Octopus Flux

Korah

Hi - any chance we could have the option to optimise charging and exporting aligned to the octopus flux rates? Right now, I'd love for it to charge what it needs during the off-peak and then sell any excess during the peak. And in the lead up to peak, top up the battery in the normal rate, to ensure there is enough to cover during peak.

However, what I have noticed is that it doesn't charge enough and is using some electricity during peak.

admin

Korah Octopus Flux rates are fixed periods, right?

So you could easily configure your custom schedules with relevant conditions under the Schedules section. https://app.wonderwatt.com/schedules

Eg.

Offpeak charge schedule from 02:00-05:00
Pre-peak Top up schedule 14:00-15:59
Export schedule: 16:00-19:00

Korah

Brilliant. I didn't realise you could add more than the default 2 schedules. Thanks!

Do you read the daily load to adjust when and how much to charge?

admin

Korah If you toggle on Smart Charging we do indeed calculate it based on the average usage you have specified as well as take into account solar PV yield for your system and location.

RichardB

@Korah I think what you are describing is what I've just setup

MarkyMark

I am just trying to do exactly the same thing for charging so that I have enough battery to cover the high session. For your 'charge to 35%' schedule did you just set 'charge at least:' to 35%?

admin

MarkyMark Looks like that is a Smart charge, but it needn't be.

The 35% load up pre peak could be a straightforward fixed charge like so:

MarkyMark

admin Not doing quite what I thought. The WW screen is:

but that has set growatt as:

I wanted the afternoon charge to only take the battery to 50% SoC, if needed, to cover the 1600-1900 peak time, but is currently charging even though it is at 85%. The Growatt/Shineapp screen is showing a target of 89%.

nbullus

Just be careful with your export at peak times. Once you've exported what you wanted, it won't revert back to ECO immediately until the scheduled end time. So you may end up pulling from the grid at peak times at a higher rate than what you've just exported out at.

WW are aware of this and I think a short term (revert ECO as soon as target SOC reached) and long term fix (adjust the export rate and spread across the whole schedule) is on the cards.

ALLENPATTRICK

nbullus new to Octopus Flux and have followed the postings with interest. I have set up both the charge and discharge schedules as suggested.
I hit the problem described when the SOC is reached during discharge and Imports are enabled until end of specified period and have not found an automated and fullproof way of avoiding it entirely.
I eagerly await a way of reverting ECO once SOC has been reached.
In the meantime I am changing the duration of discharge as well as ensuring that the SOC limit will be reached by 1700. I use a Growatt 3600 invertor and have around 10KwH of useable battery storage. My base load is c.500 watts per hour and generation of 8-15 is a reasonable expectation.
At present at 0200-0500 I am charging the batteries to 100%. This is to ensure that I have sufficient energy in the batteries to cover the peak period 1600-1900.
I can reasonable expect my batteries to have a charge in the range of 80-95% by 1600 and will if necessary run an ad hoc program to ensure 80% is reached. Last night at 1900 SOC was 93% @ 1600 and 86% @ 1730 when the discharge/export commenced.
When my discharge/export program runs between 1730 and 1900 with a desired SOC of 20% it reduces the SOC to a useable 28% at 1900. At 1900 it reverts to daytime rates for Flux. The 28% is not enough to carry me through until the cheap tariff at 0200 but since the day rate for importing (28.79p) is almost the same as peak selling rate (29.31) this is no an issue.
Looking forward to a fix which will make life so much easier. I will certainly be using Wonderwatt then.
May thanks

admin

MarkyMark That's because you have smart charging enabled. As per my screenshot, disable Smart Charging (which uses solar forecast and SOC etc), and set a fixed percentage of 50% as target SOC.

The 'Charge at least' setting on Smart charging only is used when the Smart charging calculated target SOC is less than the Charge at least value. As your Smart charging target was > 50%, it wasn't set.

You want to use a Fixed schedule, not the Smart schedule.

MarkyMark

admin Thank you, I have now done that.

nbullus

ALLENPATTRICK Hopefully WW will fix the export issue and revert back to normal discharge once the target SOC is reached. There is a workaround you may be able to try in the meantime by splitting your single 1.5 hr export schedule into 3 smaller export schedules, e.g. 3 x 30 min windows. Your SOC target will then be checked 3 times (at the start of each export window) and prevent it running for the full 1.5 hrs if not needed.

I also found that exporting beyond 50% left me short before the 2am off-peak charge and I have 13.5kWh battery. Try increasing your export SOC until you find a suitable threshold that keeps enough in reserve to get you to the off-peak charge.

admin

ALLENPATTRICK Yeah it's next on the list to tackle. Just need to work out the best way without unnecessary server load and API calls.

