Switching to fixed tariff - Bringing length of cap into the equation

GQsm

Hi,
I am going to move to a fixed tariff, my annual dual fuel bill is approx 660

I have compared and these are the top 3 options for me along with the est price difference to what I pay now.

Scottish Power - Fixed till 31st Aug 09 - Est £9 dearer annually
Eon - Fixed till 31st Sept 09 - Est £44 dearer annually
British Gas - Fixed till 31st Dec 09 - Est £65 dearer annually

Obviously Scotish power is cheaper for now but I will be paying a new price by Sept 09. British Gas while dearer will see my price fixed until 2010.

I obviously know the correct choice depends on the Sept 09 price which we do not know but what are people's general thoughts on this. Do any mathematicians want to tell me what the price rise will have to be in Sep 09 to make it cheaper to go with the British Gas tariff fixed until 2010?
Throwing a few specualtive figures around will help me choose.

Thanks

KingCampo

If cheapest variable prices have risen above the fixed price by £15/month or more by 31 August 2009 means you'd be best off with B Gas. That's very likely to happen between now and then, by my reading of the market.

jb9

Looking at the BG website, they are no longer accepting applications for the Dec 09 fixed tariff

TonyNannini

I fixed gas and electricity with British Gas Until 2010 about 2 years ago. Is there anything cheaper ?
Tony