PredBat - moving from IOF to Agile

I've installed PredBat whilst still on Intelligent Octopus Flux - planning to move to Agile import in November and Fixed 15% export. It's obviously in monitor mode for now!

Is there any gotchas I need to be aware of when I change tariff and I'm ready to go?

The plan, I think is:

• Comment out the manual import tariff prices
• Uncomment the metric_octopus_import line (I've already enabled the next_day etc rates)
• Not sure if I should keep the export price manual, or use the metric? (will it work on the fixed 15p)?
• Update the prices in the energy dashboard (update it to use the price from the Octopus Integration - it's currently hardcoded!)

Does it take a while for the API to update with the new tariff details and prices?

I've got all the charts, dashboards and the predbat plan html sorted. Plus solar forecast and carbon intensity sorted too.

Not sure about database sizes - is that something that is a problem with PredBat or just the PredBat AI version?

Any other things to watch out for?

TX200 there's no specific things to do, it sounds like you have most things sorted.

Before you swap I suggest you turn on control charge and discharge, then set read only to true. Predbat will then plan but not execute your battery activity and you can tweak the settings so you are happy.

Can either set the export rate sensor or the manual rate in apps.yaml, it makes no difference.

When I changed From Flux to Agile the sensors changed straight away to the new rates, I didn't have to do anything in predbat.
But probably worth deleting the security access token for octopus from your givenergy account to stop any rogue octopus control.

There's no specific issue with the database size and predbat, just as long as you keep your days history to retain sensible. 14 days is ok, if you set it very high then your database will grow substantially.

Welcome to the world of predbat!

Cheers, yeah was planning on pressing the disconnect inverter button on the Octo app, then kill the token too.

Just tweaked the minimum SoC from 0.5 to 0.25 as it’s a fairly small battery so want to make good use out of it (5.2/4.8), plus I earlier updated the battery DoD scale to 0.8. Plus updated the AC limit to 3600, didn’t spot that one earlier!

It takes Octopus a while sometimes to change the export rate although it should take effect at the same time as the import change. You might want to put some manual export rates in to stop Predbat exporting in the peak IOF slot (or any other slots) until Octopus change it.
I changed from normal Flux to Agile/Fixed outgoing and I had to give them a nudge to complete the export set up.

TX200 Just tweaked the minimum SoC from 0.5 to 0.25 as it’s a fairly small battery so want to make good use out of it (5.2/4.8), plus I earlier updated the battery DoD scale to 0.8

Yes, if you’ve got one of 5.2 batteries you need to set the battery scaling to 0.8 as you’ve done.

Just to clarify, you probably want to set best_soc_keep not best_soc_min to 0.5. best_soc_min is the amount of SoC that Predbat will keep in the battery all the time (e.g. for power cuts), so unless you really want to reserve some power and have an EPS wired up to your battery, set this to zero - if not and your house demand exceeds the prediction then Predbat will charge the battery (regardless of rate) to maintain the best_soc_min.
best_soc_keep is the advised level of battery you want to keep, but can be exceeded. You might need to experiment with this, you want to ideally set it to just above the 4% battery reserve SoC. If you set it too low then weird things can happen…

As SJB points out, it has been known (happened to me, and to others) that Octopus swap you onto your new import rate but forget about the linked export rate. I was on Agile import and Flux outgoing for about 6 months before Octopus realised and of course then back dated the change to the 15p fixed export.
So probably best to manually configure your export rate until Octopus definitely gets the export swapped

geoffreycoan I don't appear to have an entity called best_soc_min ?

Looked through all the "bests" and couldn't see anything with a similar name.

TX200 its 'input_number.predbat_best_soc_keep’

https://springfall2008.github.io/batpred/customisation/#battery-margins-and-metrics-options

geoffreycoan yeah, I can see that one, just not the other one you mentioned.

TX200 ah best_soc_min is an expert mode setting which is why you can't see it.
Most things you can do without expert mode being turned on, it's fine

Almost there. Import sorted, home assistant seeing the new tariff and prices.

