I've just realised something weird - my leccy company, Scottish Power said that my useage was £100 or so a month and wanted me to pay more than that regularly 'to save up for the autumn and winter'.
Since I had a pre-pay put in a week ago, I have been using tumble dryer, washing machine etc if anything more than usual, and I still have £5 credit left from a £10 starter! So where does that 'you use £25 a week as a baseline throughout the year' come from?? Just shows doesn't it..