British households used 14% less energy in 2014, as average temperatures rose to record highs and drove down demand for heating, according to government statistics released on Thursday.

But bills continued to rise, with households paying £15 more for electricity on standard bills, which reached £592, an increase of 2.6% on 2013, and £23 more on gas bills, which rose 3.2% to £752.

The contrast between falling use and rising bills, even as wholesale gas prices also fell, is likely to raise fresh questions over the profits of energy companies, and fuel poverty.

Gas production increased, also helping a fall in imports, making the UK less dependent on foreign supplies. Gas supplies have become a geopolitical weapon, particularly for Vladimir Putin in Russia, and many proponents of shale gas argue that a new indigenous supply is needed to avoid the need for large tanker shipments from Qatar, which they say would have a larger carbon footprint than shale gas.

Energy produced from renewable sources in the UK rose to another record high, taking a 19% share of electricity generation. Along with a decrease in the amount of coal used – its share of power generation fell sharply, to 29%, from more than 36% in 2013 – this is likely to bode well for the UK’s greenhouse gas emissions targets.

Oil production from the North Sea sank to its lowest level since current reporting methods began. Net imports of petroleum products were 7.9m tonnes in 2014, the highest annual figure since 1984 during the miners’ strike, driven by the closure of Milford Haven refinery and the running down of several others.

Gas exports rose strongly, by 17%, while imports fell by 11%. Gas use for power generation increased by 3.6 percentage points owing to falls in wholesale prices.

Overall, the UK’s energy dependency stood at 46%.