Mobility giant Daimler Truck (Daimler) has developed a new refuelling technology for subcooled liquid hydrogen – or sLH2 – alongside Linde Engineering (Linde) to accelerate the efficiency of hydrogen-fuelled trucks and advance filling stations as a carbon dioxide (CO2)-free alternative to today’s global diesel standards.
Heavy-duty vehicles are responsible for more than 25% of greenhouse gas (GHG) emissions from road transport in the EU and account for over 6% of total EU GHG emissions, according to EU figures.
The recent popularity of hydrogen as a fuel has seen the development of over 250 hydrogen refuelling stations (HRS) across Europe.
The majority of public stations today dispense gaseous hydrogen, however, stations where LH2 storage is emerging due to larger demand.
Developed by engineers from both companies, the partners claim that the sLH2 process allows for a higher storage density, greater range, faster refuelling, lower costs and superior energy efficiency when compared to gaseous hydrogen.
The new process uses a new sLH2 pump to slightly increase the pressure of the liquid hydrogen, making it subcooled. This enables a refuelling time of around ten to fifteen minutes for a 40-tonne heavy-duty truck, carrying 80kg of LH2 for a range of 1,000km and more.
“Subcooled liquid hydrogen considerably increases the efficiency of hydrogen refuelling systems,” explained Juergen Nowicki, Executive Vice President Linde plc and CEO of Linde Engineering. ”
By increasing its efficiency, the technology may lower the required investment for a hydrogen refuelling station (HRS) by a factor of two to three with operational costs recorded at five to six times lower.
“This and further advantages make sLH2 a practical, CO2-neutral alternative to diesel in the heavy-duty vehicle sector. The technology we have developed with Daimler Truck will help pave the way for the development of a robust refuelling network.”
The partners also report minimal energy losses during refuelling compared to conventional LH2. In conventional systems, part of the hydrogen evaporates when it is filled into the tank.
This must then be extracted through a second line – a costly process that Linde says requires complex communication between the fuel pump and the vehicle.
The pilot sLH2 refuelling station – which needs no data communication between the HRS and the vehicle – has a capacity of 400kg of LH2 per hour.
“In terms of hydrogen infrastructure, we are reaching a major milestone today: With sLH2, hydrogen refuelling becomes as convenient as today’s refuelling with diesel,” said Andreas Gorbach, Member of the Board of Management of Daimler Truck AG (Daimler).
Located in Wörth am Rhein, Germany, the new public sLH2 refuelling station boasts an energy consumption rate of 0.05 KWh/kg (kilowatt hours per kg) – approximately 30 times less energy compared with conventional gaseous hydrogen refuelling.
The future of hydrogen in European heavy goods transport
Diesel dominates heavy goods transport, yet hydrogen is rapidly becoming a compelling low emission alternative.
According to research by Interact Analysis, heavy-duty trucks will be the most common application of hydrogen in transportation in 2030.
Many hydrogen strategies and roadmaps have been announced by the authorities of European countries that target the use of fuel cell technology for zero-emission trucks.
In the Netherlands, the National Climate Agreement has specified an ambitious target for hydrogen, including 3,000 fuel cell heavy-duty vehicles by 2025.
The State of NRW in Germany has set a target of 11,000 fuel cell trucks of over 20 tonnes by 2030, while Spain’s target of 5,000 fuel cell trucks by 2030 was proposed in the Spanish Hydrogen Roadmap.
A similar initiative has been seen in the Czech Republic, whose strategy features a forecast for future hydrogen consumption in transport, including 4,000 hydrogen trucks by 2030.
The Italian National Hydrogen Strategy Preliminary Guidelines outlines the country’s target to power 2% of its heavy long-haul trucks by hydrogen fuel cells by 2030.