Hydrogen: the long-term panacea

Even though it's in scant evidence on the world's roads, hydrogen tops the list because it sits at the top of everyone's aspiration list. Hydrogen is the holy grail of the automotive world: a substance that's plentiful and emits nothing but steam and tiny quantities of nitrogen oxide in the process.

The downside: hydrogen is pretty uncooperative stuff. It isn't nearly as easy to muster into a tank as petroleum, petro-diesel or even other gases like LPG or natural gas.

BMW's Hydrogen 7 uses a version of the donor 7 Series model's V12 option, modified to run on hydrogen instead of petrol. It boasts a 0-100km/h sprint time of 9.5 seconds -- 50 per cent slower than its petrol counterpart. That's partly the fault of the 220kg of tank it needs to carry 8kg of gas, but they're working on it...

The fuel cell
Elsewhere, universities, governments and private sector agencies are pouring astronomical sums of cash into hydrogen fuel cell development.

A fuel cell is like a sophisticated battery in that it functions electrochemically. There are many different varieties, but the one of most interest to car makers is a version that works by converting hydrogen and oxygen into water. A by-product of the process is electricity.

Where batteries run flat, fuel cells don't. All they need is a steady (and modest) supply of hydrogen and oxygen going in to keep the water and the power coming out.

It's a business that can be made to sound much simpler than it actually is, so progress is slow in getting fuel cells viable for mass market use. Analysts and auto makers themselves admit it could be two decades or more before that happens in any big way. That said, Honda has embarked on a 200-unit rollout program, leasing its fuel-cell powered FCX Clarity to corporate and government clients; first in Japan and later in the US.

Where there's a will there's a way, and rest assured, the prospect of hydrogen power has given rise to a hell of a will. Be it via fuel cell, fuel tank or both, hydrogen will eventually be tamed.

Indeed, there's already one way in which it can be parlayed into automotive energy much more quickly and easily than the methods above. There's every possibility hydrogen will first gain in popularity as an additive to existing fuels.

Petrol, alcohol fuels and natural gas can be hydrogenated to boost performance and reduce particulate emissions and greenhouse gases. Advocates suggest that adding five per cent hydrogen to petrol can effect a 30-40 per cent drop in NOX emissions. (see hydrogen-fuel.org)

Beyond hydrogen, the industry is coming up with a fascinating cornucopia of interim solutions to the problems of global warming, diminishing oil supplies... and their own survival.

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