Ofgem's report, the Retail Market Review, has shown that energy companies have on average made only 1.6 per cent profit on supplying customers since 2005, which compares favourably with other markets such as supermarkets and telecoms. 

Under the Warm Home Discount energy companies provide a huge amount of help and support for vulnerable customers especially the elderly and those on key benefits.

Switching energy company could save you money. There are several ways to switch. You can:

It is always a good idea to shop around for the best deal, and thousands of people switch energy companies every week, either looking to save money, better customer service or to take advantage of particular offers that suit their needs.  

There are a number of organisations that give advice on energy efficiency.

Britain now imports most of its energy. Companies have made big investments in recent years to improve the security of our energy supplies and ensure we always have enough to keep the lights on. 

A map of the locations of the UK's power stations can be found at Deloitte's website.

A number of coal, oil and nuclear power stations are expected to close between now and 2025.  They have a combined capacity of over 21 GW- about a quarter of our current generating capacity.

Power stations produce different amounts of electricity. For example, a 1 GW coal-fired power station will produce more electricity in a year than a 1 GW wind farm.

National Grid delivers gas to around 11 million homes, offices and factories.