Hi all.
I last month signed up to Beta test a VPP (Virtual Power Plant) with Axle Energy.
Just thought I'd share my experience so far...

I have 4.2kwp of panels with a Givenergy 8.1kw Gen1 battery & 5kw Gen 1 inverter.
Because of the vintage of the inverter, there are not many charge/discharge slots natively available. Here WonderWatt has been REALLY useful for optimising usage/storage/export.
I was up until last year participating in Octopus saving sessions, but have switched to a different supplier now.
I saw Axle VPP was looking for Beta testers so signed up. You can join giving Axle either full control of your system or participate in DFS events only.

Axle currently offer £1 per kwh exported during any events in addition to any normal payments you receive for exporting to the grid. Axle also guarantee at least £10 per month of rewards while you participate in the scheme.
So far it has been mostly as expected. Battery charges overnight on cheaper rate electricity, used normally through the day with the panels and inverter set to Eco mode. During events Axle export as appropriate.
There have been a few glitches where the battery has failed to charge overnight, but that I guess is to be expected on a Beta product, but overall it has been a positive experience.
I have earned just under £40 of rewards for the month of November from Axle plus my export rate from my supplier.

Just thought I'd put it out there for all.
BTW, it will work in conjunction with WonderWatt or any other scheduling app if you set the dispatch optimisations as you require.

Here's a link to check them out and earn a joining reward: https://vpp.axle.energy/landing?ref=R-EGRHGUET

Sorry for the long post and thanks for reading!

Interesting. I've just read the info on their website, it can either offer fully managed mode which would appear to deliver wonderwatt or predbat-like battery optimisation, or event only mode where you only get the savings events scheduled for your inverter.

It explains in the FAQ how this is different from DFS sessions, but doesn't say that you can't join Axle as well as any other DFS session provider - I wonder if this is allowed?
https://vpp.axle.energy/landing/grid

The £1 a kWh and £10 minimum a month is tempting, a bit like DFS when it first started we were getting rates like that, I can't imagine it continuing given what NESO pay. Even in extreme stress DFS events is rarely more than 30p/kWh now.

Am tempted to apply if I'm eligible

I'm on "Events Only" (was on the full fat optimised mode but it had a habit of failing commands leaving me with no charge over night - they've yet to learn that it's best to send the same commands a few times to Givenergy kit to make sure it sticks!) - £10 month for not really doing anything seemed a no brainer. It didn't really seem to care if i was in saving sessions or DFS on signup.

Thanks Hoggy and Chris, I’ve signed up and will next need to start some Predbat automations to relinquish Predbat control when these events occur.

The signup process is pretty slick and easy to follow, you upload your recent supplier bill (Octopus in my case) and Axle extracts your supplier/meter details and current tariff. It got the import tariff correct but for the export I had to tell it what I was on, possibly because I had swapped export tariff in the last month so both Outgoing fixed and Outgoing Agile were on my bill.

Once past that, created a GE Cloud API key. The website wasn’t as easy to use here, it defaults to a dummy API key and it took me several goes to be able to edit the field and remove the dummy value before pasting my new Axle VPP API key in.
Several times my API key was rejected. I tried reducing the amount of access Axle had, in particular I didn’t want to give it “lock” permission because I’ve seen others with problems with the locks remaining when they shouldn’t, but every variation I tried my API key was rejected so in the end had to give it full access.

And all done, account created, HA REST sensor created, waiting for the first event.

geoffreycoan
Hopefully you managed to sign up before the recent DFS event.
I only managed a small export during the time (Mrs P was baking Christmas cakes) but still earnt a few pounds.

chrisppokit Hi Chris, I’ve not seen any events since I signed up. Hoggy said there was one on the day I signed up, but I was only an hour or two before it happened so I might have been too late for it.

At the moment I have just created an automation to alert me when there is an event, and I can then work out what to do with it, when to turn Predbat off from controlling my battery, etc.

Thanks

Thanks for the tip off - I’ve gone for the “event only” dispatch mode also.

Just signed up and added as events only .
Also added HACS bit to HA to see events

wrighar I found that HACS integration as well. I couldn’t really see the point of it. Adding a REST sensor is a few lines of YAML, already provided by Axle. The integration does exactly the same thing and just adds to your integrations list with a bit of 3rd party code.

A FR has been raised to add Axle support to Predbat https://github.com/springfall2008/batpred/issues/3051

Personally I think this is a bit niche to a small user community. I’ve written a couple of automations to notify when an event occurs and to instruct predbat to force export for the duration of an Axle event - details in the above github issue

I've added your automation predbat trigger to my automations.yaml, and also the axle-vpp bit to configuration.yaml (although I've not deleted the davidhall hacds addon yet....)

