less environmentally friendly. This means hard rock lithium is quite ’dirty’ source of energy in the sense of extraction, transport and manufacture.
What are the main concerns around sourcing cobalt?
Cobalt is another mineral which is currently critical to the quality of the lithium-ion battery, improving its energy density. Cobalt is not widely available, except in the Democratic Republic of Congo, which contains 70-75% of the world’s resources.
Unfortunately, the country has a poor human rights record and imposing good processes and practices are challenging, due to overall government structure and disruptions in the local situation could impact the global supply chain.
What does that mean for overall lithium-ion battery supply?
This means we cannot look at the goal as ‘replacing every ICE with BEV’. We need to look at the overall equation of how to reduce CO2 and to ensure the security of supply.
Relocation of certain industrial lithium manufacturing processes would benefit the overall situation because currently lithium salts are shipped almost around the world, before being sent to a cell manufacturer.
We also need to accept the geopolitical risks of relying on a limited set of countries to provide lithium, for example, the dangers of political unrest in key regions or finding significant new rock reserves in a new location.
Understandably, there is a desire in the industry to make batteries cobalt-free, but that will worsen the overall energy density problem. That will further limit the use of lithium-ion for heavy-duty and off-road applications, not to mention aviation, which is even more weight sensitive.
Why energy efficiency should NOT be the key consideration when assessing power train strategies.
Any fuel cell system is going to be much less efficient in terms of tank-to-wheel energy-usage. But even though the fuel cell efficiency is less than a third of lithium-ion, hydrogen as fuel storage is also 240 times more energy-dense than lithium-ion.
That scale of magnitude of difference, on top of the supply chain risks, is what makes it clear that one system is not the answer.
We need to consider hydrogen, even if it’s less energy efficient because it’s much more energy-dense and therefore easily viable for heavy-duty applications. If you’re a big-name manufacturer, whose portfolio includes heavy-duty vehicles as well as passenger cars, you need to hedge your overall powertrain strategy with hydrogen fuel cell technology.
Even though fuel cell technology is several years behind in development and adoption of BEVs, unless there is a sudden leap in lithium-ion technology, significantly reducing the use of critical minerals, the fore-mentioned geopolitical and logistical challenges remain.
Which automotive applications are most viable for fuel cell?
Passenger vehicles do not offer an attractive business case due to the competitiveness of battery technology in the sector, and the ever-expanding charging network, reducing range anxiety.
With the current manufacturing cost per kilowatt for proton exchange membrane fuel cell, the applications to consider start with big SUVs, which can be weight sensitive.
The hydrogen tank reduces battery requirement by almost 90%, leaving you with a battery that is 10% of the norm, a proton exchange membrane fuel cell and a 10-15 kg hydrogen tank. This means replacing 300 kg of battery with a 6 kg tank, which is equivalent to 3-4 passengers or additional allowance for cargo for load-carrying vehicles. Hyundai NEXO SUV is a great example, with a fuel tank of 6-7 kg running 400+ miles.
The impact of a 90% reduction in battery size will bring its obvious advantages. Increase in application size further benefits fuel cell business case. Many long-range transport and off-highway applications also find the battery charging pattern unsuitable, unless battery modules can be swapped.
Hydrogen has the benefits in terms of re-fuel, as its mimics much closely an ICE vehicle. It only takes 5-minutes to refill a hydrogen tank. Even the fastest EV supercharger will not take less than 25 minutes, due to the nature of cell chemistry. This 20 min difference has a huge impact on behaviour. Imagine stopping at your local petrol station and having to wait for almost half an hour for fuelling, without taking into consideration queuing, paying etc.
When building up hydrogen fuelling system, a lot of the existing industrial pipe infrastructure can be used, providing the end location can have its own purification process. This eases adoption.
It will be interesting to see how the all-electric Tesla semi stands up to the Nikola hydrogen fuel-cell truck. Those two offers will be very different and their load-carrying capacities will be exponentially different, because of the use of massive lithium-ion batteries in Tesla’s case.
Of course, safety concerns need to be evaluated, especially for off-road applications, such as construction and off-highway. FMEA studies suggest hydrogen and conventional fuel carry roughly the same level of risks, as, in the case of a hydrogen explosion, the energy is dissipated, which is worse in some situations and better in others. We also know lithium-ion batteries can burn for 15 days and road rescue services apply different costs and prices for BEVs. We have to distinguish perception from reality, while also acknowledging that for the less mature fuel cell technology, the safety learning curve will be deeper.
What is your key message to OEMs?
The overall message is to be open to fuel cell technology. It is probably of less significance to OEMs that specialise in passenger vehicles, but much more relevant to bigger groups, like Hyundai or HMC, that make heavy-duty vehicles as well as passenger vehicles. Hedge your technology and adopt hydrogen as a more viable solution for heavy-duty applications and focus on electrification for the light-duty and passenger vehicles. The lithium-ion supply chain is fragile and fraught with ethical dilemmas and therefore needs a competitive contender.
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