Will hydrogen-powered buses cut urban pollution?

"That's why London is investing heavily in hydrogen, and spearheading this transport revolution is one of the city's most recognisable symbols. The first stop on the road to a hydrogen-based economy is being made by the red London bus. Capital-dwellers nd visitors might have seen one of the three hydrogen buses on the RV1 route between Covent Garden and the Tower of London. Save for stickers displaying its green credentials, a hydro-bus looks exactly like a regular single-decker. But listen carefully: it is barely louder than a milk float. Look closely and you'll notice its only emission is a plume of steam.

"Soon up to a dozen buses will be added as London spends tens of millions on its experimental fleet of "hydro-vehicles." If the test proves successful, London's bus fleet could switch to hydrogen in the next decade. By 2010, the hydro-fleet will have swollen to 70: we could also expect hydrogen-powered emergency vehicles, police cars and road sweepers...

"The appeal of hydrogen is easy to understand. It is the most abundant element on Earth, and its oxidation produces huge amounts of energy per unit mass. The hydro-buses use a process invented in 1839 by William Grove, a British lawyer and amateur physicist, in which hydrogen is combined with oxygen within a duel cell to generate a powerful electric current. The hydro-buses are quiet because the fuel cell, which is held in the roof, removes the need for an engine. The only exhaust is steam, because the hydrogen removes the need for the diesel engine.

"But the hydrogen molecules must first be extracted from another source, usually either water or a fossil fuel such as coal or gas. The cleanest way to make hydrogen is to electrolyse water using electricity generated from renewable sources; solar power has been used to power fuel-cell buses in Perth in Western Australia. But in London's case, "this means obtaining hydrogen from natural gas," says Mark Waatts, the mayor of London's advisor on energy, transport and air quality. The trouble is, he explains, that this process still produces carbon dioxide, "although it is about 30% less than the amount from the equivalent diesel engine." This also means the carbon dioxide can be released into the atmosphere miles from London.

"The use of hydrogen is being held down by price. It costs up to 10 times more to take a bus passenger one kilometer using hydrogen rather than diesel" (Sean Dodson. "Lighter route to a cleaner London." Guardian Weekly, Aug. 3, 2006: 21).

"...if you take veggie oil and process it slightly to remove the glycerin... you have a ready-to-go fuel for diesel engines. Whether you have a diesel pickup truck or a Mercedes, it'll run on this stripped down veggie oil without requiring any modification to the engine. Just tank up and go!

"Willie has been tanking up his tour buses with it for some time...

"The fule's average price is $1.79 a gallon, and while the major concentration of biodiesel pumps is in the Midwest, Nelson hopes to spread it from sea to shining sea...

"... biodiesel also is much better for the environment, it can be an economic boon for America's family farmers, and your exhaust fumes can smell like donuts!...

"Rep. Dennis Kucinich is preparing legislation to help develop this new biodiesel industry for America" (Jim Hightower. "BioWillie." Progressive Populist, March 15, 2005: 3).

"ExxonMobil's profits are up 44%, Royal Dutch/Shell up 42%, etc. According to the business pages, the biggest problem oil executives face is what to do with all their cash. So why give more tax breaks to the oil companies?" (Molly Ivins. "Energy policy so stupid, it's painful." Progressive Populist, June 1, 2005: 22).

"Meanwhile, what we are sticking with is soaring oil prices (ExxonMobil just reported the highest quarterly profit ever, $8.42 billion, by an American company)...

"Nor are the major oil companies spending their mammoth profits on exploration or field development--they're doing mega-mergers and stock buybacks... The Chinese and the Indians are now buying cars like mad, and the result is going to be an enormous supply crunch, sooner rather than later...

"Conservation is simply the cheapest and most effective way of addressing this problem. If you put a tax on carbon, it would move industry to wind or solar power. Wind power here in Texas is at the tipping point now--comparably priced. Our health, our environment, our economy and the globe itself would all benefit from a transition to renewable energy sources.

"And as Tom Friedman recently pointed out, it would do a lot for world peace, too: "By doing nothing to lower US oil consumption, we are financing both sides in the war on terrorism and strengthening the worst governments in the world. That is, we are financing the US military with our tax dollars and we are financing the jihadists--and the Saudi, Sudanese and Iranian mosques and charities that support them--through our gasoline purchases"" (Molly Ivins. "Dumb, Dumber, and Dumbest." Texas Observer, April 15, 2005: 14).