Hydrogen is on everyone's lips — but this fuel alternative is by no means a new idea. As early as 1874, science fiction author Jules Verne spoke of hydrogen as an inexhaustible source of energy, inspiring governments and entrepreneurs alike. During the oil crisis of the 1970s, hydrogen reemerged as a potential alternative fuel for cars. Then in 2003, George Bush announced hydrogen vehicles after initial concerns were voiced about climate change. Now, 147 years after Verne's famous novel 'The Mysterious Island,' and at a time when the effects of climate change are becoming more apparent through the burning of fossil fuels, hydrogen is once again in the spotlight.
Hydrogen as a Source of Energy
Hydrogen is the lightest element in the periodic table and accounts for almost 90% of all matter in the universe. On Earth, hydrogen is practically non-existent in its pure form and is found almost exclusively in compounds with other elements. It can form complex molecules, such as organic compounds in plants and animals. Large amounts of hydrogen are stored in nature in the form of natural gas and crude oil. Currently, the production of pure hydrogen almost exclusively uses fossil sources. Although these processes are cost-effective, they do not offer any environmental benefits. The same amount of climate-damaging CO₂ is released during production as with the direct combustion of raw materials such as natural gas and crude oil.
The use of biogas as a raw material and renewable energy for operating plants could improve the environmental impact in this process, but does not offer any advantage over the direct combustion of biogas.
The extraction of hydrogen from water is far more promising. When water is broken down into hydrogen and oxygen with the help of electrolysis, no greenhouse gases are produced, but large amounts of electricity are needed. Although this method is not economical given current electricity costs, it could be a sensible way of storing energy in a climate-neutral manner and making it usable for global mobility if the cost structure changes.
To generate electricity from hydrogen, oxygen and hydrogen react via a proton exchange in an electrochemical cell, similar to a battery. This process generates electric current, low heat and exhaust water, making it a very clean energy source without carbon emissions. Compared to battery technology, hydrogen as an energy source has three decisive advantages — refueling takes only a few minutes, hydrogen only weighs a few kilograms and the electricity is reliably available even at low ambient temperatures.
Hydrogen and Passenger Vehicles
Hydrogen-powered vehicles run on electric motors, as do battery-electric vehicles. Instead of using a battery, the electricity is generated via a fuel cell. Due to the advantages of hydrogen as an energy storage system, car manufacturers and energy companies are investing in this technology — albeit cautiously, as the climate impact of hydrogen available in this industry is still unfavorable.
So far, there are only three fuel cell electric vehicles in select markets: Toyota Mirai, Hyundai Nexo and Honda Clarity. The lack of investment and development has meant that vehicle costs remain high compared to the alternatives. This makes hydrogen a less attractive choice for consumers.
An important building block for accepting hydrogen as a fuel for vehicles is a comprehensive tank network. The necessary investment is subsidized by the state in Germany. In May, the Federal Minister for Economic Affairs, Peter Altmaier, announced that Germany will invest more than 8 billion euros in financing large-scale hydrogen projects. A total of 62 German projects are to receive public funding as part of the European Hydrogen Alliance. They are investments in the future, with the assumption that hydrogen can soon be produced in a cost-effective and climate-neutral manner.
Hydrogen for Buses and Larger Commercial Vehicles
One reason for the state support for hydrogen technology is the fundamental disadvantage of battery-powered vehicles. The large weight of the batteries and the long charging times make operation uneconomical. Hydrogen could be a sensible climate-neutral alternative.
In German public transport, hydrogen has been used in buses since the early 2000s and is now also used in passenger trains (source: NOW GmbH). The use of hydrogen buses is really taking off, with the number of newly registered buses in Europe with hydrogen technology doubling to 50 units in 2020 (source: Welt.de).
Hydrogen and Trucks
Although trucks account for only 2% of vehicles in the EU, they are responsible for 22% of carbon emissions in road transport, according to the lobby group Transport and Environment. Europe's truck manufacturers want to work together to create the right conditions to introduce hydrogen trucks into the mass market. Iveco, Daimler and Volvo have joined forces with the energy companies Shell and OMV to form H2Accelerate to help hydrogen trucks make a breakthrough across the continent.
In Switzerland, Hyundai has started delivering its XCIENT fuel cell vehicles, with a planned roll-out of 1,600 trucks by 2025. The trucks are powered by a 190-kW hydrogen fuel cell and have a range of approx. 250 miles on a single charge.
A possible solution to the current 'chicken and egg' problem of promoting hydrogen supply and developing new hydrogen vehicles could be the creation of 'hydrogen transport clusters.' The aim is to provide access to low-cost, climate-neutral hydrogen for industrial regions with a significant need for road-based freight transport.
Shell and ITM Power are currently developing a refueling network for hydrogen trucks as well as buses, trains and ships for the UK, but there is still a long way to go to achieve this. As there is no significant distribution infrastructure, it could take at least 5 to 10 years before hydrogen can be used on a large scale for heavy-duty vehicles.
It is often argued that all-electric vehicles will be used for shorter ranges, while biofuels will be used for longer distances, so there is no middle course for hydrogen. The decisive factors between hydrogen and battery are usually operational considerations such as range, payload, refueling time and available infrastructure. Powering trucks with batteries is not as easy as it is for cars, as the additional weight means about 4 tons of load capacity—or about 10% per truck—is lost.
These large commercial vehicles simply cannot afford to sacrifice that much payload to accommodate the weight of the batteries.
Hurdles and Challenges of Hydrogen Propulsion
A great deal of work still needs to be done for hydrogen to have a chance of becoming mainstream, from production through to substantial investment in the refueling infrastructure.
The required infrastructure is still far less developed than the EV charging network in Germany. According to H2.live, the basic network for 700 bar refueling will reach 100 stations in the coming months, whereas the number of charging stations for electric vehicles in Germany stood at around 23,800 in July 2021 (source: Statista). As a result, the prevalence of fuel cell vehicles is significantly lower than that of battery-electric vehicles.
In addition, the growing production of hydrogen vehicles will benefit from economies of scale (including automation and digitalization), a process that gasoline, diesel and electric vehicles have already undergone. At the same time, scientists are working tirelessly to improve the hydrogen production process and have already made significant progress in recent years. Finally, the cost of carbon emissions is expected to rise significantly, which also makes green hydrogen more attractive.
What Would Verne Say?
Almost 150 years after Jules Verne first imagined a hydrogen-powered world, it is still not clear how forward-looking this idea really was. Significant investment by private companies and governments in battery-electric technology has led some observers to declare that the race to become the preeminent environmentally friendly energy source is over.
While this blog focuses on notable developments for hydrogen-powered buses and trucks, it may be the benefits of hydrogen for ships and airplanes that will confirm Jules Verne's vision in the near future.