We'll see how it goes

wrighar And assume I don't need this:

# - action: script.notify_all_devices
'# metadata: {}
'# data:
'# title: “Axle Export Session "
'# critical: "N"
'# url: " /dashboard-givenergy/plan"
'# message: From {{ start_dt }} to {{ end_dt}}

wrighar no you don’t. I have a script that sends alert to my mobile devices, and then I use that script in all my alert automations. You could just make a call to notify.xxxx your mobile device.

The script doesn’t do much over a straight call, the ‘critical Y/N’ varies whether the alert is transient or permanent and whether a sound is played or not, that’s it really

I have a question about this... does the system completely empty your battery when exporting, or does it reduce the SoC just enough that the battery would last you through to the next charging period?

CW does the system completely empty your battery when exporting, or does it reduce the SoC just enough that the battery would last you through to the next charging period?

I had thought about this as well, because the experience of people on the GivBack scheme run by Axle in prior years was that it would import beforehand and export at the DFS rate, regardless of what the consequences of this was. I was on Agile for most of last winter so it would have been quite expensive and almost definitely not profitable.

The latter would be possible though if Axle built up a picture of your discharging losses, solar generation and historic house load, so is do-able, but adds quite a lot of complexity.

My assumption is that it is a full rate discharge at whatever your inverter can deliver.

But, given that they are paying at least £1 a kWh for your export in the VPP scheme plus whatever you get in normal export rate, you will be still making a profit even if you have to import afterwards.

Not had any alerts yet so the above is all a hypothesis.

Interesting video from Fox ESS & Axle Energy explaining how it works:
https://www.youtube.com/live/6I_TShubenc?si=KSW8VauFa7BsVk2Y

I spent all week checking the REST sensor wondering if I had configured it correctly or not.
Then found out that there is an Axle VPP Beta whatsapp group

A message was posted today:

Hi all,

A quick update on this week.

We know there's been a lot of excitement and questions about upcoming events! This week, the grid stayed nice and stable thanks to the warm and windy weather, so no events were needed.

Grid forecasts suggest an event next week is probable. As always, we'll let you know the day before if one is scheduled.

Thanks again for your support and engagement - we really appreciate the enthusiasm!

Cheers,

George

So 🤞 for next week something happens. Its good to see the confirmation that we get a day before’s notice

geoffreycoan my bet would be Tuesday 5pm. There's a 33GW deficit between demand and what wind is producing.

hoggy the Agile predict and Octopus Greenness index both have a spike occurring on Tuesday evening

But suggest it is the 18:00 slot

But the portents do look good for Tuesday. Be interesting to see what I get on Agile Outgoing as well as Axle

A new field appeared tonight:

wrighar I don’t see anything different on mine, the None state has been set all week and goes back to Thursday last week, which is when I signed up for Axle I think, and created the REST sensor

It seems that Givenergy are probably countering (although probably not exclusively to Giv gear) :

And the reason I say probably is because Givs owner also has something called PWRDG UK LTD (not too hard to work that back)
And potentially also setting up some sort of bricks & morter retail?:
https://find-and-update.company-information.service.gov.uk/officers/vzwl9K3YNHr2emyVXYn6JRRM2ho/appointments

hoggy I saw mention of that email on the Axle VPP Whatsapp group. I didn’t get the email 😥

I think it was said before that Axle no longer provides the Givback service for GivEnergy. Clearly there is money to be made in this VPP business, would have thought Octopus would be doing more over and above what they do with OIF?

That mention of an email would be me!
Octopus seem to have stalled a little lately with this kind of thing - IOF still only supports a small selection of inverters and EV chargers. I guess the smaller VPP companies can get things out the door pretty quick.

OK I've had serious words with the wife so that she doesn't turn on every appliance at the time of the event and signed up using chrisppokit code (already £25 up).

Here if anyone wants it, is my Axle referral code https://vpp.axle.energy/landing/grid?ref=R-VNNIZUYO

geoffreycoan
Done!

….and here is my link for anyone else.
https://vpp.axle.energy/landing/grid?ref=R-QCZJVTJM

Thanks Watcher, it came through

First grid event for me tomorrow morning:

My REST sensor hasn’t picked this up yet, but it only polls every 30 minutes or so

What's the correct strategy here with no automations set up? Register the revised £1.15 export rate with Predbat and put Predbat in read-only mode? Can it be scheduled?

For now, I've just added the 1hr export rate to my apps.yaml, so Predbat has scheduled an export itself.

