Tasmania will soon become the first Australian state to install hydrogen fuel pumps. These will allow a driver to fill up a car that runs on a hydrogen fuel cell. Hydrogen vehicles are touted as a clean energy transport option, as the fuel releases no carbon dioxide emissions. However, this government-funded trial in Tasmania is only a small step toward the widespread adoption of hydrogen vehicles. This article will explore the steps needed before this promising technology breaks into the mainstream.
Can you use a hydrogen fuel cell for electric vehicles?
There are vehicles fuelled by hydrogen rather than petrol or electricity. Instead of a battery or motor, such vehicles use a hydrogen fuel cell. Fuel cells are lighter than batteries. They also take less than five minutes to refuel. This involves pumping hydrogen into the tank, much like we do for petrol vehicles.
What is a hydrogen fuel cell?
A hydrogen fuel cell converts hydrogen or other fuels into electricity using an electrochemical reaction between hydrogen gas and oxygen. Apart from electricity, the only other by-products of this reaction are water and heat. Therefore, hydrogen vehicles emit only vapour and heat from the tailpipe.
How does a hydrogen fuel cell work?
A hydrogen fuel cell contains an anode, a cathode and an electrolyte membrane. Hydrogen goes through the anode and oxygen travels through the cathode. The hydrogen splits into electrons and protons once it reaches the anode. Then the protons travel through the electrolyte membrane. At the same time, the electrons move through a circuit. This generates an electric current and excess heat. It is this electric current that powers a hydrogen vehicle. The final process in a cell sees the protons, electrons and oxygen combine at the cathode to produce water molecules. Vehicles then emit this by-product as water vapour via the tailpipe.
Hydrogen fuel cell cars
As of 2022, there are only two hydrogen fuel cell cars available in Australia. Moreover, Toyota and Hyundai only offer these vehicles as large orders of many vehicles or on loan. The sole example of this in Australia is the ACT government’s purchase of 20 hydrogen fuel cell cars for its government fleet. However, Australian manufacturers plan to build hydrogen vehicles. This includes a start-up that has developed a hydrogen fuel cell utility vehicle, while another company is focused on hydrogen truck production.
Cost of hydrogen cars
Unfortunately, hydrogen cars are expensive. This is often the case with a new technology that is not yet widely available. However, technological advancements are bringing down the price of hydrogen vehicles. As this will incentivise an increase in the demand for hydrogen vehicles, Australia has begun to roll out hydrogen refuelling stations. This is an important aspect of the Australian government’s Future Fuels Programme. The programme funds infrastructure to “enable the demonstration and deployment of new zero emissions vehicle technologies”. Such infrastructure includes hydrogen refuelling stations, with the aim to “commercialise hydrogen as a transport fuel”.
Still, a greater issue plagues the technology. That is, where the hydrogen fuel comes from before it reaches a fuel cell. Hydrogen is the most abundant element in the universe. However, it does not occur naturally. One way energy producers can obtain hydrogen is to extract the element from water through electrolysis. When done using renewable energy, the result is ‘green hydrogen’.
This is the only true clean form of hydrogen. But, to date, energy companies have mostly separated hydrogen from fossil fuels. This process releases greenhouse gas emissions. Therefore, if we are to pursue hydrogen vehicles as a clean energy transport option, we need to use green hydrogen as fuel. Unfortunately, the electrolysis process that converts renewable electricity to hydrogen adds to the cost of producing the fuel. Due to this, 95 per cent of global hydrogen production derives from fossil fuel sources.
Hydrogen fuel cell efficiency
Another issue surrounding hydrogen is its efficiency. A fuel cell does have higher efficiency than a combustion engine. The most efficient combustion engines on the market have a fuel efficiency of about 40 per cent. That is, they convert only 40 per cent of the fuel energy into movement. On the other hand, hydrogen fuel cells can convert the chemical energy in hydrogen to electrical energy with an efficiency of more than 60 per cent, according to the US Department of Energy.
However, a hydrogen fuel cell vehicle is not as efficient as an electric vehicle that runs on a lithium-ion battery. This is especially the case if we factor in the loss in energy from first converting electricity from a renewable source to hydrogen. During this electrolysis process, about one-quarter of the electricity is lost. This has led some scientists to suggest that hydrogen cars will never overtake electric vehicles in the race toward clean transport options.
Are hydrogen fuel cells as cost-effective as other forms of energy?
The cost of energy generated by a hydrogen fuel cell is another barrier to the widespread adoption of hydrogen vehicles. Though hydrogen is more efficient than fossil fuels once it is produced, a unit of power from a hydrogen fuel cell is less cost-effective than most other fuel sources. The US Department of Energy notes that the price of a hydrogen fuel cell will have to decline significantly to be competitive on the market.
How expensive is hydrogen fuel cell technology?
As of 2020, fuel cells were still much more expensive than either batteries or petrol. This is partly due to costs associated with manufacturing the cells themselves. However, technological innovations and product improvements have continued to drive down the cost of hydrogen fuel cells. Namely, from 2006 to 2018, the price of a hydrogen fuel cell dropped roughly 60 per cent.
Due to this increased cost-competitiveness, US experts have predicted hydrogen fuel cells will soon replace battery-powered systems in certain types of vehicles. This includes forklifts and long-haul trucks. Other expert predictions from the US suggest that mass-produced hydrogen fuel cell vehicles could be similar to the cost of a hybrid vehicle by 2025. However, even with hydrogen fuel cell technology becoming less expensive, the cost of hydrogen production remains a concern.
Hydrogen production in Australia
In 2020, Darren Miller, CEO of the Australian Renewable Energy Agency (ARENA), stated that reducing the cost of green hydrogen production was a priority for the government agency. “At AUD $2 per kilogram, clean hydrogen or renewable hydrogen will be cost competitive against fossil hydrogen”, said Miller. To get to this point, Miller suggested that the costs of electrolyser technology and renewable energy would have to decline drastically. Fortunately, since then, renewable costs have dropped rapidly. This has driven an increase in solar and wind-powered electricity in Australia.
An ‘ultra-efficient electrolyser’
In 2022, another piece of the puzzle fell into place in Australia. Technology developer Hysata created an ultra-efficient electrolyser. “Electricity makes up the majority of the cost of green hydrogen”, said Paul Barrett, Hysata CEO. “So, the most efficient electrolysers will produce the lowest cost green hydrogen, which is ultimately what matters to customers.” The design of the Hysata electrolysers boosts efficiency from about 75 per cent to 95 per cent. Therefore, the company believes its technology can play a major part in achieving the ARENA-aligned hydrogen production target of AUD $2 per kilogram. Hysata expects their electrolysers to be commercially available by 2025.
This technological breakthrough is just one of several ARENA-funded electrolyser projects. This government support for green hydrogen production could pave the way for a more cost-effective hydrogen fuel cell, which in turn could incentivise the wider use of hydrogen vehicles in Australia. It is based on this potential that the government has invested in refuelling infrastructure. Its vision is to use Australia’s vast clean energy resources to fuel a truly clean energy transport option. This remains a distant vision for now as several barriers remain in the way.
Lead images credit: Dr. Artur Braun / Wikimedia Commons (CC BY-SA 4.0)