| Hydrogen-powered buses in action
With pledges to cut carbon dioxide emissions and a crisis over fossil fuel supply fast approaching, there is a pressing need in Europe to rethink the way economic growth is fuelled. Using hydrogen as a transport fuel is a vision of the future for many. But there are barriers to developing a hydrogen economy. Substantial investment in new technology is required, both in vehicles and in fuel infrastructure. The Ecological City Transport System (ECTOS) project, funded under the City of Tomorrow Key Action of the EU’s Fifth Framework Programme, has begun to address these barriers. By testing the performance of hydrogen fuel cell buses and a hydrogen filling station on the streets of Reykjavik, it provides some of the investment to take the technology a step closer to commercial reality.
|Passengers boarding one of the three Straeto hydrogen fuel cell buses in Reykjavik.|
© Iceland New Energy
Fuel cells generate electricity from the reaction between hydrogen and oxygen to make water. Instead of carbon dioxide and other pollutants, vehicles that use them emit nothing but water vapour. The downside is that it takes energy to make the hydrogen they need. Hydrogen can be made by electrolysis, where electricity is used to split water into oxygen and hydrogen. Then, overall carbon dioxide emissions depend on how that electricity is generated. In Iceland, where the national grid is entirely renewable, from hydro and geothermal energy, hydrogen offers the chance of a zero–emission fuel economy, unique in the world.
The ECTOS project began in 2001, led by Icelandic New Energy (INE), a seed company founded by the University of Iceland and Icelandic energy companies. There were ten other partners, some shareholders of INE, including the energy companies Shell Hydrogen and Norsk Hydro, the Icelandic transport company Straeto and the automotive giant DaimlerChrysler which has invested in manufacturing hydrogen-powered vehicles. The universities of Iceland and Stüttgart were also involved. INE has a vision of the entire Icelandic transport system totally converted to hydrogen fuel by 2050, including private cars and fishing boats. ECTOS is the first step towards making this happen.
|The ECTOS hydrogen bus cut away, showing the fuel cell (green) and hydrogen tanks (yellow) inside.|
© Iceland New Energy
An important innovation of ECTOS was to design and build a hydrogen refuelling station on a public petrol station forecourt. “This was a major undertaking,” says project coordinator Jon Bjorn Skulason. “It took two years to get it operational.” The refuelling point, opened in April 2003, consists of an electrolyser made by Norsk-Hydro. The hydrogen is compressed and stored in seven storage tanks before it passes through a dispenser into the hydrogen cylinders on top of the buses.
|A hydrogen bus ‘posing’ at Iceland’s Blue Lagoon.|
© Iceland New Energy
The buses arrived in Reykjavik six months later. They are part of an expanding fleet of 36 fuel cell buses in operation worldwide, many as part of another European project known as CUTE. They are prototypes – the fuel-cell-drive technology is being tested around the world, including in Beijing, China and Perth, Australia, to see how well it functions under real conditions. In Reykjavik, the three buses represent 4% of the city’s public bus fleet.
During the following two years, they clocked up 90 000 kilometres. The buses performed well, comparing favourably in power and acceleration with diesel vehicles. The cost of their service and maintenance was carefully monitored, for comparison with conventional buses. “At the moment, the operating costs are out of the range of commercial profitability,” explained Skulason, “but the technology will become cheaper as it is refined and mass-produced.” And there were very positive results. “The vehicles needed less maintenance than anyone expected,” he continued. “They were available for 80% of the time, which is extremely good.”
ECTOS carried out an environmental analysis of the hydrogen buses in operation to see how efficiently they used their fuel. Their efficiency over the whole fuel chain was not optimal. The buses were designed for durability, not fuel efficiency. Studies showed that efficiency could be improved using the same equipment, if the buses operated for six or seven days at a time, raising the demand for hydrogen so that the station could generate hydrogen continuously for several weeks at a time.
Technical lessons were learned about operating hydrogen transport and infrastructure. For example, the metal pipes used to carry hydrogen at the filling station were not ideal at first and fatigue was detected at weak spots. The material has now been refined. “The future hydrogen world will benefit very much from this kind of research,” claimed Skulason.
Just the ticket
Passengers travelling on the buses were consulted for their views on hydrogen as a fuel, in surveys carried out by the University of Iceland. Their response was overwhelmingly positive – 90% thought hydrogen was a good fuel, and people associated it with water and a clean environment.
|© Iceland New Energy|
The ECTOS project generated interest from all over the world, with television crews coming from as far away as Korea, China and America to film the buses in action. But what happens now? The European Commission strongly supports the development of cleaner vehicles, especially heavy-duty and public vehicles, and sees hydrogen buses as part of a solution to the problems of city air pollution and rising oil prices. The three ECTOS buses will be on the roads in Reykjavik for another 12 months, in continued trials as part of Hy-FLEET CUTE, a new European project that will run hydrogen buses in seven cities until 2009. After this, they will become obsolete. “What we have learnt from these trials will feed back to the companies developing the technology, both for filling stations and the vehicles themselves,” said Skulason. “We look forward to a new generation of vehicles which are better, cheaper and will bring us one step closer to the full commercialisation of hydrogen-powered vehicles.”