Many alternatives developed for petrol
Natural gas and biogas
Natural gas occurs in the crust of the earth, and mainly comprises methane.
Biogas is the result of anaerobic digestion, when bacteria degrade organic matter in the absence of oxygen. It can be recovered from landfills and sewage treatment plants, for instance.
Both can be used in cars in pressurised, or liquefied form. The containers are larger than a car’s ordinary petrol tank, and can withstand pressure.
Sweden has about 6,000 vehicles that run on natural gas or biogas. In all of Europe the figure is about 500,000. Most use natural gas.
There 75 buses in the Helsinki region that run on natural gas.
Finland’s only biogas car is owned by Erkki Kalmari in Laukkaa.
Natural gas costs about as much as diesel oil. It is more difficult to put a price tag on biogas.
Widespread use would require investments in both a network of filling stations and in the cars that use it.
Natural gas reduces carbon dioxide emissions by about 25%, and biogas cuts the emissions by more than 80%.
Ethanol
Ethanol is most frequently used in petrol mixtures. It cannot be used with diesel engines.
It can be manufactured from sugar plants and grain, or as a by-product of the wood processing industry.
It is possible to add about 10% ethanol to the petrol of ordinary cars. Larger amounts require a specially-structured fuel system.
So-called fuel-flexible vehicles can use any fuel from ordinary petrol to 85% ethanol.
Sweden has about 15,000 ethanol cars. There are none in Finland.
Ethanol itself is a renewable energy source. However, fossil fuel is sometimes consumed in the distillation process.
Biodiesel
Can be manufactured synthetically or from plant oil esters, which can be extracted from rapeseed, for instance.
The esters can be used in diesel engines, and can be mixed with diesel oil.
The synthetic fuel can be used as such. The plant oil-based product requires stronger gaskets.
It is used to some extent in Germany, Austria, and France.
The price is not yet competitive on the fuel market.
The esters are biodegradable.
Dimethyl ether (DME)
DME is a fuel that resembles liquefied gas.
Can be manufactured from either natural gas, or from coal or biomass, for instance.
Can be used in diesel engines, but requires an exceptional fuel system.
Volvo is especially interested in developing DME-based solutions.
Not yet in use, therefore its costs remain unknown.
Hydrogen
Extracted mainly from natural gas, but can also be produced from non-fossil material.
Cannot be used in ordinary internal combustion engines. Cars would require structural alterations.
Can also be used in the fuel cells of electric cars.
BMW and Ford have built prototypes of hydrogen-powered cars.
A few hundred cars powered by hydrogen fuel cells are in use around the world.
It is possible to make hydrogen cars completely emission-free.
Electric cars
The electricity that runs the car is stored in special batteries.
The battery can be charged from an ordinary electric outlet.
The cars can go for 70-80 kilometres with one charge.
The batteries weigh about 400 kilos. Lithium batteries are likely to offer a more lightweight option.
Finland has about 200 electric cars. The price of one is about EUR 20,000.
There are no emissions from driving an electric car, but the actual environmental impact depends on how the electricity is produced.
Hybrid cars
Hybrid cars have both an electric engine and an internal combustion engine.
Electricity is used for shorter distances at lower speeds, in the cities, while the regular engine is used for highway driving, for instance.
There is one hybrid car model on sale in Finland - the Toyota Prius.
There are only about 100 such cars in use in Finland, and about 250,000 worldwide.
Hybrid cars are still considerably more expensive than standard cars.
Helsingin Sanomat / First published in print 6.6.2005.
More on this subject:
 Eco-cars still a fairly rare sight on Finnish roads
In Stockholm, 2,500 cars run on ethanol
Helsingin Sanomat
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