Predbat is now looking at the dynamic metrics for import and export tariffs. And it is now out of read only, controlling charge and discharge.

Move to outgoing agile completed just now, I can see that on my octopus homepage, just waiting for the API to update.

Decided to try outgoing agile as I suspect most of my export will be 4-7pm, not much sun this time of year and if there is any it can hopefully go to the battery first. Fingers crossed.

Did a reboot of HA and HA now knows my new tariff. 😀

Did similar for the import, it udpated after a HA reboot.

So I wonder if it would have come through at 11am and rebooting just caused the BottleCapDave to do a fresh query rather than wait for an event.

TX200 So I wonder if it would have come through at 11am and rebooting just caused the BottleCapDave to do a fresh query rather than wait for an event.

In both of my experiences of changing tariffs, the Bottlecap dave Octopus integration picked up the change and applied it automatically to the prices that Predbat used. There’s loads of different Octopus API’s and the integration polls them at different frequencies so as to not cause a ‘denial of service’ attack on Octopus with continual polling. The frequencies is in the documentation somewhere, probably rebooting HA caused a re-poll a bit quicker as you say.

Be interested to see your experience of Outgoing Agile. As you say limited solar export this time of year anyway. You will miss out on ‘brown export’ when the agile import prices are super-low and its worth repeatedly charging and then discharging on Outgoing Fixed, but whether this is made up for the better export rates in the peak period 🤷‍♂️
Also need to consider what happens with DFS this winter and how much we reduce our peak period exports to ‘save our average export kWh’ for the DFS sessions.

Good point re the cheap or negative periods and cycling the battery, I hadn't thought of that. Seems a bit cheeky, but if they offer that combo of tariffs...

I'm not sure how much I'll export Vs use (e.g. cooking) during the 4-7pm peak. Will see how that goes. Hopefully still some headroom for DFS benefits, although I understand there's no test events this year. Of course Octopus could decide to do it's own thing.

So despite the current prices, managed 18.4 p/kWh over the first seven days of the new tariff

Flux off peak was 20.43 p/kWh

A saving of 82p so far. 🤣

Not going to compare actual prices due to the weather. And not comparing to last year due to some dodgy data in home assistant at the start of Nov 2023. Dodgy data came from GivEnergy portal. Plus there's the whole import to export thing on IOF.

So, did I choose the wrong export tariff, should I have been on 15p rather than agile outgoing...

Well, today I missed out on about 80p

My peak rate exports (which I consider to be 4-7pm) have averaged out to 25p/kWh, so better than the 15p

The off peak rate exports are a lot lower than 15p, but until today agile outgoing was still winning.

I might move export tariff next month.

TX200 Its really dependent on how much you can export in as short a time as possible on Agile Outgoing. ie 1600-1900 potentially.

I found it was an exercise in futility on a G1 inverter & 9.5kWh battery, so the fixed rate 15p tariff was much more useful.

Vestas I think it also depends on how well your battery covers your daily house load. I have 13.5kWh of battery capacity which will cover a whole day’s load, but now the ASHP is on, that consumes at least 10, more usually 20kWh a day, so there’s practically no space capacity for forced exports.

There’s two opportunities for forced exports for me; when there’s plenty of solar and the batteries are full, which in the winter isn’t that often; and when there’s low agile rates and Predbat can repeatedly charge and discharge the battery for a profit, so windy and not cold days are a great money-earner for me. -£3 or so today which I wouldn’t have got on Agile outgoing.

So, November average import price was 13.4p

Better than IOF (21.8p off peak, if I recall correctly)

Asking octopus to move me to the 15p fixed export (well, variable 15p export now guess).

My average was coming out circa 14p on agile outgoing.

TX200 Makes sense. Everyone’s situation will be different but for me I’m not generating much at the moment, a ‘good’ day is 5kWh, and all that is getting consumed by the ASHP.

Really the only time I am likely to be exporting is when Agile import rates are low and the Agile export rates would be low also so there’d be little financial benefit to doing so.

I’m sticking with the 15p export, mine is fixed to April next year