Hydrogen fuel cells and rechargeable batteries are the two likeliest power sources for tomorrow’s electric vehicles. While economics, convenience, and sustainability will determine which power system dominates, it’s clear that fuel cells have several advantages over batteries. Reviewing these advantages, and some of the drawbacks, may provide insights into where we are headed.
Where Fuel Cells Excel
Fuel cells have a clear advantage when it comes to refueling speed. Although many technologies are being developed for faster battery charging, the physics involved will always be more time-consuming than transferring hydrogen. What’s more, hydrogen refueling is very similar to how gasoline- and diesel-powered vehicles are now refueled: You simply drive up to a pump and fill up your tank. In fact, in its early stages, one or two hydrogen pumps could easily be installed at many existing gas stations to satisfy market demand.
Hydrogen-powered vehicles also typically have a much longer range than battery-powered vehicles due to the amount of energy they store. If we’re talking about a pure fuel-cell system, not a fuel-cell hybrid connected to a battery system, fuel cells have a longer lifespan.
Finally, even though fuel-cell-powered vehicles use batteries, a complete fuel-cell system including batteries is much lighter than the batteries needed to power a vehicle. That means the vehicles weigh less.
A Question of Cost
The biggest question surrounding hydrogen fuel cells is the cost — of the fuel cells themselves and the hydrogen. A 50-kilowatt fuel cell system currently costs about $50,000, to which you must add the cost of the system’s fast charging and discharging storage mechanism, known as supercapacitors, which also are expensive. The good news is that supercapacitors are at least 98% to 99% recyclable. As a result, fuel cells are expensive compared with batteries.
Then there is the cost of hydrogen. Although hydrogen is the most sustainable and abundant resource on the planet, it typically must be extracted or chemically freed from a substance or compound in which it is a component. Water is the usual source of hydrogen, and through a process known as electrolysis, or electrochemical water splitting, electricity is used to separate water into hydrogen and oxygen. “Green” hydrogen, a popular term today, means using a sustainable power source, such as solar, wind, hydropower, or geothermal, to electrolyze water. But producing “green” hydrogen can be expensive.
Another big expense is the platinum that fuel cells require as a catalyst to promote the electrochemical reactions to create electricity from hydrogen. Platinum, of course, is a rare and expensive mineral. Since so few fuel cells are currently used, the price of platinum hasn’t been a big issue, but as the use of fuel cells grows, costs will mount. At that point, pressure will increase to encourage technological innovation permitting a switch to a much less expensive and more sustainable metal.
Storage and Distribution Issues
Unlike a gasoline tank, which is a relatively inconsequential part of the total cost of a car or truck, a hydrogen tank is a very expensive component because it is made of wrapped carbon fiber to withstand the pressure of holding hydrogen in either liquefied or gas form. The amount of steel or aluminum needed to contain the required pressure would make conventional tanks too heavy. Transportation is also expensive, requiring light but pricey wrapped carbon fiber tank trucks. While hydrogen pipelines and other distribution systems are in consideration, those too are expensive.
In this regard, battery-powered vehicles present their own issues. Since electrical generating capacity can’t be increased overnight, any quick change to battery-powered vehicles would require an increase in recharging stations — whether at commercial facilities or at home. Each recharge pulls something on the order of 400 amps, so it’s not like plugging in an extra tea kettle. Power grids would have to be seriously upgraded.
The Commercial Market
Over the past 12 months, the fuel cell market has seen enormous growth, especially for use in transit buses, commercial vehicles, and heavy off-road equipment, including mining trucks. These are “back-to-base” uses in which a vehicle leaves from a base operation that can accommodate a hydrogen refueling station and can return relatively easily for a fast refueling even after covering a long range. The downtime for these vehicles is minimal, and even though they are about twice as expensive as equivalent diesel-powered vehicles initially, they have fewer moving parts, last much longer, and require much less maintenance. Therefore, their total cost of ownership is lower than a vehicle with an internal combustion engine. They are also more reliable.
At present, some major fleet operators are testing fuel-cell vehicles, seeing how they perform against their current vehicles. Once these tests are completed, maybe in six months to a year, and fuel cells prove themselves, we’re likely to see more rapid growth.
About Ian Thompson
Currently Chief Technology Officer at H2X, an Australian hydrogen fuel cell vehicle and powertrain manufacturer, Ian Thompson formerly was CTO of Hyzon, Chief Engineer for Grove Hydrogen, and Director of Interiors at Karma Automotive. With 29 years of experience in the automotive industry, he has held a variety of roles at companies including Maserati SPA, SenseAir AB, and Grupo Antolin, a manufacturer of premium interior components, working with major original equipment manufacturers including Ford, GM, Chrysler, Toyota, Hyundai, Renault/Nissan, Aston Martin, and Bentley. He also is an investor and Head of Design at AddMovement AB.
This automotive industry article is adapted from the GLG Roundtable “Hydrogen Fuel Cells vs. Batteries: Which Will Fuel the Electric Vehicles of the Future?” If you would like to speak with automotive industry experts like Ian Thompson or any of our approximately 1 million industry experts, contact us.