The current favourite is biofuels, typically made from renewable resources such as agricultural crops or waste. They are attractive not only because they are green, but because they can be blended into conventional petrol and used in today’s engines. Brazil has a huge market for ethanol made from domestic sugar cane. Car companies are equipping vehicles with flex-fuel capability, so they can run on either petrol or ethanol blends.
Another intriguing alternative to oil comes from natural gas. Gas-to-liquids (GTL) is the clunky name given to a set of fuels that can be blended into conventional diesel and used in today’s engines. They have the advantage of being super-clean, as well as boosting the potency of diesel fuel. Though they can be made from coal or biomass, the most likely option is natural gas.
The emerging combination of hydrogen fuel and fuel-cell engines [is another option]. Fuel cells are essentially big batteries that combine hydrogen fuel and oxygen from the air to make electricity that can power anything from a laptop to a home or a car. The hydrogen can be made from any primary energy source, be it fossil fuels or wind energy.
The beauty of this combination is that it produces no local emissions, and if the hydrogen is made from renewables or coal with carbon sequestration technology (which captures the carbon emissions from hydrocarbon use and stores them underground), no greenhouse gases either. That is why, says GM’s Mr Burns, fuel cells will finally take the automobile out of the environmental debate. And because hydrogen can be made anywhere by anybody, no OPEC would hold sway.