That's what I've done for myself (having signed up on this). I've setup an automation to toggle read only at 7:59 and then again at 9:01 - hopefully that'll work. If not - I'll check it manually.

Being a bit slow maybe, sorry, does being part of this scheme mean I would have to de-register for any Octopus Enerygy saving sessions, Free electricity etc?

Mouton

No, this is when the grid is struggling so opposite times.

browellm What's the correct strategy here with no automations set up? Register the revised £1.15 export rate with Predbat and put Predbat in read-only mode? Can it be scheduled?

For now, I've just added the 1hr export rate to my apps.yaml, so Predbat has scheduled an export itself.

There are some automations shared (and iterated as we test them) on github: https://github.com/springfall2008/batpred/issues/3051

But setting a rate_export_override in apps.yaml with a rate_increment of 100 will do the job perfectly, predbat will pick up the extra rate and should schedule the export itself.
Alternatively you can do a manual_force_export for the time slots, the automation does that as well as set the export override

MikeyHaz That's what I've done for myself (having signed up on this). I've setup an automation to toggle read only at 7:59 and then again at 9:01 - hopefully that'll work. If not - I'll check it manually.

That was sort of how I was thinking of handling it. Axle say they send the event instructions through to the inverter “just before” the event, but what does that mean? I was thinking 10 or 15 minutes before would be safer to set predbat to read only mode to allow the Axle commands to come through, or just set a manual export in the time slots will ensure that predbat plans to export when you need it

geoffreycoan

Good call - I've adjusted to give a 15 minute window.

I've setup the HACS integration - setup an automation to react to that start date field, set two date/time helpers and then setup the toggle read only automation to react to those helpers +- 15 minutes.

I've also borrowed your idea from the github thread of forcing in the export override so that it plans in the battery charge and the discharge, but then my plan is to let Axle take over so that they know they did it.

So in theory - it's automated.

No idea what it's all going to do after the event - guess we'll see what the HACS integration returns!

Leeshore Thanks! Hopefully you're set up in time for Tuesday mornings event.

geoffreycoan It looks like there is an event tomorrow - I would be interested to hear how they handled your system regards SoC etc

CW I’m on event only so I am managing the SoC myself. I’m on Cosy so there’s a 3 hour charging window immediately beforehand from 4-7am, then the Axle VPP event 8-9 so I should be full beforehand.

There’s not a lot of solar tomorrow but it doesn’t look like it will be cold tonight or tomorrow morning so even after the Axle discharge I should have plenty of SoC to last through to the 1-4pm Cosy slot.
Worst case I grid import at 28p, am still making money from the £1 Axle payment

Maybe I misunderstood - but nothing happened at 8am to my system. I ended up turning predbat back on and letting it discharge.

I thought the 'event only' mode meant they would take control in an 'event' but otherwise leave me alone?

Mine started dumping a few minutes after 9, and is still running at 8:45.

Watcher I signed up, but wasn't invited to take part in this event. (Signed up too late ?)
May I ask exactly which registers they set/changed, and when? I'll need to adjust my scripts to prevent interference.

DD
Sorry, do not have that depth of knowledge perhaps @geoffreycoan can advise?

Follow up email from Axle…
Hey,

The grid event has now ended - thanks for helping out!

We'll drop you an email letting you know how much you've earned as soon as we have the data (typically within 48 hours).

If you're on Event Only mode, we will have tried to automatically revert your battery settings back to normal. Please check your settings as we're not always able to reset these remotely.

Thanks for helping out the grid,
Axle Energy

…had to switch eco mode on manually.

There’s quite a bit of chat about others experiences of the event on the GitHub issue https://github.com/springfall2008/batpred/issues/3051 and the Axle Whatsapp groups.

My feedback is that the event went well, some observations:

• Predbat started the export at 08:00
• For some reason I don’t quite understand Predbat changed the inverters back to Eco mode at 08:02 and then back to export at 08:03
• Axle cleared the REST sensor details of the event at 08:05. Fortunately my automation ignored this but others said this caused them to stop exporting. This has been reported
• Throughout the event Axle and Predbat argued over the end time of the event, Predbat wanted 09:01 because it always exports for 1 minute longer to ensure it runs through the end time correctly (it will come along at 09:00 and clear this), but Axle wanted precisely 09:00 so my end time swapped back and forth

But otherwise no major dramas. I exported 4.6kWh.

BTW my automation to sent Axle events to Predbat is at https://github.com/springfall2008/batpred/issues/3051#issuecomment-3657926392

Beware that as Axle have argued for on device metering rather than smart meter - if you set both your inverters to discharge you'll probably only get paid for one (the one you signed up with)

Watcher same here. It didn’t revert to Eco mode. Gen 1 hybrid.

