Hydrogen buses are becoming more and more popular every year. Wrocław, Poznań, Gdańsk, Piła – these are just some of the large and smaller Polish cities that decide to include hydrogen buses in low-emission public transport fleets. Let’s look at the possibilities offered using hydrogen as a fuel in public transport.
Over the years 1990-2018, most sectors of the EU economy recorded a significant and regular decline in GHG emissions. These include electricity generation (-497 million t CO2e), the manufacturing industry (-248 million t CO2e), and fuels in the residential sector (-134 million t CO2e). This is certainly not the case for transportation, where there has been a steady increase in emissions.
Hydrogen will play a significant role in transforming existing transportation models and reducing pollution, as it has more potential in long-distance, truck, and bus transportation than BEVs due to shorter refueling and longer range.
Hydrogen as a fuel in buses – advantages
Hydrogen as a fuel in urban bus transport has several advantages over available alternatives. Therefore, interest in including hydrogen buses in city transport fleets is growing every year.
What are these advantages?
High performance
The average range of hydrogen fuel cell buses (FCEV) can exceed 350-400 km, which translates into increased vehicle efficiency and reduced refueling frequency. For comparison, the average range of a BEV bus is approximately 250 km. However, depending on the model and manufacturer, this value may be correspondingly higher.
Short refueling time
The key advantage of hydrogen buses is the short refueling time, which is on average 15 minutes. Charging time for battery buses is longer. Depending on the method, it may be 3-5 hours when using a plug-in charger or approximately 1 hour when using a pantograph.
Zero emission and ecological nature
Considering the use of only zero-emission hydrogen, the operation of FCEV buses does not involve emissions at any stage, and the combustion products are only water and heat. Experts estimate that in this way, a hydrogen bus saves up to 800 tons of CO₂ emissions over a 12-year life cycle compared to a combustion vehicle. The key to determining the zero-emission nature of battery buses is the source of electricity used to charge them.
Noise reduction
Contrary to appearances, the discomfort we experience with loud noise affects not only the proper functioning of the hearing organ but also the entire body – both in terms of physiology and mental health. Electromobility in public transport is not only about reducing emissions but also about making everyday life more comfortable.
Hydrogen bus – how does it work?
That’s right… electromobility. We often forget that hydrogen fuel cell buses are also electric vehicles. Fuel cells, most often located on the roof of the vehicle, operate based on reverse electrolysis, generating electricity while the vehicle is in use.
The fuel cell is powered by hydrogen from tanks installed in the vehicle and oxygen from the air. These then enter a chemical reaction that produces energy and steam. The current is then routed to the drive and battery. Its function is to support the fuel cells during periods of increased energy demand. In addition, energy can be supplied to the battery through recuperation from the braking process.
The only by-products of the reaction are heat and water. Thanks to this, we are dealing with emission-free transport.
Are hydrogen buses safe?
Concerns about the safety of using hydrogen vehicles are still valid, even though they have been operating on roads in Europe for a long time. Of course, regardless of whether we are dealing with a hydrogen, combustion, or electric vehicle, there is always a risk of failure resulting from a fault, system dysfunction, or collision. It is crucial to anticipate such cases at the time of vehicle design.
The use of hydrogen buses is safe primarily because the systems are designed to prevent gas leaks and the risk of ignition during a collision.
Importantly, the very properties of hydrogen mean that in certain cases it can be safer than the well-known and commonly used conventional fuels. Hydrogen is 14 times lighter than air, so when it leaks, it quickly rises in the air (in open space), reducing the risk of ignition. Hydrogen is also characterized by a high auto-ignition temperature in air (585°C). In terms of safety, this is a significant advantage, because at such a high temperature it is more difficult to initiate the combustion process of hydrogen with air without the use of an additional catalyst. For comparison, the auto-ignition temperature of gasoline is approximately 215°C[1]. Unlike it, hydrogen does not pose the risk of creating and igniting a puddle under the vehicle because of a leak.
Hydrogen city buses – regulatory goals
It is not without reason that the attention of decision-makers in Europe is primarily focused on the implementation of hydrogen in urban transport. Also in Poland, it is planned to build infrastructure and ensure the share of zero-emission buses in the fleets of public transport companies.
The consolidated text of the Law on Electromobility and Alternative Fuels indicates that local government units, excluding municipalities with a population of less than 50,000, must ensure that the share of zero-emission or biomethane-powered buses in the fleet of vehicles in use is at least 30% from 2028. According to the Polish Hydrogen Strategy, at least 500 FCEV buses are to be in operation in Poland by 2025, and after 2030 their number is to increase to 2,000.
Poland has one of the three largest bus fleets of all European countries. Of these, in 2019, 12,231 city buses were registered[2]. At that time, approximately 88% were diesel vehicles, and there was not a single hydrogen fuel cell bus in the country.
Over the last three years, we have observed a significant increase in interest in clean technologies in urban transport. One of the reasons is subsidies for the purchase of hydrogen buses for Polish cities.
Hydrogen hubs for transportation – green hydrogen for city buses
The key to introducing hydrogen buses and increasing their number on the streets of Polish cities is to ensure stable supplies of hydrogen fuel at competitive prices. The source of hydrogen itself is also important. The EU’s goal is to use low- and, above all, zero-emission hydrogen, i.e. produced in the electrolysis process using energy from renewable sources. Hydrogen produced in this way guarantees decarbonization at all stages of operation.
A solution that integrates hydrogen production from renewable energy sources, storage, and distribution is a hydrogen hub.
The hydrogen transport hub is a full-scale solution that will enable on-site hydrogen production, ensuring a constant supply of hydrogen fuel to city bus fleets. This is a local ecosystem that allows you to obtain green hydrogen at a favorable price, eliminating the need to supply fuel from outside.
At SES Hydrogen Energy, we see the huge potential of this solution, which is why we implement hydrogen hub concepts aimed at transport applications. We model the most effective configurations, considering demand and energy sources depending on the selected hub structure, to provide green hydrogen fuel cost-effectively today.
Learn more about hydrogen hubs
[1]: ISO/TR 15916:2015 (E)
[2]Central Statistical Office
