Hydrogen cars: A look at the pros and cons
Leading manufacturers like Hyundai and Honda are showing growing interest in hydrogen-powered vehicles, actively exploring hydrogen technology as a promising path to sustainable transportation.
As the world strives for net zero by 2050, hydrogen emerges as a good option, due to its potential to decarbonise the automotive industry. China has set a goal to have 50,000 fuel cell vehicles on its roads by 2025, according to its hydrogen development plan that was released in 2022.
Understanding Hydrogen Combustion Vehicles
Hydrogen combustion vehicles operate through a process where hydrogen gas is injected into the engine's combustion chamber and ignited, similar to how gasoline ignites in traditional combustion engines. Hydrogen combines with oxygen from the air, generating energy to power the vehicle and emitting only water vapour as a byproduct.
Despite the environmental benefits, hydrogen combustion engines face efficiency challenges. Combustion engines, whether powered by hydrogen or gasoline, are generally less efficient than fuel cell systems. This is due to significant energy losses during the combustion process, as a large amount of energy is dissipated as heat rather than being converted into useful mechanical energy. Fuel cells, by contrast, achieve much higher efficiency by directly converting hydrogen into electricity through an electrochemical reaction.
Take a look at this video from Toyota, showcasing their hydrogen-powered Toyota GR Yaris H2 Concept with a hydrogen internal combustion engine at Goodwood:
The Role of Fuel Cells
Fuel cell technology is at the heart of hydrogen innovation, offering a clean and efficient alternative to combustion engines. Fuel cells generate electricity through a chemical reaction between hydrogen and oxygen, with the only byproduct being water vapour. This process creates a continuous flow of electricity to power the vehicle's electric motor.
Fuel cell technology boasts high efficiency, converting hydrogen into electricity with minimal energy loss.
In the automotive sector, fuel cells are often favoured in comparison to combustion vehicles, for their efficiency and long driving range, while hydrogen combustion vehicles can be praised for their simpler technology and potential use in the existing infrastructure.
Hydrogen in competitive racing
Toyota's latest hydrogen-powered GR Corolla has introduced a liquid hydrogen fuel system to competitive racing. Unlike traditional hydrogen setups that release vaporised hydrogen into the atmosphere, Toyota is working to capture and repurpose this gas, which forms naturally when liquid hydrogen is exposed to heat. By harnessing the boil-off gas, Toyota aims to generate additional energy for the vehicle, boosting overall system efficiency and reducing energy waste, an innovation that could revolutionise hydrogen transport.
To achieve this, Toyota has developed a self-pressuriser that uses the existing pressure of the boil-off gas, eliminating the need for external energy input to convert it back into usable fuel for the engine. Surplus boil-off gas is also directed into a small fuel cell, which generates electricity to power other vehicle systems, such as the hydrogen pump. This process not only increases the vehicle's energy efficiency but could also reduce dependence on external energy sources, helping Toyota move closer to its carbon-neutral goals.
Read more about Toyota's innovation on their website.
This development builds on Toyota's work from 2023, when they introduced a liquid hydrogen-powered car for competitive racing. The Toyota GR Corolla competed in the Fuji Super TEC 24 Hour Race, becoming the first vehicle in racing history to use liquid hydrogen. The switch to liquid hydrogen provides significant benefits over gaseous hydrogen, such as lighter components and fewer pit stops, making the vehicles more competitive in racing and more practical for everyday use. Liquid hydrogen also allows refueling at the same locations as gasoline-powered cars, providing added convenience.
Hydrogen Fuel Filling Stations
Fuel Cell Electric Vehicles (FCEVs) and hydrogen combustion vehicles both require pressurised hydrogen to run, which can be purchased from hydrogen fuel filling stations. Refilling takes approximately 3-5 minutes for a car.
As of December 2023, the UK has 16 operational hydrogen fuel stations, but the infrastructure is still in its early stages. Hydrogen-powered cars are gaining momentum, but their widespread adoption is hindered by limited refueling options, making it a significant challenge for prospective buyers. The government, however, has ambitious plans to significantly expand this network in the coming years to meet growing demand.
The Hydrogen Council, an industry body, forecasts that by 2030, there could be 13 million fuel cell vehicles in use worldwide, including 1 million vans, trucks, and buses.
Countries such as Germany, China, and the United States are at the forefront of hydrogen innovation, making significant strides in implementing hydrogen infrastructure and attracting substantial investment in the technology.
Hydrogen energy cars pros and cons
There are many advantages of hydrogen energy cars, but the technology does come with its challenges as detailed below.
IGEM Member experience
George Brookfield, CEng MIGEM and Hydrogen Operations Project Delivery Manager at Cadent, is a proud owner of a Hyundai Motor UK hydrogen vehicle. He recently took to the roads for an exploration of hydrogen refuelling at Motive Fuels in Rotherham. His firsthand encounter left him pleasantly surprised by the simplicity and efficiency of the refuelling process.
"I’ve just refuelled my hydrogen car for the first time today, I was pleasantly surprised how simple the process was, I was in and out in 5 minutes."
The Hyundai NEXO operates on a hydrogen fuel cell system, merging oxygen and hydrogen to generate a continuous flow of electrons. This process propels the electric drive while also charging the battery. The NEXO can travel 413 miles on one charge. This makes it a great option for commuting to work or going on road trips.
Enthusiastically venturing into longer distances, Brookfield embarked on a journey showcasing the potential of hydrogen powered vehicles. His itinerary was a testament to the capabilities of hydrogen in vehicles, clocking 343 miles across various destinations.
"By my maths, the car has a 413 mile range if I had a full tank, which would cost around £165, it works out to about 40p per mile. The technology has a bit of a way to go to compete with petrol and diesel cars which are around 15-20p per mile!"
Reflecting on the cost and efficiency, Brookfield acknowledges the differences between hydrogen and traditional fuel costs, highlighting the need for widespread adoption to bring the costs down.
Brookfield's experience showcases the potential of hydrogen cars, emphasising the ease of distance driving and fast refuelling, although acknowledging the ongoing actions needed for affordability in comparison to conventional fuels.
