Hydrogen and diesel are two energy sources that are often seen as competing technologies, but they have both strengths and weaknesses. Scientists, such as Cummins and Volvo Trucks, believe that they can be used to power both hydrogen and batteries in heavy trucks. Hydrogen is an energy storage medium, and is not a traditional fuel in a traditional context. It is estimated that windmill-to-wheel conversion efficiency for hydrogen is around 60%, meaning 40% of the harvested energy is consumed in the process. Diesel engines are less than 50% efficient at turning the chemical energy in diesel fuel into kinetic energy to move trucks.
Batteries are heavy and expensive, but cost and weight are both constantly improving and are often charged to only 80% of their rated capacity, which compromises range. The North American Council for Freight Efficiency (NACFE) cautions that batteries should not be oversize or overheat, as it could impact freight weight capacity and range. Rick Mihelic, director emerging technologies at NACFE, suggests that regenerative braking opportunities should be considered when considering range. There are environmental consequences associated with mining raw materials and producing batteries, but they offer a relatively easy connection to a power source through an electric grid. Hydrogen production from renewable sources is still costly, but the price is dropping and the technology and its deployment are still relatively new.
Cummins is upscaling its hydrogen development, recognizing the need to replace much of the current "grey" hydrogen production with "blue" or "green" forms. Alberta is a leader in blue hydrogen due to abundant natural gas and work on carbon sequestration. Almost all the hydrogen produced today is grey, which is generally produced through steam methane reforming, using significant amounts of power from natural gas. The future lies with hydrogen produced by electrolyzers powered by renewable sources. In the early stages of battery and fuel cell technologies, hydrogen advocates argue that lighter overall vehicle weight is one of the top advantages of fuel cell systems over batteries.
At least two fuel-cell truck producers, Nikola and Hyundai, have said fuel cell trucks with a range of 500 miles will have curb weights around 18,000 to 20,000 lb., making them competitive with diesels. NACFE and vehicle specification sheets from Hyundai suggest that fuel cell tractors are expected to be 4,000-5,000 lbs. heavier than diesel units, but still somewhat lighter than battery-electric trucks. Hyundai recently announced a 36-tonne 4×2 tractor with a Range of 250 miles (400 km) has a curb weight of 21,560 lb. This is the battery range with just two axles, not the 500-mile range on a 6x2 platform North American carriers want in a longhaul truck.
Daimler Truck and Volvo Trucks have also announced ambitious plans for fuel-car-powered trucks in a program called cellcentric, with operations slated to begin in 2025. Hydrogen fuel cell technology is becoming increasingly popular in Europe, China, and North America, with the potential to become a viable alternative fuel. Canada has developed a hydrogen strategy and is rich in the feedstocks that produce hydrogen. Stenqvist believes that the amount of hydrogen produced in the world today needs to increase by five to seven times, and that the final product must be competitively priced. He believes that if trucking was the only industry relying on hydrogen in the long run, he would be more concerned than he is today. However, many other industries are committing to hydrogen today and need sources of cheap clean hydrogen.