The problem I see with agile tariffs, at least for me, is that you can’t completely predict when the cheapest periods will be. I charge both my Model S and Powerwall 2 on night rate electricity and am currently on the EDF Easy Online 18 month tariff which is 4.9p/kWh night (7 hours) and about 24.6p/kWh peak. These lowest and maximum rates are similar to your Octopus Agile real rates, but the high peak is much longer on the EDF tariff. Thos doesn’t bother me because my Powerwall 2 should supply all my Peak rate demand.
So my problem with the Octopus Agile tariff is that I set the night period on the Powerwall 2 and set the start of charge the on the Model S so that they only use the low night rate and I have 7 hours of that. Until we get smart Powerwall and Model S charging times that tie in with the agile tariffs I can’t accurately set the timers to be sure to use the cheapest rates.
I do have another problem with the Easy Online tariff, which required the installation of a Smart Meter, something I was rather reluctant to do, with good reason it seems. Until the smart meter was fitted a week ago, I wan’t using any peak rate electricity, according to both my old drum meter and the Powerwall PVOutput data. However, the smart meter is clocking up a steady demand of about 0.1kW all the time. That may not sound much but equates to over £150 per annum! Investigations are under way. Before you make observations on this problem, please read my detailed correspondence on the Tesla Motors Club Energy forum at
I am aware of potential sampling errors at low energy flows.