CONSUMERS are being urged to snap up the best capped fuel deals before more energy firms follow Npower’s lead last week and raise prices.

Npower, owned by German group RWE, is Britain’s fourth largest energy supplier and provides services to more than 6m UK homes. Last week it raised the cost of gas by 17.2% and electricity by 12.7%, the first rise in standard tariffs since the price falls last spring.

It will mean the average Npower dual-fuel tariff will now cost £1,047 a year, up from £908.

It had already raised its online tracker tariff by up to 17% the week before Christmas. British Gas parent Centrica also announced increases to its market tracker last month, lifting bills by 13% for gas and 15% for electricity.

Npower said that continuing wholesale price increases have left the energy industry facing a “difficult environment” in 2008, signalling that prices are set to rise across the board.

Experts said more firms are likely to follow Npower’s lead, including British Gas. Paul Green of price-comparison site energyhelpline.com said: “We predict all energy firms will have to increase their standard rates in the next eight weeks or so. The average energy price may hit the £1,000 mark this year.”

Wholesale one-year-forward prices for gas have risen 50% in the past year and are almost double the low recorded on February 21, 2006.

Meanwhile, electricity prices are up 44%, and 90% on February 2006 low.

Consumers worried about rising prices can fix their energy bills. Utility firms have become much more innovative in recent years, and many offer similar deals to mortgage lenders that fix your payments for a certain time, or put a cap on how much they can rise.

However, some energy suppliers have already started pulling their cheapest fixed products. Eon, which owns Powergen, and Scottish and Southern Energy withdrew their most competitive fixed tariffs last month.

Joe Malinowski of comparison site theenergyshop.com said: “Unless you act quickly you really will miss the boat.”

The cheapest deal is the British Gas Click Energy 4, costing about £740 a year for direct debit dual-fuel customers – £199 less than the supplier’s average standard deal. But it is variable and you will have to check the rate at least once a month to make sure you are still on the best deal as the price is subject to changes in the rising wholesale energy market.

For those who cannot be bothered to check rates, a good deal is offered by Scottish Power’s Online Price Fall tariff, which is capped until November. This costs an average £763 a year.

If British Gas raised it prices by 4% or more, the Click Energy 4 tariff would become £769 – £6 more expensive than the Scottish Power deal.