Thanks for the heads up.

hoggy I didn’t sign up with a specific inverter, I signed up giving Axle API access to my account which has both inverters on it.

Looking at the discharge end time being swapped back and forth it appears that Axle was controlling both inverters which TBH is what I would expect it to do:

And I’ve heard that it wasn’t just the discharge end time that Axle fought Predbat over, another person has reported that their reserve SoC kept being swapped between 4 and 10%, presumably Axle wanting a to-empty discharge and the OP having a reserve limit set higher.

On the github mentioned someone has been in contact with Axle to question whether they would get credit for the full export in the period even if it wasn’t initiated by Axle (it was late and for him the export flipped on and off), and they confirmed that you’ll get credit for the full period you exported even if you initiated the export yourself, it didn’t matter.

Am a bit surprised by the 8-9am timing of this session, the day-ahead spot prices you linked before @hoggy showed it high but not that high, and Outgoing Agile was only paying me 9p/kWh for the slot. The grid seems more strained this evening in the peak when its getting colder, my Outgoing rate is 20p then 🤷

Maybe they've changed their mind - when I asked about mine was told multiple inverters weren't something they supported - guess well find out in a few days if the money is about right.

Timing wise it matched the early morning peak but yes it does seem odd they didn't aim for tonight. They'll see things we don't though, so perhaps they chose that peak instead of the big one knowing they were up against some bigger players and might not necessarily win bids.

geoffreycoan Predbat wanted 09:01 because it always exports for 1 minute longer to ensure it runs through the end time correctly

Is this 1 minute overrun hard coded into Predbat?

browellm Is this 1 minute overrun hard coded into Predbat?

I have a feeling it is configurable somewhere, but I searched the documentation and my predbat controls and couldn't see how to turn it off.
You can set inverter charge/discharge start/end skew in apps.yaml https://springfall2008.github.io/batpred/apps-yaml/#clock-skew and I'd imagine that that is one way how to turn it off, but you'd think it would have had to be configured like this in the first place rather than using this to turn back something predbat does.

I probably need to look at the code to figure out what its doing.

I seem to have dumped an hours worth of battery again 8-9 this morning.
Discharge instruction from yesterday not cancelled by Axle.
Anyone else?

Yeah I caught mine beforehand, but what I forgot to check was if they re-enabled overnight charge - which they hadn't - so it was completely flat anyway (which I guess in a roundabout way means task failed successfully...)

Watcher Looks the same on mine, the last set of commands sent by Axle at 09:18 included turning Eco mode off and turning the discharge schedule on, which would have resulted in the inverter running off grid and discharging again today had Predbat not intervened and reset these correctly

I had no issue:

Leeshore I had no issue:

It looks like you didn't receive any Axle commands today. We've identified that the last set of commands sent yesterday by Axle left the inverter with Eco off and the discharge schedule still enabled so if you (or something else) didn't change it, the inverter would discharge again today at the same time

geoffreycoan

It looks like predbat did it for me and then axle did.

hoggy I also had a flat battery this morning. Weird how flakey this is considering the GivBack service worked fine.

Results are in:

Got my credit as well, the graph is of meter readings (spot the Cosy cheap periods when I import and my batteries running out in the late evening, so a bit of import then)

Happy with that

Watcher same here - I’m away and only just catching up. Didn’t get a single email from them and haven’t seen an invite to a WhatsApp group.

5 days of not being back in eco mode, not charging overnight, and exporting 8-9a each day.

Very annoying.

26Left Didn’t get a single email from them and haven’t seen an invite to a WhatsApp group.

the link to join the Axle whatsapp group is on the bottom of the signup email from Axle “your battery’s just got smarter”. I missed it initially as well

BTW new version of Predbat 8.30.0 (currently on main for testing) includes direct predbat support for Axle events, you just configure your Axle API key in apps.yaml and Predbat will poll Axle every 10 minutes and update your plan when an event occurs. Option to set predbat to read only during an event so Axle can control the inverter directly, or (as I did), just let Predbat do the force export which in my case meant I started exporting at 08:00 whereas the Axle instruction didn’t arrive until 08:11.

There’s definitely some rough edges to the Axle VPP, I guess that’s why it’s still in Beta test.

geoffreycoan don’t have a single email from them - nothing in spam. Would you mind copy-pasting the link here?

26Left No problem. Here’s a copy of the signup email

The WhatsApp link is https://chat.whatsapp.com/I54u2IWcB921dc8TaWImIK?mode=wwt

There are separate community groups for General chat, Home Assistant and the different inverter types

geoffreycoan I got that email, but no chat link at the bottom. Perhaps the beta was intended to be limited?

