Big-six energy supplier Npower has unveiled soaring profits after its customers fired up the heating in a colder 2012.
The company, which courted public and political anger with a 9% increase in energy tariffs in November, said profits were 25% higher at £390 million, compared with £313 million in 2011. It lost 70,000 customers last year but said its remaining 3.9 million used more energy in last year's freezing temperatures.
UK revenues increased 29% to 2.2 billion euro (£1.9 billion) following the price hike, but Npower, which is part of German energy giant RWE, said it was facing higher costs from Government energy-saving schemes and network fees.
Npower's profit haul comes after rivals British Gas and EDF also unveiled mammoth profits for 2012 amid prices hikes. British Gas owner Centrica revealed it made nearly £50 per household last year, while French-owned EDF posted a 7.5% hike in profits.
Npower said electricity generation increased 47% in 2012 compared with 2011 as new power station infrastructure, including its Pembroke gas plant, came online.
Its Tilbury power station in Essex, which was converted to run solely on biomass, boosted earnings and helped it to increase the amount of electricity generated through renewable sources, despite a fire in February last year.
Npower chief executive Paul Massara, said the group needed to be able to deliver a strong performance on the back of a major programme of investment in the UK.
He said: "We have invested billions in the UK, and although, at less than 5%, our profit margin remains significantly lower than other FTSE businesses, we are now beginning to see the benefits of that investment as our mix of different power station technologies provide a reliable, efficient energy supply."
RWE is involved in a number of major infrastructure projects in the UK, including the 2 billion euro (£1.7 billion) Gwynt y Mor wind farm off the coast of North Wales, in which it holds a 60% stake.
RWE delivered a better-than-expected 10% hike in profits to 6.4 billion euro (£5.5 billion), on revenues of 53.2 billion euro (£45.8 billion). But it warned it faced challenges from structural changes in the German energy market.