@judith thanks for that. Definitely useful to have reminders that may help others too.

Yes, I use GivEnergy api in WonderWatt and have used it in Octopus R&D. But not really used Octopus R&D so far.

Main issue for me is trying to make sure I only charge with cheap Agile slots but it may have to be a compromise based on how much I want to mess about manually for relatively small savings. So far I'm not seeing how to automate my particular case.

For now I'll stick with WonderWatt and see if savings + convenience make that the best option or whether there is something better.

@judith Which I feel means that with very similar cost per unit, it just remains to evaluate the ‘Faff Factor’ involved everyday if using Agile. Something tells me that if life is too short to stuff a mushroom, a similar attitude may prevail here! Regards, Toodles.

@Tim441, I'm on Octopus Agile for both import and export and I've gone a different route to avoid what @toodles rightly calls "faff factor". Probably key in my setup is bearing in mind a point I think @judith made in another thread about the amount of effort expended for relatively little gain (or, more importantly, avoiding it).

I have installed Home Assistant as the central point and got it talking to my inverter, my heat pump, my EV charger, Octopus' API and a number of other things besides. Having that as my foundation, I have implemented a number of what Home Assistant calls automations (rules to say if this then do that) and the key ones from your point of view are as follows:

• Since I have found the Agile pricing has historically always been expensive in the 4-7pm stretch - and likely onward until about 9pm - I have put in a rule to say that at 4pm the inverter should make sure the battery is not being charged from grid.
• If the Agile pricing goes negative, the battery should be told to start charging from the grid.
• I have the ability to set a couple of date/time values so I can tell the system manually that I'd like it to start or stop charging the battery at times of my choosing.
• If there is any sun at all, generally it'll fill the battery anyway, but the key is for us to have a full battery or thereabouts at 4pm. Therefore I have a rule saying that if the battery is less than 50% full at 2pm then charge from grid.
• Since the inverter can’t differentiate between EV charging load and any other form of load, I have a rule that when the charger is strutting its stuff the battery’s minimum state of charge should be 90% and reset to 10% when the EV charging stops. That avoids the EV being charged from the home battery.
• I also have a rule that stops the EV charger at 4pm. If I want to charge in peak period I have to restart it charging just after 4pm, but that’s a conscious decision.

These rules do not guarantee I’m extracting every last penny of maximisation. It does, however, give us 80-90% of the benefit for minimum effort. I do have other rules too but they’re just tinkering or unrelated topics.

@majordennisbloodnok always interesting to see other setups and approach. I'm slightly surprised that Agile export suits you but tbh have not checked prices much. What average have you got this summer?

I use Fixed export 15p 

I like the look of HA but main problem is my 2020 installed LG heat pump cannot be integrated afaik. The LG controller software is too old and cannot be upgraded. Possibly there are other ways to achieve it but I'm nervous of tinkering toooo much!

My Gen1 inverter max charge/discharge 2.6kwh is another limiting factor that prevents me maxing out cheap Agile slots

I too avoid charging battery 4-7pm and go a step further with thermostat setback 1 deg. I don't want the house to cool too much and think this will avoid quite a bit of peak imports. Partly needed again because of 2.6kwh max discharge rate with a 16kw ashp that might draw 5 or 6kwh.

My ev is not heavily used so I can normally schedule a Zappi charge when cheap. Typically at night sub 10p. So don't use solar as 15p export is usually better.

Filling the batteries using WonderWatt is pretty good and I could leave it to take care of it. So far spending a minute a day to tweak slots based on price, weather, SOC, pv solar expected, heat required etc etc. Without being too scientific! But accept I may not be saving a lot for the faff.

Overall happy with current state of play but hoping WonderWatt may improve options to reduce my manual tweaks. Or that I find a better alternative.

@majordennisbloodnok fwiw Octoprice comparison on exports for me. I doubt I can timeshift exports to improve.

16kw ashp, 8kw pv, 24kwh batteries, ev. Inverter charge/discharge at max 2.6kwh

Everyones usage, setup and ability to timeshift will mean its not one tariff that suits everyone. But so far I think Agile import and Fixed export is best for me.

1st Jan to 31st Aug 5608kwh @ ave 13.06p 

Switched to Octopus Agile from 23rd Mar (Tracker prior). 

Agile only is ave just 10.22p for 2458kwh from 23 Mar.

Tracker 1st Jan to 22nd Mar 2818kwh @ 16.15p

Usage includes EV, hot tub for a month, some imports at cheapest rates to fill batteries etc.

Imports ytd 5608kwh @ 13.06p = £732.31

Exports ytd 2432kwh @ 15p = £364.80

Net ytd cost = £367.51

Solar prod Jan-Aug = 5560kwh

Hopefully coming winter can keep under Tracker rates by good use of batteries as well as a bit of setback in peak periods

Ave import cost 8.08p in Aug for 331kwh inc Ashp for hot water and the EV

Export Aug 438kwh @ 15p

2023 imports were 8304kwh @ 22.2p on Tracker (not bad vs standard rates?)

Posted by: @tim441

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I'm slightly surprised that Agile export suits you but tbh have not checked prices much.

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Being frank, I've known for a while that I could get a better return on Octopus' fixed export. Agile used to suit us since the peaks can be quite high but that's become rather rarer now so fixed would probably make a better proposition. That said, we've been concentrating on using more of our own generation than maximising the export price, particularly now we've got an EV. It's less about timeshifting to get the best export price so much as minimising the cost to us of all the leccy we need to use overall.