Fuels have been a quintessential part of world's energy resources since the turn of the 20th Century.

Our current reliance on fossil fuels is cause of concern to environmentalists and scientists alike, as the heavily polluting source of energy is non-renewable and will run out in the recent future.  Even though they are formed naturally by the compression of decayed animals and plants under high temperature and pressure underground, the process of formation takes place over millions of years.  As a result of this time period, fossil fuels can be classed as non-renewable.  To replace fossil fuels as the leading energy producer there are various other energy resources that could be used.  The largest energy producer apart from fossil fuels is nuclear power, however this is still non-renewable, and not cost effective. Scientists have also been heavily involved in the development of efficient windmills, which are expected to provide over 10% of the UK’s energy needs in the near future.  The power of the wind will last forever, so this form of energy is renewable, however the initial costs of the windmills are high, and they can be noisy and are described as eyesores by local residents.  Hydroelectricity is a renewable source of energy that uses the power of running water to turn turbines that are connected to a generator, creating electricity.  This too does have its disadvantages as dams are expensive to build and can cause the flooding of valleys in which small settlements may have to be relocated and agricultural land may be lost. Solar Power is an alternative form of energy that is increasing in popularity, but it is unreliable especially in places with a climate such as the UK, as there are low sunlight levels.  Geothermal Energy has proved to be very successful in countries such as Iceland, where there is a large amount of volcanic activity underneath the surface of the earth.

Scientists, in an attempt to find new energy sources have attempted to improve and develop new fuels.