Picture a semi-truck hauling cargo down a highway. Are there clouds of black smoke left in its wake? Not if the truck is powered by hydrogen fuel cells.
But the transition from the combustion engine to fuel cell motors faces an infrastructure hurdle: Only 44 hydrogen refueling stations exist in the United States; 42 of those are in California.
Commercial semi-trailer trucks, however, could be the catalyst for the development of more hydrogen refueling stations. These trucks can drive many miles between refueling, which means they’d require fewer refueling stations along heavily trafficked routes. Transitioning these trucks to clean energy would cut about 20 percent of transportation-related greenhouse gases in the United States. So, developing a dependable, long-lasting hydrogen fuel cell for trucks that can haul everything from food to furniture is the focus of a new Department of Energy project called the Million Mile Fuel Cell Truck (M2FCT), co-led by Los Alamos National Laboratory.
“The hydrogen fuel cell program has been around since the 1970s, and it’s the longest-running, non-defense program at Los Alamos,” says Rod Borup, program manager for the Lab’s Fuel Cells and Vehicle Technology group. “These clean engines could one day power planes, ships, and trips to the grocery store.”
Here’s how a hydrogen fuel cell engine works: Hydrogen gas is stored in a vehicle’s tank (similar to how gasoline is stored in a tank). The hydrogen is then piped to the fuel cell stack, where the oxygen and hydrogen react on separate sides of 10- to 20-micron-thick platinum-coated membranes. These membranes are where electrons are then stripped from hydrogen atoms, the result being electricity. This electricity, combined with electricity from a lithium ion battery and also from regenerative braking, then powers the vehicle.
“The hydrogen fuel cell program has been around since the 1970s, and it’s the longest-running, non-defense program at Los Alamos. These clean engines could one day power planes, ships, and trips to the grocery store.” —Rod Borup
Why isn’t just a battery sufficient? Well, an electric sedan needs about eight hours to charge its battery. Semi-trucks, with the massive batteries they’d require, would take much longer. But refueling hydrogen takes about as much time as filling up a gas tank. So, if a string of hydrogen stations could be built along major interstates, semi-trucks could operate continuously—and cleanly—with minimal extra infrastructure along those routes.
Semi-trucks average about 45,000 miles per year, and all that driving results in a lot of wear and tear. For hydrogen-powered trucks, this especially affects the thin platinum-coated membranes where electricity is created. The heat generated from this process can cause the membranes to degrade.
“For heavy-duty trucks, durability is a big piece of what we’re trying to solve,” Borup says. “We want to prove it can make one million miles, which is why we’ve named the project The Million Mile Fuel Cell Truck.”
At the Lab, researchers used heat and gases to accelerate the wear and tear on a fuel cell, mimicking the punishment of driving one million miles. Then, they tried different ways to alleviate the wear and tear. Altering the microscopic structure of the platinum, for example, reduces its deterioration. Scientists also introduced cerium, a benign material, into the fuel cell to capture the chemicals that typically degrade the membrane, extending the fuel cell’s life.
The M2FCT program has been funded through 2025, at which time Los Alamos hopes to complete its million-mile-capable fuel cell. Meanwhile, to solve the problem of refueling along trucking routes, a second Department of Energy initiative is refining the process of splitting water into hydrogen and oxygen through electrolysis, a process that could be used to create hydrogen fuel from renewable energy sources such as wind and solar.
With these solutions in the works, a new breed of clean-energy trucks may soon cruise American highways.