Talking of "spending less with an E7 tariff", I don't know how widespread it is, but in April my supplier (E.ON) changed its tariffs such that the 'best available E7 tariff' deal resulted in my saving as a result of having E7 (with no appreciable changes in total usage, or day/night usage patterns) falling to less than half of what it had been previously (the unlabelled {which I've only just noticed!} y-axis is £/year saving) ...
Kind Regards, John
Kind Regards, John