British consumers could spend an additional £3bn on energy bills this year as rising prices and the withdrawal of the cheapest deals take their toll.
Comparison website Energyhelpline.com predicts this could leave UK families out of pocket by an additional £118, making a serious dent in already stretched household budgets.
Although gas use has fallen in recent years and electricity use remains steady, providers are now taking their best value tariffs off the market.
Scottish Power and First Utility have both recently withdrawn their cheapest fixed-rate plans, narrowing the available options to energy customers looking to save money.
Scottish Power's Online Fixed Price Energy January 2014 plan - which cost an average of £1,052 a year respectively - is to be replaced by the Online Fixed Price Energy March 2014, which works out at £1,099.
First Utility, on the other hand, has no immediate plans to replace the iSave Fixed v3 plan, which cost an average of £1,040.
A similarly good value plan from EDF Energy is also being discontinued at the end of August.
Best fixed plans
The lowest fixed-rate plan is currently offered by OVO Energy, whose New Energy Fixed tariff costs £1,088, fixed for 12 months.
However, this also penalises customers who want to leave it before the end with £30 penalty fees for both gas and electricity.
So, if you're looking for a fixed deal without any penalties, then the best deal on offer is the new tariff from Scottish Power.
Consumers looking for the best deals will no longer find them on fixed-rate tariffs. Instead, discounted variable rates are the way to go.
Npower's Energy Online October 2013 currently costs £1,064 a year and comes with a guarantee the rate will remain at least 3% below the firm's standard rate until the end of October 2013.
Sainsbury's Energy's Online Variable September 2013 is the next cheapest, costing £1,068 and pegging the price 6% below their Clear and Simple tariff until 29 September 2013.
This is then followed by another npower tariff, Bill Saver Nov 2013, which costs £1,086 a year and guarantees prices will remain 5% below the standard rate for the next 14 months.
But while these deals currently offer the best rates, there are penalty fees to pay with them - meaning you will be charged £30 for leaving the contract early.