DD no idea. Anyway you should be able to join the whatsapp community now

This is interesting and great it seems for Agile. Presumably this arrangement would be no good for when I switch back to IOF in spring?

geoffreycoan Unfortunately not - "this invite link was reset"

Can I just check my understanding?
I have signed up to Axle and have added the following to my apps.yaml

Axle Energy VPP configuration

axle_api_key: eyetc
axle_pence_per_kwh: 100 # Default payment rate
axle_automatic: true # Auto-configure sensor
Does everything now happen automatically, polling and adjusting the plan or are there any more steps that I need to do?
Confused from Essex!

geoffreycoan Could you please help with exactly what I need to add to apps.yaml for Axle to work with Predbat. I’ve signed up with Trefors referral code after updating to v8.30.1 and generated my Axle API but I can’t find in the documentation on exactly what and where to add.

Goshiki2
I have added the apps.yaml entries as per my post above and I am now seeing Axle events in my entities list.

I've now updated to Predbat 8.30.0 and then 8.30.1

Added the 3 Apps.Yaml; entries

and commented out my old configuration.yaml code of GC's

all you need to do is to add the axle_api_key to apps.yaml. All the other config options are optional. Predbat will create binary_sensor.predbat_axle_event with details of current and historic events it has handled (so blank right now)

Not sure how long they'll be able to do that....

I got mine topped up today as well although I'd earnt £4.68 so less of a topup for me.

In the signup it does apparently say this is trial until March 2027 and then they'll evaluate the rates and guaranteed minimum payout. So we've got a few more months of this. Hope there will be a few more sessions as well

wrighar That's interesting... I was just thinking that there hadn't been much activity to justify their promise of £10/month

Next week will be cold, not particularly windy, businesses back at work, all leading to the Agile price prediction giving some very big price spikes in the evening peak. Looks like we could be having some Axle events?

Heads up:

Hey,

Heads up: we’ll be exporting from your battery tomorrow 2026-01-06 from 08:00 to 09:00 to help relieve grid strain in your area.

We’ll pay you £1/kWh for energy exported to the grid. You don’t need to do anything - we’ll handle this automatically and reset your settings afterwards.

geoffreycoan Good prediction

Looking good

I'm only getting £1.13 and £1.14 per KWh because I'm on Agile Outgoing and the rates are not that good in the morning !

Those using Predbat may have noticed that predbat doesn't alert when there is a new Axle session. I've fixed this and the code change is awaiting Trefor's review

Just a thought before this morning’s session starts. Taken from an earlier post. “just let Predbat do the force export which in my case meant I started exporting at 08:00 whereas the Axle instruction didn’t arrive until 08:11.”
Does this mean that we would only be paid the Axle rate from the time of receiving their instruction?

Goshiki2 I think they get data from smart meter which has half-hour resolution. And I think they said somewhere that you get paid regardless of who triggers the export.

Predbat has started exporting but now thinks I'm earning £2 a kwh

MikeyHaz Same as mine. It was sitting at £1.16 until the Axle event triggered at 08:09 and then it added another £1 to it so I assume Trefor is double counting

Goshiki2 looks like they didn't bother sending instructions to my inverter until 8:21 ? And seem to have made some unnecessary changes - will be interesting to see how well they restore things afterwards. (I'll have to write to suggest they fill in in identification field when using the API.)

DD Agreed. Looking at the activity log in the Giv portal there is an ongoing battle between an API changing the discharge target to 10% and then a few seconds later, Predbat changes it back to 4%.
The same with discharge end time, API wants it to be 09:01 and Predbat wants it to be 09:00

Well... the log shows the API setting things up correctly at 08.01, and exporting correctly until 09.03, at which point it reset the DC discharge back to Off, re-enabled AC Charge, and turned Eco back on. BUT then at 09.04 it disabled AC Charge again - which if I hadn't been looking out for it would have disabled my cheap rate charging tomorrow morning...

My AC Charge off as above, too.

As mentioned above, Axle have previously confirmed that they will pay for all the energy exported, regardless of how that was invoked, In my case the Axle instruction didn’t come through until 8:07 but Predbat had already started the export at 8:00. The smart meter is only to half hour granularity anyway so no way could they work out which was due to their instruction.

There is a tussle between Axle and Predbat over some of the settings, but I wouldn’t worry about that, and also as above there’s a bug with Predbat doubling the export rate during the event. I’ll take a look at it today.

Not quite sure what the £'s on the right are right...
about 4kWh exported.

