My Octopus Agile &Go Tariff analysis website


Yep, sounds a plan.

The beauty of having options is choosing the one that bests suits you and your circumstances.

For me, i’m exporting waaaaay more than 50%… its closer to 75% as I have no battery or EV yet.

But what about this for a plan with your Powerwall?
Fill your battery up with free solar and then sell some of it back between 4pm and 6pm at 11p per unit. :wink:


The Agile tariff is now over 18 months old and I was looking back and the history of the pricing yesterday. Geek that I am!! :rofl:

So, what’s driving the price down?

  • More renewables? ie 24hr wind contribution? and more Solar?
  • Overall downward trend in wholesale pricing? (driven by low gas prices?)
  • Octopus getting a better handle on pricing versus demand versus profitability?

Or a combination of everything? :smiley:


Been a while since I posted some Agile prices… here’s last night.

5p per unit for around 6 hours straight from midnight onwards.

This is certainly a growing trend. :+1:



One-third of a penny per unit tonight!!


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.


This is where the code / app of the batteries / chargers needs to be better imho.

With Octopus publishing data via their API its upto the app owners to hook into this to allow charging when appropriate (ie when cheapest). They should be no need to ‘predict’ or hand crank charging times when the data is fully available each evening for the next day.

The Ohme charger for example does this.


The latest fruits of my coding labour is a new Twitter account (@energystatsuk) that tweets out and graphs the next days Octopus Agile tariff data each evening.

Its work in progress, so if anyone has any thoughts or comments please let me know.