Energy world

Energy sources: Oil

Status: Non-renewable

How was it formed?

Scientists are still not completely sure of the origins of oil. The leading theory suggests it formed millions of years ago, in places where dead organic material built up on the bottom of oceans, riverbeds or swamps, and was mixed with mud and sand. Over time, more sediment piled on top, and the resulting heat and pressure changed the organic layer into a dark and waxy substance known as kerogen.

The molecules in kerogen eventually break up into shorter and lighter molecules composed of mostly carbon and hydrogen atoms. Depending on how liquid or gaseous this mixture is, it will turn into either crude oil or natural gas

How is it used to generate electricity?

Oil is burned to heat water. This produces steam which pushes against the blades of turbines, causing them to spin. The turbines are connected to generators, which create 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 where 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?

The UK has two oil-fired power stations producing 100MW or more each. That means that each power station produces enough electricity to supply around 1,800,000 homes. Together these power stations supply 1.2 % of the UK’s energy needs.

How much does it cost to produce?

4.8p to 6p per kilowatt hour

What is the carbon cost?

580kg/mWh

The future?

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