Hyzon has completed its first commercial trial of a liquid hydrogen fuel cell electric vehicle, making eight deliveries in Texas over more than 540 miles (870km) without refuelling in a single 16-hour run.
While the firm has currently designed its trucks around gaseous H2, liquefied hydrogen could offer greater energy density without increasing the total vehicle weight — even accounting for the need to keep it cooled below minus 253°C.
“With increased range and no added weight in comparison to our gaseous hydrogen trucks, we believe this liquid hydrogen demo run has demonstrated potential viability for the future of liquid hydrogen in commercial trucking,” said Hyzon’s CEO Parker Meeks.
“The results we captured in the strenuous demo through Central Texas’s diverse terrain and summer heat make us optimistic that, once commercialized, our liquid hydrogen vehicle powered by our proprietary 200kW fuel cell system should be able to provide long distance range between 650 and 800 miles, on par with many diesel truck range requirements,” he added.
Cryogenic storage tanks were provided by Chart Industries, which effectively maintain extremely cold temperatures passively with a vacuum seal between two walls.
However, if some of the stored liquid hydrogen warms up beyond minus 253°C, it will turn to H2 gas, expanding in the process and increasing the pressure inside the tank, which could potentially build up and cause it to explode unless the gas is released — either into the atmosphere, where it acts as an indirect greenhouse gas, or to be reliquefied, a far more expensive and complex option.
Hydrogen Insight has reached out to Hyzon and Chart Industries to confirm whether there was any boil-off as a result of the truck running in “100-degree Fahrenheit [37.8°C] temperatures” during the trial.
Despite the risk of boil-off, liquid hydrogen is generally considered to reduce overall costs during refuelling due to the higher energy density by volume than compressed gaseous H2.
Hyzon cited figures from Argonne National Laboratory that liquid hydrogen could cost $5/kg less than gaseous H2 at the pump. And recent modelling by Australian government science agency CSIRO puts offsite hydrogen production with liquid H2 trucked to refuelling stations (with a daily 4,500kg throughput) as the most effective route to keep pump prices down.
“Simply put, we see liquid hydrogen as the economical approach to long range zero emission trucking,” Meeks added.
However, it is unclear whether existing Hyzon trucks — which use fuel cells running off gaseous H2 — can be retrofitted with liquid hydrogen systems in future.
Hyzon is currently in the midst of being investigated by the US Securities and Exchange Commission over allegations of fake customers and exaggerated orders in its financial statements.
And an internal investigation admitted in March this year that more than half of its 87 vehicles delivered in 2021 were not operable or required post-delivery repairs, prompting a revision of recognised revenue in its reports.
While at the time, stock exchange Nasdaq threatened to delist the company due to delays in filing the new reports and shares trading below $1 for ten consecutive days, Hyzon has regained compliance on both these points.