Households in England and Wales cut their energy use by a quarter between 2005 and 2011 as prices soared, government figures show.
The sharp fall was probably caused by a mix of efficiency measures and environmental awareness, as well as steep price rises, the Office for National Statistics (ONS) said.
Households have faced steep price increases in recent years as wages have remained frozen, squeezing budgets. Average bills have risen by 28% in the last three years, industry regulator Ofgem said.
The ONS figures showed that average energy consumption in England and Wales fell from 26.2 megawatt hours (mWh) in 2005 to 19.7 mWh in 2011.
Energy use varied widely between regions with the East Midlands the biggest consumer at 27.5 mWh a year. Regions with the biggest consumption also had the highest use of Economy 7 electricity which gives cheaper prices at night but the ONS said this only partly explained the disparity.
Wales and South West England were on average the lowest users of energy, each using just over 16 mWh a year. Regional differences fell by 35% in the period covered, possibly because the highest consumers had the biggest incentive to cut back, the ONS said.
In January the government launched its flagship Green Deal scheme, designed to encourage households to make energy improvements. The scheme lets homeowners borrow money for improvements such as a new boiler or wall insulation and pay the loan back as part of their fuel bills.
But the Green Deal has been beset by technical problems and takeup has been low. It also launched the Energy Company Obligation, a companion programme for low-income households requiring energy companies to help make homes more energy efficient