Something is bubbling next to Thomas von Unwerth, who is seated at the conference table in his office. At the far edge of the table, a mini-electrolyzer is separating water into its individual components thanks to electricity from a solar cell. In one of the two tubes, the substance of this engineer’s dreams bubbles upward: hydrogen. H2.
“Fossil fuels are finite, but our stocks of hydrogen are nearly inexhaustible,” von Unwerth explains. “In the oceans alone, there is enough of it to meet humankind’s energy needs for 50 million years.” To be fair, he directly addresses the obstacles associated with this scenario: “Hydrogen is only found bound up in molecules, which means we always have to obtain it first. If we want to do this in a climate-neutral manner, we have to release it using renewable energy. Afterwards, it can easily be stored and transported. Much better than electricity.” As an alternative, using hydrogen that occurs as an industrial byproduct could also be tested.
In von Unwerth’s opinion, his technology’s second advantage is that electricity can be generated from stored hydrogen as needed. The critique that half of the original amount of energy is lost in the process—for batteries it’s only about 10 percent—doesn’t ruffle him: “That’s true, but rather than let excess energy, especially green energy, simply go to waste unused, it would be preferable to store it in the form of hydrogen and use it later, even if it’s only half as much.”
Increasing numbers of bubbles gather in the electrolyzer as von Unwerth continues: “Hydrogen vehicles can be fueled in just a few minutes, even larger ones such as buses or cargo trucks. Refueling is much faster than it is for electric-battery vehicles—and the operating range ƒis greater.” However, he adds, the filling station infrastructure remains inadequate. Right now, around fifty filling stations offer hydrogen in Germany, while experts estimate that around one thousand would be needed. Von Unwerth is well aware that this isn’t enough for an extensive market breakthrough: “A lot more needs to happen in this area, but things are moving forward. By 2019 there should be about one hundred filling stations and more and more after that.” He gets up from the conference table and smooths his shirt. Then he heads down to the laboratory on the ground floor to approve a performance test for new fuel cells. Along with increasing performance, the engineer and his team are also working on reducing the fuel cell’s complexity. “At the moment it’s made up of about six hundred individual parts, which is far more than a battery has,” he says while walking down the stairs. “So that makes fuel cells too expensive right now. We’re looking for ways to make mass production cost-effective. We need the volume effect to establish fuel-cell technology on the market.” The raw materials costs must also be optimized for this. But von Unwerth believes things are on the right path. In the past, for instance, around 100 grams of platinum was required in a fuel cell, while now it only needs just 10 grams. “And this shouldn’t be a problem as there’s just as much in the catalytic converters for combustion engines,” he says. “You just have to reallocate the resource.”
He opens the heavy, metal door that leads into the laboratory. The two rooms are packed full of test stations. The gases needed for fuel cell research—which include oxygen, argon, hydrogen and high-purity hydrogen—are distributed through thin brass tubes running in parallel along the walls and ceilings. There’s a test in the fuel cell system laboratory scheduled for today. The four hundred cells have already been placed in a row, and their performance in the entire vehicle system is being closely scrutinized. “As soon as we supply the hydrogen, four hundred columns will rise up on the monitor—we call this the picket fence,” von Unwerth explains. “Each column represents the voltage in a cell.” The experiment is started and the cells are subjected to stress. “The moments when the load on the cells is increased and decreased are always the most exciting for me,” he says. “That’s when it becomes clear whether they are stable and respond evenly.” The testing measures few fluctuations today, pleasing von Unwerth.
He is certain that, very soon, fuel cell technology in electromobility will be making some major advances. “The first German carmakers have announced they’ll be mass-producing hydrogen-powered vehicles in appreciable quantities at the start of the next decade,” he says. “The topic even seems to have arrived at the political level. In the previous government coalition agreement, fuel cells weren’t mentioned at all. In the current one, they’re mentioned at least seven times,” he adds with a laugh.
Looking to the future, there’s no question for the fuel cell expert about which technology will be calling the shots in electromobility:
“Both,” the two of them agree. But their reasoning differs. “Batteries and fuel cells complement each other,” von Unwerth says. “Batteries provide power immediately, while fuel cells need a little longer when you step on the gas. So hydrogen-powered vehicles also need a battery in order to quickly reach peak power. Conversely, battery-driven vehicles can benefit from the range that fuel cells provide. I think fuel cells and batteries complement each other to form a fully-fledged propulsion system. We need highly efficient batteries that are smaller, more durable, more powerful and more environmentally friendly.” He also feels that batteries by themselves are not an option for the masses: “Right now there are than 1.3 billion vehicles worldwide, and the trend is rising. I think it is impossible to set up a charging station infrastructure for so many vehicles.” Wolter agrees: “Setting up a charging infrastructure of this size is certainly challenging. But I think it would therefore be better to focus on more efficient concepts for mobility, which could include car sharing and expanding public transport systems as examples.”
There’s also another reason Wolter doesn’t think that her work is competing with research into fuel cells: “There are scenarios in which battery-driven electric vehicles work well, in urban spaces for example, and others in which fuel cells are better, for heavy-cargo transport for instance.”
The scientists also agree that there must be more political pressure to get electric mobility moving in Germany. “Why should car manufacturers go out on a limb if they have cars with internal combustion engines that are still selling like hotcakes?” von Unwerth asks. “Many consumers simply don’t like the electric cars available at the moment, or they are too expensive for them. Legislators need to do something about it.” Wolter would like to see more government involvement in financing: “In China, where legislation requires it, German carmakers are already implementing major projects in the field of electromobility, but in Germany there is a great reluctance to make any financial commitments when research is still at an early phase.” So both researchers are hoping politicians will do something about it—and otherwise see themselves in peaceful coexistence: “Everything will find its place”, they say.