Shock new figures have revealed that domestic energy prices have rocketed by 140% over the last nine years.
Official statistics from regulator Ofgem show the average dual-fuel bill for gas and electricity has increased from £590 per annum in 2004 to £1,420 this year.
The body said profits enjoyed by the UK’s “Big Six” suppliers – Centrica, EDF Energy, E.on, RWE npower, Scottish Power and SSE, which all recently announced inflation-busting price rises – increased from £1.25billion in 2011 to £1.6billion in 2012.
The situation has led to more than 130,000 people across the north and north-east being plunged into “fuel poverty” – the scenario in which 10% of household income is spent on energy bills.
Charities say winter is a worrying time for those on low incomes who live in poorly-insulated houses, and many are faced with the stark choice of eating or heating their homes.
Norman Kerr, director of Energy Action Scotland, said the consequences of rising electricity and gas bills were “misery, discomfort, ill health and debt”.
“Fuel poverty is an everyday reality for many low-income and vulnerable households,” he added.
“Many people ration their use of energy, perhaps by heating just one room or by avoiding using their cooker to make hot food.
“Where families with children cut heating and perhaps all use the one living room, this can have an adverse effect on children’s ability to concentrate on homework and studies.”
Mr Kerr said some older people could become isolated because they do not like to invite friends to their homes because they are cold and do not want to admit they are struggling.
“Living in a cold, damp environment can also exacerbate health problems,” he added. “At temperatures below 12C, blood tends to thicken, leading to an increase in blood pressure and increased risk of heart attack and stroke.
“Cold in the home can contribute to condensation dampness and mould growth, which can have a detrimental effect on some illnesses such as asthma.”
Citizens Advice Scotland chief executive, Margaret Lynch, said the charity dealt with people every day who were worried about paying their fuel bills.
“The challenges of fuel poverty are particularly acute in the north where temperatures are lower, and in areas where housing is older and less energy- efficient,” she added.
“It is not unusual for advisers to see people who are having to choose whether to turn on their heating or put breakfast on the table for their children.”
Energy firms have rejected the suggestion that subsidies for windfarms are inflating bills and claim the wholesale cost of energy, often imported to the UK, is to blame.
Some have started announcing plans to pass on savings to customers after the UK Government unveiled a package of measures to cut bills.
Scottish Gas said it would reduce bills by £53 in January, while SSE promised to pass on savings of about £50, and npower revealed it was planning a conditional price freeze until 2015.
Prime Minister David Cameron said the coalition would roll back the costs of green levies and charges and introduce more competition into the market to help reduce bills.
Audrey Gallacher, director of energy at Consumer Futures, said: “Relying on the levy changes by government to reduce homeowners’ bills by £50 is just not going far enough.”
Labour leader Ed Miliband has vowed to freeze prices for 20 months if he becomes prime minister but Angel Gurria, secretary-general of the Organisation for Economic Co-operation and Development, said that would drive away investors.
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