Energy bills are set to ease for the next few months as the new Ofgem energy price cap came into effect today for England, Scotland and Wales.
Bills for electricity and gas are expected to average £1,568 a year for a typical household, a drop of £122 and taking it to the lowest point in two years.
However, these reductions are predicted to be followed by a rebound in prices in the run-up to winter, with leading analysts Cornwall Insight expecting a 10% increase in October from today's level.
It means household energy bills are forecast to reach £1,723 per year in October, up £155.
"Modest falls in summer look set to be wiped out by bigger rises in autumn when people will need to put the heating back on," said Adam Scorer, chief executive at charity National Energy Action.
"The cost of energy remains an unaffordable luxury that many of the poorest simply cannot afford."
According to BBC analysis of the price cap, it will mean those living in a flat or one-bed will see annual energy costs of around £1,148, while larger four-bedroom-plus houses will pay £2,182 on average.