8:14 for Axle instructions arriving for me. That's better than last time where they didn't arrive at all.

Saw the same tussle as all others with Predbat (9:00 v.s. 9:01).

AC Charge was turned on at the end, eco was initially turned off for a few secs - then put back on.

Perhaps Axle need a 'just let the end user do it' mode.

I'm not complaining too much - that's two sessions where I've been able to force export a couple of KWH. It's not earning me millions - but it's better than a kick in the teeth and the system is largely automated for me with minimal input (just making sure I shut down as much of the house load as possible to maximise export).

For those using predbat, I have worked out why the export rate gets duplicated in the event, basically the current and historic events are counted as axle sessions https://github.com/springfall2008/batpred/issues/3051#issuecomment-3714130591

MikeyHaz Perhaps Axle need a 'just let the end user do it' mode.

I suspect Axle can offer higher rates because they can be more confident of export actually happening, whereas Octopus require opt-in and cooperation.

geoffreycoan there is a fix to the duplicated Axle export rates in my fork. If you want to apply it to predbat, details of the change is in the github issue https://github.com/springfall2008/batpred/issues/3051#issuecomment-3716631250

This issue causes the export rate to double during the Axle event, so messes up the predbat_cost_today, but otherwise doesn't cause any harm so you can quite safely wait for Trefor to include my fix in the next predbat release

I too had the constant battle with Axle changing what I think was more than they should and Predbat fighting back. 300+ records and changes made.

2026-01-06 08:14:30 You DC Discharge 4 Start Time Written Successfully 00:00 00:00 00:00 API - Inverter Presets
2026-01-06 08:14:29 You DC Discharge 3 Lower SOC % Limit Written Successfully 10 10 10 API - Inverter Presets
2026-01-06 08:14:27 You DC Discharge 3 End Time Written Successfully 00:00 00:00 00:00 API - Inverter Presets
2026-01-06 08:14:26 You DC Discharge 3 Start Time Written Successfully 00:00 00:00 00:00 API - Inverter Presets
2026-01-06 08:14:24 You DC Discharge 2 Lower SOC % Limit Written Successfully 10 10 10 API - Inverter Presets
2026-01-06 08:14:23 You DC Discharge 1 Lower SOC % Limit Written Successfully 10 10 10 API - Inverter Presets
2026-01-06 08:14:21 You Enable DC Discharge Written Successfully true true true API - Inverter Presets
2026-01-06 08:14:20 You DC Discharge 1 End Time Written Successfully 09:01 09:00 09:00 API - Inverter Presets
2026-01-06 08:14:18 You DC Discharge 1 Start Time Written Successfully 08:00 08:00 08:00 API - Inverter Presets

looks like there is another session tomorrow morning 10-11

Axle seem to be getting better at getting the settings applied ... 9:50 they turned off charge/eco and then 10:02 is when the 11:00/11:01 tussle started today.

even though i'm set to dispatch only, they are trying to charge my battery after the session, entirely unhelpful

keeps getting re-written every time i turn off the AC Charge Enable.

Mine seemed better today, the discharge time was programmed by Axle at 09:50, Predbat started the actual discharge at 10:00:24, but Axle sent its first discharge command at 10:01:54, much closer to the event start time than before

There was the same tussle with predbat over the discharge end time during the event

Predbat stopped the discharge at 11:00:22, Axle sent the stop at 11:01:23

Axle turned AC charge enable off after the event and set the discharge times back to what they were previously, i.e. from yesterday's event

...

geoffreycoan Hmm - they didn't come anywhere close to restoring my previous settings. They cleared all discharge slots during setup, with limits of 10%, at 9:50. Cleared the eco flag at the same time, which is a little rude, since that would take immediate effect (and is not necessary for a forced export anyway, on my inverter).

Unfortunately, the changes I'd made to my control scripts don't seem to have fully worked, since it still seemed to be resisting. Unfortunately, I had to go out, so couldn't keep a close eye on things. But I did manage some export, and at least the HP wasn't consuming most of the power this time.

DD its still very much a beta!

I exported 5.6kWh today (nice bit of morning solar, its clouded over now), and with the 4.7kWh I exported on Tuesday I'm over the £10 minimum payment which is nice. I'd turned my heat pump down during the session as well so was able to export from both inverters at max rate.

Some people on the axle whatsapp group have reported slow discharge rates due to their batteries being too cold.

Thanks for all your help with predbat and the Axle integration @geoffreycoan it went seamlessly today.

3.5kWh the other day and 4.4kWh today, looks like I might earn my £10 this month, rather than being given £9.30 like last month

I switched off export_freeze_only on predbat as I was unsure if that would impact it.

