The fuel cell is a reliable, sustainable and efficient source of energy. So far, it hasn't been economically viable, but a project in Surrey suggests things may be about to change.
A metal box the size of a sea container will arrive in Woking, Surrey, in the next few weeks. It may not have the dramatic silhouette of a wind turbine or the futuristic glint of a solar roof, but the technology inside it is being heralded as the most exciting development yet in environment-friendly power: the fuel cell.

Fuel cells convert hydrogen into power using chemistry instead of combustion, producing significantly less pollution than other fuel-driven generators. They operate almost silently and are more reliable than wind and solar devices because their output is constant and can be switched on and off at will.

Significantly, fuel cells produce as much thermal energy as electricity. "People lose sight of the fact that 70% of energy needs are thermal," says Allan Jones, energy services manager at Woking Borough Council, the man behind the Woking project (And it's coming to the UK, right).

Jones admits that the upfront costs are prohibitive at the moment, but the technology is advancing at such a rate that fuel cells could soon eclipse other sustainable power sources. "Fuel cells are where photovoltaics were five years ago," he says, "but they're more economical and beneficial." He compares the Woking project – which is costing £2810/kW output – with the first major photovoltaics scheme in the UK at the University of Northumbria in 1995, which cost £8850/kW. "The capital cost [of fuel cells] is higher at the moment, but the output is many, many times higher," he says.

High installation costs have so far prevented uptake in the UK. "I looked at putting a fuel cell combined heat and power [CHP] plant into the new Wellcome Wing at the Science Museum, but it was a touch too expensive," says Chris Twinn, associate director at engineer Arup. "They cost about twice as much as a normal CHP unit, but they look like a very useful future technology."

Costs are expected to plummet as the technology advances. For example, fuel cells have been developed to run on hydrogen-rich fuels such as methane, ethanol, butane and natural gas, to overcome the practical problems of producing and distributing volatile hydrogen. However, while pure hydrogen fuel cells are totally pollution-free, these other fuels will produce limited amounts of greenhouse gases.

Ironically, it is the Americans – the greatest polluters on earth and the villains of November's failed climate talks at The Hague – who are making most of the running on fuel cells, with President Clinton committing $100m (£70m) to research last October.

US car firms such as Ford are investing vast amounts in developing fuel cell-powered vehicles, and products are also being developed for buildings. IdaTech, a company based in Portland, Oregon, hopes to be the first to market a methanol-powered domestic unit that can be retrofitted to any home. "The system would be able to provide all the power required by a fairly typical US home," says IdaTech communications director Gordon Gregory.

Gregory expects the fridge-sized, 3 kW unit to cost $10 000 (£7000) when it goes on sale in two years' time, with running costs of about 10 cents (7p) per kW/hour – which is comparable with grid prices in much of North America. "Fuel cells will, we believe, be producing a significant amount of power worldwide in 10 years," says Gregory – but he admits "it's anybody's guess" exactly how much.

Jones is more optimistic. "I believe the hydrogen economy is the future, both for transport and stationary power," he says.

It is rocket science …
The principle of fuel cells was discovered by Sir William Grove as long ago as 1839, although the first successful device wasn't built until 1932. The technology took off in the 1950s when NASA developed fuel cells for its forthcoming manned space missions.

Despite optimism in the 1960s that fuel cells would solve the world's energy problems, a commercially viable version proved elusive. However, worries over fossil fuel supplies and increasingly tough environmental laws mean that there is renewed impetus to develop the technology, with experts predicting that cost-effective devices are just five years away.

… and it's coming to the UK
Woking Park leisure centre in Woking, Surrey, is to get the UK's first fuel cell. A 200 kW fuel cell CHP plant is being fitted to the centre as part of a demonstration project to showcase the technology.

The unit, which costs $900 000 (£630 000) plus a similar amount to install, is being supplied by US firm International Fuel Cells. It contains a reformer to turn natural gas into pure hydrogen, a stack of fuel cells and a converter to turn the DC power output into AC. It will generate 200 kW of electricity plus the equivalent of 223 kW in heat. Power will cost 6.5p a unit.

Low-grade hot water will supply the leisure centre's swimming pool and high-grade hot water will power the heating system. Woking hopes to get health and safety clearance to supply showers and drinkable water sources in the future.

The fuel cell, externally mounted with educational display panels explaining how it works, is being part-funded by the Department of Trade and Industry and the US Department of Defense. It is expected to be operational by August 2001, which will help Woking Borough Council reduce its exposure to the new climate change levy. Surplus power will be sold to local users.

Here's how fuel cells work
A fuel cell is like a giant battery, generating power from hydrogen-rich fuels via an electrochemical process rather than by burning. It converts hydrogen and oxygen into electricity, heat and water.

Each cell consists of an anode (negative electrode) and a cathode (positive electrode) separated by an electrolyte. Hydrogen is fed into the anode while oxygen is fed into the cathode. A catalyst splits the hydrogen molecules into protons and electrons. The protons are able to pass directly through the electrolyte but the electrons cannot: instead, they are diverted through an external circuit, generating an electric current.

The protons and electrons then recombine with the oxygen in the cathode, producing heat and water.