The "big six" energy firms made an average profit margin of 20 per cent for energy generation in their last financial year, according to figures released by energy regulator Ofgem.
The results are likely to fuel further anger over rising gas and electricity bills.
The key figures included:
- Profits in the domestic supply business increased by 75 per cent
- Companies made on average £53 per customer each year
- Average profit margins increased from 2.8 per cent to 4.3 per cent in 2012
- The big six made an average profit margin of 20 per cent for energy generation in the last financial year
More top news
For the first time in its 34-year history, the editorial board of USA Today have taken a side in a presidential election race.
Thousands of vehicles have been confiscated by police forces because their drivers were either not insured or did not have a valid license.
Across all of the Help to Buy schemes, 185,000 homes were brought, including 150,000 properties to first time buyers.