Gareth Huw Davies

Environment Blog / Green Technology

The (carbon-neutral) view from the Tower Hill omnibus

Hydrogen buses which emit only water will start services in London later this month (December 2010) – reports PA.. The eight buses, using the latest hydrogen fuel cell technology,  will run on route RV1 from the Tower of London to Covent Garden. Their maintenance facility in East London has a hydrogen refuelling station.

London mayor Boris Johnson said: “These buses are a marvel of hydrogen technology, emitting only water rather than belching out harmful pollutants.” The hydrogen buses are jointly funded by Transport for London, the Department of Energy and Climate Change and the European Union via the Clean Hydrogen in Cities project.

In 2006 I travelled on the prototype. This is my story.

There is a precedent for bus routes having a wider meaning in London.  So just as the Clapham omnibus, and its right-thinking passenger, has entered the language as a measure of common sense, could the more prosaically named RV1 route, between Covent Garden and Tower Hill, come to represent the defining place in the switch to clean public transport?

We set off down the Strand aboard a freshly burnished Mercedes Citaro bus , the impeccably-coutured Sultan Dar at the wheel. Bystanders stand no risk of the asphyxiation.  Issuing from that complicated paraphernalia on the roof was nothing more noxious than water vapour. This, according to Transport for London (Tfl), makes it one of the most environment- sparing buses in the world. But what did the passengers think?

Sylvie Bodeux and her partner Jean Yves.  are from France. They travel by ultra-swift TGV and live in Lyon, a public transport showpiece,, with smart new trams,, trolleys, automatic underground trains and bikes loaned free to commuters.  Can London even hope to compare?

At first Jean Yves , who doesn’t speak English, having caught the word “hydrogen”, embarks on some understandable word association leading to “explosif” and “dangereux”. I pass on my briefing from Tfl, that there is no danger whatsoever to passengers from the hydrogen carried in tanks on the roof, although as a precaution they don’t use spark-causing tools back to the depot,   he offered some diplomatic “Yes of course, a very good thing” endorsement. Daughters.  Lucie and Lise seemed more impressed by the London Eye as we passed over Waterloo Bridge.

Sylvie, — as an English teacher she is clearly caught our humour — saw another problem: ”Ah, but you are going to lose the smog and that image of London that we foreigners so admire.”

London is one of Nine European cities which have been trialling the specially built Mercedes fuel cell buses since 2003, in the largest such project in the world.  The project is backed by 40 organisations, including manufacturers, operating companies and universities, backed by the European Union and, in the UK, the Energy Saving Trust, supported by the Department transport. They cities were chosen to represent a good mix of topography, road congestion, and climate.

Proponents believe fuel cell buses could help reduce city air pollution, and street level noise as well as contributing to cuts in greenhouse gas emissions .  The buses are being monitored to see how they perform and how they compare with conventional buses running on the same routes.

Passenger Dennis Jorg listened with interest to the list of virtues which transport for London transport is of claiming for these vehicles — they include a top decibel level 68, of which means we don’t have to shout.

But, as a London resident he has a financial stake here, and he, sees a snag. “In the long-run they may save the environment but we have to consider the cost. Do they break down more often, and do they cost more to repair?”

He doesn’t know the half of it.  These buses cost roughly six times the equivalent diesel bus; and the manufacturers provide a dedicated unit on permanent standby, to ensure they don’t have embarrassing public breakdowns, that would impress a Formula One team.

Praise was unstinting, however, from German tourists Mrs Riffel and her son. “It matters to us as tourists, if they city is polluted,” said she.  “Yes, we welcome this,” said he. “I’m impresssed by this sort of technology and happy that it’s starting to be used, even on a small-scale.”

I showed them the promotion leaflet, which manages to explain the fuel cell process even to me, who has struggled to understand how the internal combustion engine works, after all those years,.  As hydrogen gas flows from the roof cylinders into a fuel cell, it combines with oxygen and is converted into water. This process produces electricity, which drives the vehicle. The only emission from a fuel cell bus is water, which forms a vapour cloud as it leaves the exhaust.

By now  the debonair Mr Dar was steering the bus over Tower Bridge. A few minutes later,, and bang on timetable, he brought us to the final stop into a dingy backstreet which was not the right place to show off such a smart piece of technology.

He knows as much about this vehicle’ s performance as anyone.

“I drive this bus five days a week, throughout the year.  London streets are very polluted and I think this is a brilliant idea.”  So do many others, it seems.  “A lot of people are interested in this bus.  They see it on TV and they travel from as far away as Cornwall and Scotland to travel on it.

“It is just like a normal bus.  It does break down, but no more than any of the other vehicle.” And to drive? ” It feels just like a normal bus. If the driver didn’t know, he could hardly tell the difference, except that it is a very quiet vehicle.

Does that cause problems to other road users?  “It might where it’s a very quiet crowded , noisy road.  So you have to be extra careful. But it is not a problem.” And even if pedestrians and other road users don’t hear the bus so well, they can scarcely miss it, with its six tanks piled on the roof, and emblazoned with promotional slogans .

What Tfl’s enthusiastic flyer also does not explain is that it can only last 125 miles, at a Clarkson dersion-earning top speed of 50 mph — not that that matters much in the clogged streets of London — before they have to send it off, some time in the middle of the afternoon, to a special refueling station in Hornchurch.  Meanwhile the stalwart, standard London bus will grind valiantly on, from dawn until past midnight, without returning to the garage.

I put it to these points to Mike Weston, operations director for London Buses. This was a trial, he explained, and the costs incurred by three specialist buses had no real meaning.  Undoubtedly they would come down as hydrogen was more widely used, and the size of the fleet increased.

And although he acknowledged that the vehicles received luxury mechanical pampering, they were no more prone to break down than other vehicles.  In the long term it might turn out that fuel cell buses failed less often, because they had fewer moving parts. Some problems, for example , were already solved by a man coming out with a computer.

” At the outset we were a little sceptical about these buses’ reliability. We started them off on another route, complementing existing buses. They proved so dependable that we switched them to RV1, as part of the normal timetable.” As for their daily range, Mercedes asked to deliver a new demonstration bus, which it is hoped will address that issue.

Hydrogen can be produced in a number of different ways. The London buses receive theirs from the least environmentally friendly process, (steam methane reforming method) from natural gas , which is then transported in tankers to the Hornchurch refuelling station.  Weston said, once again useful comparison was being made to much greener processes, such as in Barcelona’s which involves the splitting of water, using solar power, into hydrogen and oxygen (electrolysis).

He foresees large numbers of hydrogen buses running in London, but probably not another 10 or 15 years after a slow but steady take-up of the technology.  A more immediate solution for London might be the hybrid bus, powered by diesel and battery, currently on trial in Outer London.

London’s Deputy Mayor Nicky Gavron, described the experiment so far as “more than promising”, with a “very positive” response from the public. She said a further 10 hydrogen-fuelled buses were being procured.

“Anybody riding those buses must now see hydrogen as part of the answer to pollution and energy-use in the capital.  We want low carbon transport in London as quickly as possible, and hydrogen is going to be a key to that because in terms of carbon emissions ultimately this is the Holy Grail.”