IMI Magazine

IMI Magazine

Cover Feature - Hydrogen to save the planet?

Fifteen, perhaps even ten years ago, what worried most people was not global warming, but how long the oil reserves would last. Some comfort was drawn from the fact that the answer was around 40 years - or rather, that it had been around 40 years for some time, because new discoveries were being added to the proven reserves at about the same rate as oil was being exracted. The best informed estimates were that the oil would last, in practical quantities, until around 2050. Beyond that, increasing scarcity would drive up the price to the point where alternatives would become economic.

Then the warnings began to sound. It was suggested, tentatively at first, that the delicate balance of atmospheric heating and cooling effects which maintain a tolerable earth-surface environment was being upset. Like so many balances, it seemed to need only a small extra load on one end to cause a permanent shift. For a time, our main anxiety was about the effect of various chlorine-based chemicals, the infamous CFCs, on the ozone layer. Concern for the effect of CO2 came a little later.

It was difficult to accept at first. Each of us eats fuel in the form of carbohydrates, combines it with oxygen to turn it into energy, and breathes out an exhaust in the form of CO2 and water vapour. Conventional vehicles with internal combustion engines do much the same thing, except that their fuel is hydrocarbon, which is likewise a combination of hydrogen and carbon atoms but arranged in a different way.

Yes, we were deeply concerned about toxic vehicle emissions - carbon monoxide, unburned hydrocarbons and oxides of nitrogen - but until around 1990 we wrote-off the accompanying CO2 emissions as “harmless”. Now, it seems, they may pose the biggest threat of all - the threat of significant climate change which will affect the way we all live, and reduce the area within which conditions are actually liveable in any normal sense.

In fact we have arrived at a point where the burning of the remaining oil reserves, within whatever timescale, may tip the atmospheric balance beyond recall. Our problem with carbon or hydrocarbon “fossil” fuel - petrol and diesel derived from crude oil, or indeed coal or natural gas - is that when we burn it, we are burning what nature happened to set in store during one particular period, tens of millions of years ago. It is not only that nature isn’t making it any more.

It seems increasingly likely that nature’s laying-down of coal, oil and gas deposits removed a massive amount of carbon from the eco-system and helped create the environment in which we now thrive - except that we are busy extracting the carbon and throwing it back into the atmosphere.  

We in the motor industry may argue that we contribute less than a quarter of all man-made CO2 emissions, yet we seem to attract most of the adverse attention. Certainly it is not fair. Week in, week out, my central heating boiler certainly emits more CO2 than my frugal Honda Jazz, driven only when it needs to be (and certainly not down to the shops). Yet I am told I should use public transport rather than my car, while nobody suggests I should abandon my boiler in favour of a district heating scheme (the chance would be a fine thing!).

The environmental sins of “dirty” industry are huge. But none of this matters. As the man in the street would say, Something Needs To Be Done About It. He leaves to others the question of what that something may be, and how it may be achieved.

You will find enthusiasts for bio-fuel, arguing that using fuel derived from vegetation means that we remain in the short-term carbon cycle and do not emit “fossil” CO2. They are right, but they ignore the daunting economics of bio-fuel and the fact that we can never hope to grow enough vegetation to produce sufficient of the stuff to keep the world on the move. Today’s users of bio-fuel may feel justifiably virtuous, but if we all tried to do it the system would fall apart under the strain.

They have a point none the less. We tend to overlook the fact that fuel - any fuel - is simply a convenient way of storing energy until we need it. The particular problem with vehicles is that their fuel needs to come in a form which enables sufficient energy for practical purposes to be stored on board. “For practical purposes” has long been tacitly accepted to mean a range of getting on for 300 miles, and even then with the added proviso that refuelling for the next 300 miles should be quick and convenient. This is where the pure electric car, about which we have heard less and less recently, has always fallen down. Regarded (as it should be) as fuel, a fully charged traction battery has an appalling energy density and a very high cost. The only real options for a road vehicle are a liquid fuel, or a highly compressed gas.

