There has been a growing argument over Hydrogen’s place in the world’s future economies. Some assume it is a silver bullet to everything emissions, and others believe it makes more sense to Electrify everything and avoid investing in Hydrogen altogether.
To go forward we need to be realistic about the place of Hydrogen in the Net-zero economy and which sectors it will be able to genuinely decarbonise.
In 2018, 51% of the Hydrogen on the market was used as a feedstock to make Ammonia (which is used in making fertilizers, among other uses), and 42% was used to reduce the sulfur content from diesel in the Oil Refining industry.
The worrying part is that 95% of the Hydrogen consumed comes from reforming Natural Gas, a fossil fuel.
Many Hydrogen supporters believe that it should replace fossil fuels in every single field, from transport to residential heating. Let’s break it down and see where Hydrogen could realistically contribute to achieving Net Zero over the upcoming number of articles.
Land Shipping
Hydrogen has been called upon to replace fossil fuels in the transport sector since the 70s oil crisis and after every oil crisis. The first Hydrogen tractor that utilises fuel cells was built in 1959.
Vehicles powered by Hydrogen use Fuel Cells that are fed by pressurized Hydrogen fuel and oxygen from the air to produce electricity to power the vehicle. Hydrogen vehicles are arguably lighter than EVs and take much less time to refuel.
Energy Density
Now let’s talk about Energy density. Energy Density per kg means how much energy (watt-hour in our case) is stored in each kg of something.
According to the USA DoE, commercially available EV batteries had a density of 450 Watt-hour/kg in 2020.
Now the Hydrogen tank capacity in the Hydrogen-powered Toyota Mirai is 122 litres (5.6 kg) divided between two tanks with the gas compressed at 700 bar (700 times atmospheric pressure) and a density of 1,990 Watt-hour per kilogram, assuming an 87.5 kg tank.
Diesel has a lower energy density than Hydrogen, however, a tank of diesel holds more kilograms of Diesel.
Hydrogen’s energy density is much better than the current generation of commercially available EV batteries. There are batteries with higher densities, such as Amprius’s Lithium-ion battery, shown above, with 450 Watt-hour/kg battery density that are currently being used to power satellites, which means that they are not affordable enough yet for mainstream EV vehicles.
There are promising advances in the Lithium battery sphere. Lithium-Sulphur batteries have a theoretical density of 2,500 Wh/kg, which is 66% higher than the current Hydrogen tanks. However, Lithium-Sulphur batteries are still being researched and they have their own limitations that require more R&D before they become market ready.
Heavy Trucks
By increasing the size of the vehicle and the weight it needs to transport we will need bigger batteries. This brings us to long-haul semi-trucks (i.e. Category 8). Those trucks must carry much heavier loads and be continuously on the road for much longer hours than smaller trucks and vehicles.
For this article, 3 different Electric Semi Trucks will be used as an example:
- BYD’s 8TT,
- Freightliner’s eCascadia,
- Volvo’s VNR
The three models will be compared to the Hydrogen version of the Hyundai XCIENT
The Tesla Semi was going to be included, however, no information was released about the curb weight of the truck.
It is good to note though that the only reason Electric Trucks are allowed to carry more than Hydrogen Trucks is due to local regulations. In the USA Electric Trucks are allowed to be up to 0.9 tonnes heavier than diesel trucks, while in the EU the limit is extended by 2 tonnes.
From the tables, it is clear that Hydrogen Trucks are a much better option, IF, hydrogen refuelling stations are readily available on logistical routes. Hydrogen Trucks can refuel much faster than their electric counterparts and carry more.
However, the biggest issue stopping the Hydrogen Vehicles (FCV) market from expanding is the source of the Hydrogen. The majority of Hydrogen we have on the market comes from Fossil Fuels and the main point of using FCV is to move away from Fossil Fuels, so the Hydrogen used has to be green and produced via renewable sources, such as solar & wind.
This brings us to where EVs are better. Efficiency. It has been demonstrated by Volkswagen recently that, in the case of EVs, 76% of the electricity produced by the renewable energy source is used by the vehicle.
While for FCVs the path from the field to the vehicle is much longer and cannibalizes more from the electricity generated, as shown below.
With Green Hydrogen, the power produced from the renewable energy source will be fed into an electrolyser, and then the produced hydrogen will then be compressed for transmission to the fueling station. This direction, after taking into account the energy loss inside of the vehicle itself, will result in only 30% of the energy produced by the renewable source being used by the vehicle.
Cost of Fuel
Currently, we can guess how much the cost of recharging a semi-truck will be, but the situation is different for Hydrogen. The only reliable pricing we have for Hydrogen is from the cost required to extract it from Natural Gas through SMR (Grey Hydrogen).
The IEA mentioned in their 2021 report that the Levelized Cost of Green Hydrogen per kg in G20 countries is currently between US$3/kg & US$8/kg. Please note, that the LCOH above does not include the seller’s markup.
The cost of electricity in the United States ranged between $0.118/kWh to $0.408/kWh in 2022, while the cost of Diesel fuel for a semi-truck of an average consumption of 8 Miles Per Gallon in:
- The USA was between $0.21/km and $0.28/km
- Mainland EU was between $0.33/km and $0.66/km.
The graph clearly shows that the lower range of cost of Hydrogen is barely cheaper when compared to diesel in the USA, and it is slightly cheaper than the cost of Diesel in the EU, or BYD semi-trucks.
This is it, let’s electrify everything, right? Not necessarily.
EV supporters believe that the issue with the size and cost of EV batteries and the lack of fast chargers will be solved in the near future and it should not be an issue for EV adoption at the moment. However, the same argument could be made for the Green Hydrogen required or the FCVs.
Furthermore, there is no guarantee that the electrons that will flow into the EV batteries will be 100% electric. Power mix differs from one region, state, & country to another depending on their individual energy policies.
Another debate is being made about utilising renewable energy to produce Hydrogen in the first place. Many are calling it useless to use a viable source of energy to produce an energy vector like hydrogen for it to do the same thing the primary energy vector could do.
Now, this brings us to the next article. Hydrogen Vs Electricity in Heavy Industries.