1.4 Summary of typical USES OF ENERGY

Energy for Transport

Non-renewable fuels like petrol, diesel or heavy fuel oil are all derived from the fossil fuel oil and are burned directly in internal combustion engines e.g. in cars, lorries, diesel locomotives, ships etc.

Coal was once used extensively to fire steam locomotives, but these have completely replaced by diesel and electric traction in most countries.

Although electric traction is 'greener', much of the electricity used in trains or cars is still generated from burning coal or oil. It would be much better if the electricity was all produced from renewable energy sources.

However, it is now possible to make renewable biofuels that can be used directly in motor vehicles or using a mixture of biofuel and petrol, though only the biofuel component is renewable.

Express mainline trains and local electric trams is the direction we should be heading.

Energy for heating and lighting

Historically most homes and factories would be heated from non-renewable energy sources like coal and some domestic heating from wood.

Many homes in Europe are now centrally heated from natural gas or oil (e.g. the UK uses gas directly from the North Sea gas fields or piped gas from Norway).

The gas (mainly methane, CH₄) is burned in open fires or boilers to make hot water for pumping round the house, office or factory in central heating system. Oil is burned in special boilers - the most efficient being the more modern condensing types which are more efficient - higher % of input energy converted to useful thermal energy to heat your home.

You can use solar panels to heat up water - pipes with a dark matt surface can be used to absorb the Sun's infrared radiation (thermal radiation) increasing the thermal energy store of the water. It can be piped to a hot water storage tank or through radiators in the house.

Wood stoves are growing in popularity and wood can be considered renewable - but the smoke is quite polluting!

Electric heaters are obviously cleaner for cooking and heating and night storage heaters offer efficiency for the consumer, but, its still a matter of how the electricity is generated, still mainly from non-renewables sources BUT increasingly less so.

Storage heaters are good by using cheaper off-peak electricity, but unless the electricity comes from non-renewable sources, its only a partial answer.

Solar water heaters capture sunlight energy (infrared radiation) directly to heat up water that can be pumped to a storage tank or radiators.

A geothermal energy source uses either hot water pumped from deep underground to the surface OR using a heat pump system which is rather like a refrigerator working in reverse.

Electricity is needed for heating and lighting in homes, shops and many work premises.

Electrical energy for industry

Huge amounts of (mainly) electrical energy are needed to power factory production lines and industrial chemical plants.

Very little can be manufactured without a supply of electrical energy to run machines and provide electric lighting for all types of industry.

Most industrial usage of electricity is derived from large scale power line distribution - pylons on the skyline!

In the UK it is referred to as the National Grid System

See The 'National Grid' power supply, environmental issues, use of transformers