A milder winter and energy efficiencies helped British Gas profits tumble by 26% in the first half of 2014.
Parent company Centrica predicts average bills will fall by around £90 this year because consumers are not using as much power.
However, industry regulator Ofgem has suggested that it sees power companies doubling their profit margins in the second half of the year.
They have already referred the Big Six energy companies to the competition authorities.
ITV News Correspondent Nina Nannar reports:
More top news
Dozens of email accounts are thought to have been compromised in a "determined and sustained" attempt to access Parliamentary accounts.
Speaking at Glastonbury Festival, the shadow chancellor said people who died in the Grenfell fire were "murdered by political decisions".
It's the largest Eid event in Europe, and today's figure smashed last year's record 88,000 people in attendance.