Is Hydrogen the fuel of the future?

Regardless of range, every vehicle needs fuel at some point. And here lies hydrogen's chicken-and-egg problem: fuel-cell vehicles will never sell in a big way until there is a viable network of service stations to fuel them. But no one is going to invest the capital required to create such a network until there is a fleet of thirsty hydrogen vehicles to provide a market.

Hydrogen pumps can and have been added to existing petrol stations, where at first glance they look much the same as conventional pumps. Because the hydrogen used is a compressed gas, filling the tank is not just a matter of placing a nozzle in the petrol-tank opening and letting gravity take care of the rest. Instead, a tight seal has to be established between the nozzle and car, and high-powered pumps have to force hydrogen through the nozzle until the desired pressure is reached. In practice, the current-generation hydrogen pumps are already easy and safe enough for an average consumer to use. But they do have to work perfectly if tanks are to be filled to full pressure; at present their performance is solid but variable.

A larger question facing car manufacturers is how rapidly the network of hydrogen-filling stations will spread. In the United States, for example, the number of hydrogen pumps is at present measured in dozens, and there seems to be little coordinated effort to change the situation. And until recently, things seemed much the same elsewhere.

That's why hydrogen proponents see so much significance in last year's agreements in Germany, which promise to break the chicken-and-egg deadlock. The car manufacturers have promised the cars, and NOW is pushing for a network of several hundred pumps throughout Germany within a few years, and as many as 1,000 by the end of the decade. That should be enough to provide broad coverage within the metropolitan areas and regular access along the highways. Bonhoff says that the consortium expects the price to be within the range of what energy companies would normally spend to maintain, upgrade and expand their petrol infrastructure over the same interval.

Charlie Freese, who heads the fuel-cell programme at General Motors, says that the hydrogen-infrastructure costs could be similarly manageable even in much larger countries such as the United States. In the early stages of a hydrogen-vehicle rollout, the Los Angeles basin could be well served with 50 hydrogen stations at a cost of roughly $200 million. Further down the line, some 11,000 stations might be needed to provide blanket coverage across the United States. "That's something you could do for roughly the cost of the Alaska pipeline," he says, referring to a proposed $35-billion project intended to carry natural gas from Alaska's North Slope to the North American market.

Hydrogen production

From a climate perspective, the main question facing hydrogen is where to get the gas in the first place. At present, the cheapest source is via a chemical reaction between steam and natural gas. But this process produces carbon dioxide, which means that the total greenhouse-gas production of a fuel-cell vehicle is not dramatically less than that of a conventional petrol vehicle. So the challenge is to derive hydrogen from carbon-free renewable sources.

Vattenfall, sees this as an opportunity and is building a facility in Hamburg that will use excess wind power to split water molecules and produce hydrogen for a fleet of 20 fuel-cell buses. Power companies tend to disperse extra wind turbines in various locations to compensate for the fact that wind is inherently unreliable. But those excess turbines will produce more electricity than the grid can handle if the wind blows in too many places at once. When that happens, turbines are shut down. Once the Hamburg facility comes on line, Vattenfall will instead fire up the electrolysis unit, tapping the excess power to make hydrogen and keeping the grid stable.

Cost is still an issue, says Oliver Weinmann, head of innovation management for Vattenfall in Germany. He says that the company will be able to produce hydrogen at €3–4 ($4–5.3) per kilogram, compared with €2 per kilogram for hydrogen produced from natural gas. But with Europe looking to expand its use of renewable energy over the coming decade, the growth potential is enormous, says Weinmann.

"It is not really a question of whether we can afford the hydrogen infrastructure," says Freese. "The question is whether we can afford not to have hydrogen infrastructure if we want to use renewables."

Adoption

Not everyone is persuaded by such arguments. Even if car manufacturers do get their fuel-cell vehicles to market by 2015, it will take years to establish a customer base, increase production and bring down costs. Few firms anticipate profitability on these vehicles until 2020 or even 2025. Meanwhile, they and the energy companies are also pushing biofuels and battery-powered electric cars, each of which would require its own distribution system. Building these transportation infrastructures simultaneously might not be possible.

These concerns are felt even within the car industry. Ford, for example, is confining its fuel-cell activities to long-term research, and has no current plans to market a commercial hydrogen vehicle. And BMW is hedging its bets with research into an otherwise conventional car whose internal combustion engine can burn petrol or hydrogen.

Some hydrogen advocates predict a multiple-niche scenario, in which battery vehicles are used in urban areas, whereas hydrogen pumps proliferate along the highways for long-distance travel. But perhaps the biggest mistake would be to assume that anybody in this game really knows what they are doing, says John Heywood, director of the Sloan Automotive Lab at the Massachusetts Institute of Technology in Cambridge.

Heywood says that the first round of vehicles will not be finished products so much as 'production prototypes' that allow companies to assess their performance — and the consumer response. Toyota followed this approach with its Prius hybrid car in 1997, and there's no reason to think that the process will be any faster for hydrogen or battery-powered vehicles. In either case, it could take three or more decades to revolutionize the global automobile fleet, says Heywood, and that's the kind of time frame that is guiding the car makers today.

"There are two paths, and they are going to invest in the electricity and the hydrogen pathway until it becomes clearer that one is significantly better than the other," he says. "Right now, we don't know the answer."