EDF Energy's latest tariff, Blue + Price Freeeeze March 2017, guarantees to freeze electricity and gas prices for the next four winters.
The deal is one of two four-winter fixes currently available, but at an annual £1,340 for dual fuel, it undercuts nPower's Price Protector March 2017 by £1 a year. Both deals carry no exit fees, meaning customers are free to ditch the deal if prices fall or better deals emerge.
EDF is also offering a shorter term fixed tariff, Blue + Price Promise 2015, which pledges to inform customers if rival suppliers launch a tariff that will save the typical household the equivalent of £1 a week.
Martin Lawrence, managing director at EDF Energy said: "The popularity of our previous Blue tariffs has shown us that customers like the option of a fixed-rate product. This enables them to budget more accurately, as many consumers are worried about the increasing cost of energy."
As energy bills continue to spiral, more consumers are opting for the security of a fixed rate. According to uSwitch.com, 77% of switchers now plump for fixed deals, up from 26% in January.
At the moment fixed rates compare well with the best standard tariffs. The cheapest variable deal - Spark Energy's Advance 2 - is currently £1,116, while the cheapest fix - First Utility's iSave Fixed v9 April - costs £1,170. The difference could be wiped out by a price rise of as little as 5%.
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Ann Robinson, director of consumer policy at uSwitch.com said: "While rumours of price hikes are never welcome, consumers can take some small comfort from the fact that suppliers are battling it out to offer the most competitive fixed price deals.
"Many of these are also ‘best buys' which means that consumers can enjoy the best of both worlds - a cheap price today, plus protection against price hikes tomorrow."