Higher tier: Substitute fuels
Biofuels are fuels made from biomass including wood, crops, plant materials and animal waste.
Examples include ethanol and biodiesel that can be used in vehicles as an alternative to petrol or diesel.
Ethanol is made from fermenting crops such as, corn and sugar cane to produce fuel that can be used in vehicles.
Biodiesel can be used in place of, or in addition to, standard diesel.
But not all cars are suitable for this fuel type.
In the UK, biodiesel is generally only available to mix with standard diesel.
Biodiesel is produced by combining vegetable oil or animal fat with an alcohol in a chemical process. The most popular sources of oil are:
- rapeseed;
- soybean;
- palm;
- coconut oil.
Small amounts of animal fat, from fish and animal-processing operations, are also used for biodiesel production.
The majority of biodiesel in the UK comes from recycled cooking oil.
Advantages of using biofuels
- They are a renewable source of energy if plants and crops are regrown.
- They reduce the emission of greenhouse gasses.
- They cause less pollution than petrol or diesel.
- They reduce our dependence on fossil fuels.
- They are easy to source - biofuels are made from many different sources such as manure, waste from crops, algae and plants grown specifically for the fuel.
- They reduce the need for fuel to be imported into a country as they can be produced from home-grown crops.
Disadvantages of using biofuels
- High cost of production increases the cost of motoring.
- Growing the same crop every year may deprive the soil of nutrients.
- Biofuels are produced from crops that need fertilizers to grow better - fertilizers can have harmful effects on the environment and may cause water pollution.
- Using fields to grow crops for biofuels means they are not being used to produce food – this could lead to food shortages or food price increases.
- The demand for biofuel crops means greater demand on rainforest land.
