On the subject of tariffs, I have just been looking at the Octopus Agile tariff (historic half hour p/kWh prices available online) and the calculations based upon my electricity usage from Jan 1st this year to present day, show that I would have been better of by *£85 being on Agile (variable p/kWh and and 41.61p/day standing charge) than on my standard variable tariff (currently 25.92p/kWh and 47.4p/day standing charge). My average cost for the year to date is 30.12 p/kWh.
Agile peak prices of around 34p/kWh are between 4pm and 7pm, but can extend up to 8pm or 9pm and occasionally the peak price throughout much of the day (as the tariff is based upon grid demand, during cold snaps and in the winter months.)
Conclusion: If I manage to avoid using high use appliances during the peak evening periods and charging my car in the off peak times, (which occasionally go negative p/kWh - which means being paid to use electricity!) even assuming my *£85 saving will be eaten up by the November & December longer peak price periods, I may just try the agile tariff.