Energy giant SSE pocketed a 28% profits boost from UK households over the past year as they turned up their heating to keep out the bitter winter weather.

SSE’s retail operation made £410.1 million in the 12 months to March, compared with £321.6 million in the previous 12 months as gas consumption increased by a fifth.

Overall pre-tax profits rose by 6% from £1.34 billion to £1.41 billion.

But executive bonuses were slashed by 40% in the wake of a mis-selling scandal which last month saw the company fined £10.5 million for misleading customers about prices and savings that could be made by switching over.

Lord Smith of Kelvin, the chairman of SSE, apologised today over the practice. The firm said: “Companies don’t just have to earn profits; they have to earn profits in the right way.”

But the words will come as cold comfort to families after a year when SSE hit them with a 9% bill hike.

The energy giant said household consumption of gas over 2012/13 - which included a prolonged cold spell at the start of this year - went up 21%, with electricity use rising 5%. But its customer numbers in Britain and Ireland fell by 80,000 to 9.47 million.

SSE warned that more price rises were in the pipeline because it was facing additional costs of more than £80 per dual fuel customer in 2013/14.

It added: “Unless there is a sustained reduction in prices in wholesale gas and electricity markets, it is highly likely that these additional costs will eventually have to be reflected in higher prices for household customers.”

SSE said it intended to “resist this trend of higher costs for as long as possible to shield customers from the unwelcome impact of higher prices”.

The company said the rise in profits from households was as a result of the weather being colder in 11 of the 12 months of the year than it was in the previous year.

It said it was disappointed to have had to implement a price rise in October given that “energy affordability is a major societal issue”, blaming costs including wholesale energy price rises.

The company defended its profit margin as reasonable and sustainable, saying it “stands comparison to organisations that provide other every day essentials such as food retailers, telecoms companies and high street retailers”.

SSE, which trades as Southern Electric, Swalec and Scottish Hydro, announced the profits boost shortly after facing what Lord Smith described two of its biggest ever challenges since being formed in 1998.

In March, extreme snow falls and ice caused unprecedented damage to its electricity network in parts of western Scotland, with hundreds of staff drafted in to restore supplies.

The following month it was fined by Ofgem for mis-selling. It has launched a compensation fund for customers who lost out by joining SSE.

Lord Smith said: “Like everyone else associated with SSE I have no hesitation in apologising unequivocally for the breaches that occurred. But while the breaches were wrong, the response has clearly been right.”

He added that the overall performance of the company in the year allowed it to extend an unbroken record of annual increases in adjusted profit before tax.

In today’s announcement, SSE said its remuneration committee decided that “substantive criticism” over mis-selling had to be reflected in its annual bonus scheme.

“As a result, it concluded that the executive directors’ earned award should be reduced by 40% in total. This represents a fair response to the issues in one part of SSE’s retail division.”

It was the second consecutive deduction in the annual award due to sales-related issues in the energy business. The mis-selling scandal dates back to 2009.

Outgoing chief executive Ian Marchant, due to leave in June, has waived his annual bonus of £329,000, as well as a share payment from 2012. He missed out on this bonus for 2013.

However he will still benefit from a 2011 share award and a £10.4 million pension pot, paying out £420,000 a year from the age of 60.