Instead of harmful fumes, the tailpipes of hydrogen-powered vehicles emit nothing other than pure H2O – more commonly known as water. This key feature makes hydrogen (H2) not only a popular source of energy for fuel-cell vehicles, but also a key stepping stone in the move towards a climate-friendly energy economy. The hydrogen in fuel cells produces clean electricity when it reacts with oxygen (O2) to form water. This process does not create any harmful exhaust gases. It is an attractive idea that has been around for some time now. In fact, the writer Jules Verne foresaw a hydrogen-based energy economy as far back as 1874. “Water will be the coal of the future,” wrote Verne at the time. Now, almost 150 years later, Verne's vision is slowly taking shape. Producing H2 is still a cost- and energy-intensive process. However, excess electricity from renewable energy sources that is not required during off-peak periods is an excellent way of producing green hydrogen.
The production capacity for green hydrogen is increasing worldwide – driven by the transition to more sustainable energy systems. More and more of Europe’s energy is sourced from increasingly efficient solar farms, ever-bigger wind farms and hydropower plants. In 2018, energy from these sources accounted for 16.8 percent of all energy consumed in Germany. Scandinavian countries are even further ahead here, with renewables accounting for 40 percent of the energy mix in Finland, over 50 percent in Sweden and 70 percent in Norway.
The key challenge with renewable energy, however, is the fact that it fluctuates. In strong winds, for example, wind farms produce more power than the grid needs. The same applies to solar farms on sunny days. “If we use this green energy for electrolysis, we can store it as hydrogen and transport it too,” explains the Linde expert. The green hydrogen can be distributed to hydrogen fueling stations, for example, of which there are already more than 80 in Germany. The H2 Mobility Deutschland initiative aims to expand this network of fueling stations to 400 sites by 2023, creating an extensive infrastructure for fuel-cell cars across Germany. Linde is also an active member of this project.
Refueling with hydrogen
Germany already has over 80 hydrogen fueling stations like this one here in Berlin. Linde is a member of H2 Mobility Deutschland, an initiative that aims to expand the German network of fueling stations for fuel-cell cars to 400 sites across the country by 2023.
Expanding the H₂ fueling infrastructure
Following Germany’s example, Japan has founded “Japan H2 Mobility” – a company aiming to build 170 hydrogen fueling stations in Japan by 2021
Getting H₂ into the car
Hydrogen is typically transported as a compressed gas to fueling stations such as this one in Stavanger, Norway.
H₂ – ready to fuel
Linde’s patented ionic compressor uses five hydraulic pistons to gradually compress hydrogen to the right pressure. The gaseous H₂ can then be used to fuel vehicles – at a pressure of 700 bar for passenger cars or 350 bar for larger vehicles such as buses and trains.
Bursting with energy – liquid hydrogen
H₂ is transported by tanker to most fueling stations as a compressed gas. Linde also offers a concept that enables hydrogen to be stored as a liquid (LH₂), capitalizing on the advantageous fact that LH₂ has a much higher energy density.
