“We try not to have lunch here or have guests stay too long,” Arne Jacobsen, a Vattenfall business development manager, said in a room where hydrogen gas was stored in pressurized tanks. Hydrogen can be volatile if it escapes into the air.
The filling station in Hamburg, part of several bets on hydrogen in this German port city, reflects the great appeal, and challenge, of this clean fuel.
Under the technology, hydrogen gas runs through a fuel cell. There, the gas is mixed with oxygen, a process that generates an electric charge to power the vehicle. The only emission produced is water vapor.
Hydrogen vehicles also offer advantages over battery-powered counterparts. They have a longer range and can be refueled quickly, like a gasoline or diesel vehicle.
As the United States retreats from its global leadership role on climate change, countries like Germany are aggressively moving ahead, testing all manner of clean energy initiatives. The German government, along with private companies like Royal Dutch Shell, Daimler and the industrial gas giant Air Liquide, has invested about €1.4 billion over the past decade to nurture the development of hydrogen vehicles.
In Hamburg, Germany’s second-largest city and busiest port, the money has helped build a small network of filling stations, encouraged road trials of hydrogen-powered city buses, and funded research. Daimler is planning to introduce a hydrogen-powered S.U.V. this year.
But the financial support has not yet translated into commercial success.
Germany has only about 260 passenger cars on the roads, and 16 buses, that are powered by hydrogen fuel cells. By comparison, there are about 55,000 battery and plug-in hybrid cars across the country.
This year, hydrogen faced a big setback, when Toyota, one of the largest producers of such vehicles, recalled all of its Mirai hydrogen-powered cars. Although Toyota continues to back hydrogen vehicles, other big automakers are increasingly betting on electric cars.
“We do see some expectations that were not met,” said Klaus Bonhoff, head of the National Organization Hydrogen and Fuel Cell Technology, which manages the government’s programs involving the fuel. Despite the disappointments, Mr. Bonhoff said that the government was likely to continue supporting hydrogen because more than one technology would be needed to reduce emissions.
As much as anywhere in Germany, Hamburg, a graffiti-festooned center of youthful and commercial cool, has thrown its weight behind hydrogen and other clean energy technologies.
The regional authorities want to reduce air pollution from the growing volumes of traffic on the roads and from smoke-belching cruise liners and other ships in the port, while at the same time stimulating business and jobs based on clean energy. In another green wrinkle, making hydrogen on a large scale could soak up excess electricity produced by the many wind farms near Hamburg.
While some of these efforts are a long way off, one project, a commuter train, is close to fruition. This year, the hydrogen-powered train took its first test through the woods, running about 50 miles an hour. When done, it could go up to 85 m.p.h.
“This is our baby,” said Stefan Schrank, the prototype project manager for Alstom, the train’s French manufacturer. “We are very proud.”
The company is trying to find a role for the gas that makes economic sense.
About 40 percent of Germany’s rail network is not electrified. And Alstom executives say that it would be cheaper to replace the diesel-powered trains with hydrogen vehicles than to string electric lines along the tracks.
Alstom says it has preliminary orders for 50 to 60 trains from German regional authorities. If the orders are fulfilled, Mr. Schrank estimated the project would break even, based on the investments by Alstom and the German government, which has put in €8 million ($8.9 million).
A commuter line like this one looks well-suited to hydrogen. The company can build a fuel supply system in a safe place like a rail yard of its choosing.
“Every night we know where the train is coming,” Mr. Schrank said. “We can fill it.”
Using hydrogen on an airplane, which would need to fly all over the world, would be trickier. Airbus has experimented with using hydrogen to power a plane’s emergency electrical systems and when it is on the ground, potentially a big pollution reducer.
But Airbus is reluctant to install these systems on a large number of planes until there is a worldwide network of fueling facilities. “Our aircraft do go to some very remote places,” said Barnaby Law, the company’s project director for hydrogen and fuel cells, who is based in Hamburg. “It has to be economically feasible.”
Even a car or bus network is challenging. Hamburg has four hydrogen filling stations — which are enough, provided that a motorist is careful.
The price, too, is proving prohibitive. Hydrogen passenger cars can cost nearly double their electric counterparts.
The city’s bus operator, FFG, which is required in the coming years to shift to buses with zero emissions, is testing six partly hydrogen-powered buses as part of a low-polluting trial fleet of about three dozen vehicles. The buses are essentially custom built, costing about four to six times the price of a diesel-powered bus, according to Philip Thetens, a vehicle technology executive at FFG. And they are prone to breakdowns that can be difficult to fix.
The technology also faces a perception problem stretching back to the Hindenburg air disaster in 1937, when a hydrogen-filled airship exploded in New Jersey. Industry executives say that they have developed equipment and procedures to make the handling of hydrogen safe.
“There is so much disinformation about hydrogen,” said Thomas Bystry, who is in charge of the hydrogen filling stations in Germany at Royal Dutch Shell. Shell says that hydrogen is no more dangerous than gasoline.
Companies like Shell and Airbus chalk up the difficulties to the technology being in its infancy. They are planning out decades for new products.
“If you look back 100 years, we had horse carriages and steam engines,” said Mr. Law of Airbus. “There is no future fuel without pain.”