Energy nation

Oil

Status: Non-renewable

How was it formed?

Oil was formed millions of years ago. Dead organic material built up on ocean floors, riverbeds and swamps. It mixed with mud and sand. More sediment piled on top. The heat and pressure changed this layer into kerogen. Over time, kerogen breaks up into shorter, lighter molecules and is mostly carbon and hydrogen. If this mixture is liquid, it will turn into crude oil.

How is it used to generate electricity?

Oil is burned to heat water. This produces stream which pushes against the blades of turbines, causing them to spin. The turbines are connected to a generator, which creates electricity.

Where can you find it?

North Sea, but there are also small fields in south England.

Advantages and disadvantages of using oil to generate electricity

Advantages

  • Oil is easy to transport by pipeline or ship
  • Oil-fired power stations can be built anywhere there are good transport links and where there is a plentiful supply of cooling water
  • A large amount of electricity can be generated from one power station quickly

Disadvantages

  • Burning oil produces carbon dioxide, which contributes to the greenhouse effect
  • It also produces other emissions eg sulphur dioxide
  • Oil is not renewable. The world’s supply of oil is running out quickly
  • Using oil is very expensive compared to coal and gas

How many power stations in the UK?

2 (100MW and above).

The future?

Oil reserves should last until the middle of the 21st century.