ALLENPATTRICK

nbullus thanks for that. I will give your workaround a go next week. It is more elegant than mine. I also prefer the Wonderwatt interface to Shineapp.
Regards

ALLENPATTRICK

I have split my schedule into 3 x 1 hour and ran it successfully tonight. The parameters used for each were :-
50% for required SOC

Solar forecast
45% Target SOC
I was obliged to lower the forecast from 15 to 5 to get the schedule started.
Each of the 3 identical procedures worked perfectly. 50% was reached 50 minutes into the second macro and 45%. The 3rd macro initiated no further discharge and my battery was immediately deployed to satisfy consumed power. The macros run from 1600 to 1659, 1700 to 1759 and 1800 to 1900. The results are exactly what I wanted. Some fine tuning may be required to match the required SOC with load requirements between 1800 and 0200 as you suggested.

I am unclear why there should be any need to have the power parameter parameters or how it is used. I will be changing the parameters on each of the macros tomorrow evening to :-
30% required SOC. Solar Forecast 2. Target SOC 55 (after confirming with tomorrow’s results)

Do you see any problems?

Many thanks for your help.

nbullus

ALLENPATTRICK Glad to hear it has the desired effect. As previously mentioned, this is only a temporary workaround until WW get their own fix deployed to stop the export and revert the changes once the target SOC is reached.

It will take a few runs to fine tune the schedules to your exact setup and requirements, but there should be no need to adjust the power output. I may have misunderstood your query as I see no power parameter on the export schedule. WW are looking at two export options, maybe user selectable if they are both implemented:

Reached target SOC at full power and then stop before export end time
Reduce the power output to spread the export over the whole scheduled period and end at the scheduled export time.

Both options should have the desired effect of preventing the export finishing early and drawing from the grid for the remainder of the schedule, but the option that is best for you will be whether you want to finish export early and start using your battery, or holding off using the battery until the end of the export schedule. Remember that the export schedule will export both to the grid and to your home at same time so I prefer option 1 as it will always have the desired effect and never draw from the grid when you don't want it to. Option 2 relies upon getting the export power set right to ensure you export what you want whist still supplying home demand in the scheduled export period. If the export power is too high or your home demand drops then the target SOC could be reached too early and still draw from the grid for the remainder of the schedule. If the export power is too low or your home demand increases then you may not reach the target SOC for export that you set.

These are just my thoughts and I'm sure WW will be looking into this in greater detail than what I have to ensure both GE and Growatt batteries are controlled accordingly.

ALLENPATTRICK

nbullus my mistake. The parameter I should have referred to was that for the Solar forecast. There is no need for a similar parameter when scheduling an export/discharge direct on the Growatt interface. Should a low default value be provided? Perhaps I a missing the point but placing a high forecast value in the box prevents the schedule allowing discharge to take place which is counter intuitive in a high excess situation.
Thanks for your thoughts on the fix for exporting times and I really appreciate help.

nbullus

ALLENPATTRICK I'm with you now.

Assuming you are on Octopus Flux and you export at peak time (4pm-7pm), the next days forecast is irrelevant if you are re-charging the battery in the off-peak Flux period (2am-5am). You could therefore leave at zero value. You just need to leave enough SOC after export to get you through to the start of the off-peak charge schedule,

However, some people may be on different tariffs and export their battery at different times to that of Flux. Therefore they may want to only export the battery if they are not going to be left short by a low solar forecast. It's very easy to get caught out by exporting the bulk of you battery only to find out the solar generation is low and you start having to pull from the grid. In this instance they may prefer to preserve their battery rather than export and use it when solar generation is low to get them through the day. It's just another flexible setting that people may or may not use depending on when/how they export based on their specific battery size and tariff.

MarkyMark

Force discharging in the peak on flux and then using from the grid because your SOC has dropped too far is not too different when it comes to cost, you sold at 29.3p and bought back at 28.8p/kwh. So getting it wrong occasionally is not too much of a big deal (taking into account the 10% losses with using a battery). Compared to selling at 29.3 and buying off peak at 17.3, that is where you can make money, and more of course if it is generated. Roll on me getting my export MPAN, 2 weeks so far waiting.

nbullus

MarkyMark This is fine if you export in peak and pull from grid in the daytime period. However, Octopus will never set the import rate so close as the export rate for the same period. My Flux rates are 39.37p import and 28.37p export.

It's for this specific issue that WW want to avoid someone setting up say a 3hr discharge (4pm-7pm) at say 28.37p, and after 30 mins you reach your target SOC. The remaining 2.5 hrs of the export schedule will then pull from the grid (as ECO won't get reset till after the 3hr schedule ends) at 39.37p resulting in an overall loss for the export period.