The options are extremely limited. Any practical liquid fuel contains carbon, which takes us back to square one, although it should be said that some of the possible liquids, notably the alcohols, contain less carbon than our familiar hydrocarbons, petrol and diesel. Even the gases contain carbon - the lighter they are, the less they contain. The natural gas (methane) molecule consists of a single carbon atom and four hydrogen atoms. The exception to the rule, the only fuel that is completely carbon-free, is hydrogen.

But hydrogen is not an end in itself, merely the means to an end. If we want to remain mobile in the long term, we need a fuel which will store energy from “renewable” resources - solar, tidal, wind, geothermal, hydro or whatever. And whichever fuel we decide to use must operate as part of a sustainable cycle which does not involve any permanent upset of our environment. It seems there is no way in which we can achieve this with any carbon compound, in the volumes now called for, without eventually swamping our eco-system. That is why hydrogen is the front-runner.

All that is certain for the moment is that the laboratories of the world are working on the alternatives. Somebody may yet synthesise a carbon-free molecule which enables hydrogen to be carried on board a vehicle in convenient liquid form, without any adverse effect on the environment. Or they may genetically modify a plant to absorb hitherto undreamed-of amounts of CO2. Or they may breed a species of bug which eats slurry and breathes out hydrogen. Or …The list of possibilities is long. For the moment, the likelihood seems to be that in the long term, we shall in some way be dependent on hydrogen as our principal fuel, and that we shall need to produce the hydrogen from renewable resources. That will certainly mean that fuel will become very expensive by today’s standards, even in Europe, and much more so in the US.

Here, at least, government fiscal policy has accustomed us to expensive fuel, which in turn has encouraged us to make our vehicles more economical. In the final analysis, it will certainly mean that we don’t drive so much, that we don’t travel by air so much, and that we generally organise our lives in a much more energy-efficient manner. Whether it means we shall have fewer vehicles is less certain. It is most likely that most households will still want their own car - though they will certainly drive it less, and more thoughtfully. Either that, or we shall see the inexorable rise of sea levels.

The billion dollar questionCar manufacturers are in the business of making money, not saving the planet, is the blunt message from two industry bosses.

Nissan’s Carlos Ghosn told the US National Automotive Dealers’ conference last month: “They (hybrid cars) make a nice story, but they’re not a good business story yet because the value is lower than the costs.”

As for vehicles powered purely on hydrogen, Ghosn said: “The cost to build one fuel cell car is about $800,000. Do the maths and you figure out that we have to reduce the cost of that car by more than 95 per cent in order to gain widespread marketplace acceptance.”

Dr Bernd Pischetsrieder, chairman of Volkswagen, has been equally forthright, commenting: “We are not interested in making cars which don’t make money.” While acknowledging that the day would come when Volkswagen offered hybrid cars, he said consumer preferences increasingly point to cheaper cars rather than those which are kinder to the environment.

That said, Ford plans to launch four petrol-electric hybrid models over the next three years following the success of its Escape Hybrid sport utility vehicle. Sales of Escape, which uses Toyota technology, grew by 9.4 per cent in North America last year.

Meanwhile, General Motors has committed $1bn into fuel cell research in a bid to produce a commercially viable hydrogen car by 2010. Larry Burns, head of the company’s R&D division, says that hydrogen already being produced could power a third of the world’s 750m cars, but recognises that this will only become viable through economy of scale if the switch to hydrogen is rapid.

Green for go?A  colour-coded environment label for all new cars will appear in UK car showrooms from July this year. It's intended to help car buyers assess the climate change impacts of different cars.

The new label - introduced years ahead of likely EU legislation - is the result of a voluntary agreement by car makers following discussions with environment groups and other road transport 'stakeholders' under the auspices of the Low Carbon Vehicle Partnership (LowCVP).

The gradations on the label will reflect CO2 bandings used for vehicle excise duty  to reinforce the message 'lower carbon emissions equals lower road tax'. Commented SMMT chief executive Christopher Macgowan: “By introducing this voluntary label the motor industry has shown its commitment to giving its customers clearer information on environmental performance.”

Edmund King, executive director of the RAC Foundation, said: “Motorists considering buying a new car will be able to see at a glance how green, clean and lean their potential new purchase is. Drivers on lower incomes spend 24% of their household budget on motoring so clear knowledge of fuel efficiency is essential.”