Probably a good idea to turn export freeze only off. I have it off all the time.

Got my Axle email for 6th January, it matches my Octopus app, says I exported 4.68kWh, earning £4.68. And Octopus will pay me 66p for the export as well.

Goes a little way to offsetting my £16.74 import bill for that day (83kWh).

geoffreycoan Goes a little way to offsetting my £16.74 import bill for that day (83kWh).

I'm so pleased to see someone else with import values similar to mine, I watch a number of YouTube videos and most of them talk about such small values that I feel like I must be doing something wrong.

GSH here, but
19.4 in, (10.2 @ 8.5p, 9.2 @ 30.6p = 87p+281p = £3.68)
4.7 out and (4.4 @ 115p, 0.3 @ 15p = 506p+4p = £5.10)
100.1 gas central heating.... (100.1 @ 0.0556p = £5.56)

Tally for day: £4.14 + 81p standing charges. = £4.95

More than expected, by the wife had the oven on for 3 hrs doing baked pots and cauli cheese, and 3 loads through the washing machine :-(

Anyone still waiting for results from 8th of Jan?

arczi19 No email, but it appears on the Axle account

ChrisLav Likewise, no email (I had one for 8th Jan) but the credit has appeared in my account

Seems to be unsure of whether I have earnt £5.37 or £5.36 though 🤷

Can see where my batteries ran out and grid importing starts, and then when grid import ramps up as I’m recharging the batteries in each Cosy period

I did 70Wh better than I thought, and extra 7p + 1p (from the 15p/kWh export)richer.
No email yet either.

I'll be skipping this one as my battery is offline.... :-(

wrighar annoyingly so is one of mine. I did a battery firmware upgrade on my 5.2 this lunchtime and since then the battery is no longer doing anything, its sitting there on idle all the time. Its also reporting low voltage in the portal even though the SoC is shown as 96%,

Very strange.

So have had to cope with one battery and inverter for tonight. Hope to get it looked at tomorrow

Did you check that the firmware upgrade worked? Maybe you have to do an SOC charge and discharge to get the system to read all batteries correctly? When I had a third battery added three weeks ago..this had to be done to get it all functioning correctly

geoffreycoan In the signup it does apparently say this is trial until March 2027 and then they'll evaluate the rates and guaranteed minimum payout.

Translated that means "we think we can grab enough customers/participants to claim balancing payments by paying stupid amounts of cash for a while". After that the customers/participants will be entirely secondary....

AndyZ900rs Did you check that the firmware upgrade worked? Maybe you have to do an SOC charge and discharge to get the system to read all batteries correctly?

thanks for the suggestions. I downgraded from BMS 3022 to 3017, then went to 3019 then back to 3022. At each stage the battery did the right beeps and flashing lights to indicate it had upgraded correctly, and the BBC basic app reports the new battery firmware version, but in every occasion the battery just sits there on idle and won't respond to either charge or discharge instructions from the inverter.

with a volt meter I have measured the battery cell voltage and the battery is holding 53V, which corresponds to the 96% SOC the battery was on before I started the upgrade. However the battery output to the inverter is only reading 8V and the inverter is giving a low voltage error.

So for some reason the battery management system has gone into a sulk, am trying to get some help from givenergy to give it a poke.

Fortunately I have two inverters and still have my 9.5 battery working fine, but the heat pump and house draw more than my single battery can supply so peak rate import last night which was annoying. Such first world problems

I can’t get the what’s app link to work either - thanks for sharing though geoffreycoan.

After a bit of back and forth with Axle support I am now getting their emails.

And as of the last event (26-Jan), they managed to correctly revert my AIO settings.

Just cleared £50 thanks to signup bonus, a top up and some goodwill credit after I had a moan about taking over my kit without notice and not resetting properly…

And the payout request was instant to my bank account via Stripe and FasterPayments - impressive!

As expected on the 26th as my inverter to battery link is dead.

wrighar £2.95 of export from my single inverter, It all helps. I'm doing far better from Axle than I ever did from DFS sessions, more than £10 this month for sure. I think I'll wait until March when this beta ends to decide what to do with my credit balance. Maybe put it towards buying some more solar panels 😉

geoffreycoan

Is it March 2026? I thought it was 2027... maybe I misread it.

wrighar no it is definitely March this year for the beta programme. Axle have said (on the whatsapp group) that they will be sending more info later in February about what happens post beta.

Presumably the service will continue, I would imagine the £1/kWh and £10/month minimum payment are the bits that change

Would have prefered a working battery and to have generated another _£4.00, bt the top up helps:

I got my email as well today, earning £12.99 in January from Axle

And according to the Octopus app, £3.58 from them for my export, plus a tiny number of Octopoints from the Wednesday DFS session.

