Hydrogen power-These fuelish things-The fuel cell is enchanting politicians on both sides of the Atlantic. It is too soon, though, for them to dream of freedom from fossil fuels

WHERE in the world can you find hydrogen? At first blush, that might seem a ridiculous question: hydrogen, after all, is the commonest element in the universe.

The Economist

The problem is that it is rarely found in its free state on earth. If you want to get your hands on some hydrogen, you generally have to strip it away from carbon, as found in hydrocarbon fuels, or from oxygen, as found in water. Either way, energy is required to produce it. And that, in a nutshell, is the big drawback lurking behind all the recent hoopla surrounding the charms of hydrogen energy.

The hoopla began at the end of last year, when the European Commission unveiled a grand, euro2.1 billion ($2 billion) “hydrogen vision”. Romano Prodi, the commission’s president, even declared that he wanted to be remembered for only two things: the European Union’s eastward expansion, and hydrogen energy. Now, George Bush, America’s president, has produced his own $1.2 billion hydrogen plan (he even examined a hydrogen-powered car, and made sure he was photographed doing so). In speeches directed at the car industry in Detroit and, on February 10th, at the oil industry in Houston, Mr Bush and his team have been making the claim that the rise of the fuel cell will consign the internal-combustion engine to the dustbin of history. And if that were not enough, Democratic rivals in Congress—trying to keep up—have just unveiled their own hydrogen initiative.

Fuel cells are devices that work rather like batteries, converting chemical energy into electricity and heat. All fuel cells combine hydrogen with oxygen to produce power. These nifty power plants can be used to run anything from a mobile phone to an office complex. Their greatest attraction is that they can do all this without generating emissions any more harmful than water vapour.

The catch, of course, is that it is first necessary to find a source of hydrogen. If renewable energy is used to split water into hydrogen and oxygen by electrolysis, then the energy produced by a fuel cell is genuinely emission-free. But if energy from a hydrocarbon such as petrol or coal is used, there will still be some unwanted emissions. That applies even if the route taken is steam reformation, in which the hydrocarbon is reacted with water vapour to liberate the hydrogen in both, rather than being used to make electricity for the electrolysis of water.

The emissions from steam reformation, though, are less than those created when the same amount of hydrocarbon is burned in today’s combustion engines. This is because fuel cells produce electricity efficiently, without combustion. And, if techniques for capturing and “sequestering” the carbon dioxide produced by hydrocarbons are perfected, it would make hydrogen from fossil fuels a great deal cleaner still.

How the ghost of you clings

Europe and America do not see eye to eye on the question of how best to generate hydrogen. Europe is putting more emphasis on renewables; America, by contrast, is keen on the possibility of deriving hydrogen from fossil fuels.

At the moment, using renewables is an expensive way of generating hydrogen (see table). So why is Europe heading in this direction? Alessandro Ovi, one of Mr Prodi’s advisers, explains that Europe’s push for hydrogen is motivated largely by a desire to meet its commitments to cut greenhouse gases under the Kyoto treaty on global warming. Accordingly, the EU has adopted demanding targets for increasing the share of renewable energy to 22% of the region’s electricity supply by 2010, up from about half that today.

Such a target for renewable energy sounds pretty green, but there is a snag: wind and solar energy are intermittent, and unlike other commodities—be they bananas or natural gas—there is no good way to store electricity for later use. No way, that is, unless you use renewable energy to produce hydrogen, and store this instead. It can then be used when the power grid is facing peak demand and the price of energy thus increases. Dr Ovi thinks hydrogen could transform the economics of renewables and play an essential role in the EU’s clean-energy strategy.

Mr Bush’s plan pushes instead for hydrogen via fossil fuels, because greenery is not the only attraction of fuel cells. Mr Bush insists that hydrogen is a good way to bolster his country’s “energy independence” from Middle Eastern oil. Hydrogen can be made from America’s plentiful supplies of coal, as well as from locally produced biomass and renewable energy, says John Marburger, Mr Bush’s top science adviser. Thus, America’s reliance on oil from fickle foreign regimes will decline. That vision of energy independence through fossil hydrogen is also gaining popularity among the leadership in coal-rich but oil-starved China.

Does that mean the American approach is ungreen? Not necessarily. Even if fossil fuels were used to produce hydrogen without sequestration, fuel-cell-powered cars would still produce zero local emissions on roads. (Wags call this “drive here, pollute elsewhere”.) Further, hydrogen is likely to be produced by some green sources anyway: in the Pacific north-west, hydro-electric power is dirt cheap at night, and on the windswept Great Plains renewables or biomass may prove more economic than fossil fuels.

If America pursues its hydrogen vision by using fossil fuels with techniques such as sequestration, a technology Mr Bush has repeatedly applauded, its hydrogen embrace will indeed be greener than green. What is more, if Big Oil also gets behind hydrogen—as it is now starting to do thanks to the new push from the Texan oilman in the White House—the thorny question of where you can find hydrogen could one day become very simple to answer. Right at your corner petrol station.

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