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
More than 11,000 BHS workers will be told they face redundancy consultation today.
Divisions among MPs and party supporters have intensified in recent weeks amid an increasingly fraught leadership battle.
Stephen Port, 41, is already accused of drugging and murdering four men he met on gay websites before dumping their bodies near a church.