"Green" hydrogen competes with battery to power electric cars

By Thomas Struenkelnberg Jun 29, 2011, 3:06 GMT

Berlin - Visitors to any major automotive show these days can easily be forgiven for thinking that they could drive home in one of the electric cars on display. Most of the models are still at the prototype stage, but the manufacturers like people to think that they are the genuine production article.

Away from the hype and the bold design lines of these pioneering vehicles though, however, no one knows for sure what technology will prove to be most suitable for the regular electric car of the future.

Will it rely on batteries or on the more 'exotic' fuel of hydrogen to produce electricity via a fuel cell?

Some carmakers such as Germany's Daimler are pressing ahead while experts continue to argue over which drivetrain will prevail.

'Electric traction is going to accompany us into the future,' says industry expert Ferdinand Dudenhoeffer. He believes batteries and fuel cells will complement one another 'whereby the fuel cell will become increasingly significant in the long run.'

Dudenhoeffer does not expect the first commercially viable fuel cells to be available until 2025. He also predicts that Daimler, and US car giant General Motors will be at the forefront of future developments.

Things may move much more quickly than that, bearing in mind that Daimler has brought forward the series production of fuel cell-fitted cars by 12 months and plans to start making them in 2014.

The fuel cell produces electricity by combining hydrogen (the fuel) and oxygen (from air) via a catalyst such as platinum. It also overcomes one of the main obstacles on the way to a practicable electric car, namely the vehicle's limited range.

'Depending on the driving style and terrain, fuel-cell-powered cars can have a range of between 400 and 750 kilometres', says Andreas Opfermann, development chief at the Munich-based industrial gases and engineering corporation Linde.

Electric cars that rely entirely on batteries are seldom able to cover 150 or so kilometres before needing a recharge from mains electricity.

The lengthy refuelling process used to be a bugbear with fuel-cell cars but there have been improvements. 'It's now possible to carry out refuelling in the space of three minutes and that is comparable with the time needed for conventional vehicles', explains Opfermann.

The carbon footprint of fuel-cell cars improves considerably if the electricity used to produce the hydrogen fuel comes from clean, renewable sources. Until now hydrogen has been obtained largely from burning fossil fuels such as gas, leading to the output of carbon dioxide, which in turn is detrimental to the climate.

Linde aims to produce 'green' hydrogen from biogenic sources, namely organic material made from plants and animals (micro organisms). So-called biomass contains stored energy from living, or recently living organisms, such as wood, plants and other biodegradable materials. Linde is already operating a landmark hydrogen plant along these lines in the German town of Leuna.

If industrial-scale production of 'green' hydrogen at a commercially viable cost proves to be possible, Dudenhoeffer believes the fuel cell could be 'the solution for the next 5,000 years.'

His view is not shared by some other experts. Automotive analyst Frank Schwope who works for the North German Landesbank (NordLB), believes the fuel cell has only a minor role to play.

A number of manufacturers - such as BMW - have largely halted work on hydrogen-powered cars. Schwope believes the battery-driven electric car will establish itself alongside vehicles powered by combustion engines. In his opinion there is no room for a third technological solution.

Cost will remain a prohibitive factor for some time to come. Schwope estimates that a typical fuel-cell-powered car is likely to cost a five figure sum, more than the equivalent car fitted with a diesel or petrol engine.

Car specialist Stefan Bratzel points to estimates of between 15,000 and 20,000 euros (28,000 to 35,000 dollars) in additional costs per car, largely because of the precious platinum used as a metal catalyst.

Dudenhoeffer expects that by 2025 fuel-cell-powered cars off the showroom floor will cost about 20,000 to 25,000 dollars.

The lack of a comprehensive refuelling infrastructure is seen as another handicap to hydrogen in everyday use. At present Germany has about 30 hydrogen refuelling stations, seven of which are open to the general public and located in large urban areas such as Berlin, Hamburg and Munich.

Another eight are slated to come on stream at the beginning of 2012 and Daimler aims to join forces with Linde to establish another 20 additional facilities over the next three years. Each refuelling station will cost about 1 million euros.

Experts believe a network of an estimated 1,000 refuelling stations across the country is needed in order for the infrastructure to be on par with service stations offering fossil fuels, and establishing this would cost a staggering 1.5 to 2 billion euros.

Achieving this will take the best part of 20 years, believes Dudenhoeffer. Bratzel adds, 'I don't expect this infrastructure to be established over the next five to eight years.'

Three fuel-cell cars from Daimler have successfully toured the globe, but this notable achievement will not necessarily help the technology achieve a breakthrough.

So far Daimler has only committed itself to a small-scale production run of 200 cars with fuel-cell power - a tiny proportion of the 42 million cars currently in use on German roads.