All helps, its equivalent to a day’s worth of sub-zero cold winter day’s import

Another session tomorrow (4-Feb-2026) between 8-9am.

I used to be able to find the auction info (e.g. different participants bids & volume, what was accepted etc.) on the NESO data portal, but these don't appear to be DFS events. I'm struggling to find which type of facility/contract this falls under on there.

Can anyone help point me in the right direction please? @hoggy I suspect you might know?

26Left
Bugger, inverter was supposed to be replaced today, but is now being looked at tomorrow afternoon.

So, another session missed.

Successful hands off event for me. (I’m on “event only” mode so Axle don’t manage the charging given I’m on a fixed overnight off-peak tariff.)

• Scheduled timed export 8-9a
• Reset my pre event setting post event.
• was off Eco mode temporarily before and after event (see -ve red tails either side in Power Graph attached).

Given I have an AIO, toggling Eco mode pre and post event seems unnecessary to me, and results in drawing from the grid a bit either side.

Does any know why this is done?

Is it because GE inverters have to be commanded this way to export successfully, and Axle are using a one size fits all command set for their GE portfolio?

26Left Does any know why this is done?

Is it because GE inverters have to be commanded this way to export successfully, and Axle are using a one size fits all command set for their GE portfolio?

I think gen-1 inverters will only export if eco is turned off. But not sure they can claim one-size-fits-all since they fiddle with all the discard slots on my gen-3 hybrid. Perhaps they're relying on the API filtering-out requests that don't exist on the particular target.

Or I guess they could be first requesting the full set of registers available, and then setting those they recognise. (But then they ought to be able to infer that it's not gen-1 ?)

(My own local control script turns eco back on outside of the discharge slot. It used to unconditionally turn it on, but then it was battling with Axle who kept turning it back off, so now I just leave it alone within the discharge slot.)

On a slightly related note, Axle set the discharge slot to end at 9:00, whereas I've found that my inverter continues to export until at least a minute after the deadline, so 8:59 would would better for me - it would discharge until a little after 9:00 anyway (and it's not just incorrect time set on the inverter's clock).

DD

That makes sense - I hadn’t realised that about Gen1s. Maybe they just grab all relevant settings, change what they think they need to make all devices work, and then write back all settings afterwards. Which explains why they have to do it some minutes before and after to get round the entire estate.

Looks like they did a better job of restoring settings : I had setup discharge slot #2 to act as a timed reserve prior to the event, and they cleared it before the event, and restored it afterwards. Though they're still not restoring the discharge levels, which they're leaving at 10.

26Left It's been hard for me to pin down. It's not part of DFS, so it won't show in there.
It's not in anything immediately obvious at all to be honest.
There is only 1 Axle BMU available, but it has been around for some time and has never reported any data (this is how i track "normal" power stations/windfarms.) so it's not done on the more traditional balancing system.
I can't see it under non-bm side of things either (unless it's bunched in with other aggregators)
Neither does it make it's self known in the new Neso Open Balancing System which is where i thought it may reside.

Axle does show up in the Capacity Market registers but this seems restricted to purely EV chargers rather then a bi-directional VPP.

It could even be done down at DNO level through Piclo.

I can roughly predict them based on Margin/LOLP (how much plant is available, less predicted demand) "normally" but today the margin wasn't that thin so this doesn't always work.

If you're on the Axle WattsApp group you'll have seen me point out that NordPool & Epex were both over £100/Mwh which "seems" to trigger them - but not always as we've seen is that the case.

I did have a call with Archy from Axle back in January but he wouldn't let on quite how it works (understandably) but he did however promote my TerraVolt on LinkedIn which was very nice of him. (If anyone else wants to do this then that would be brilliant as it doesn't get as much limelight as the more traditional Gridwatch type ones!)

DD On a slightly related note, Axle set the discharge slot to end at 9:00, whereas I've found that my inverter continues to export until at least a minute after the deadline, so 8:59 would would better for me - it would discharge until a little after 9:00 anyway (and it's not just incorrect time set on the inverter's clock).

I’m sure I read somewhere that there was a built-in time variance in electric meter clocks so even though it may be 9:00, your meter may have it recorded as 8:59 or 9:01. This is to spread load and avoid big grid spikes when cheap periods start.
Maybe this was for economy 7 meters and it doesn’t apply to smart meters?

In the grand scheme of things a tiny bit either side makes no difference either way.

hoggy thanks for such a detailed reply - fascinating. Yes, I’m on the Axle WA group albeit I joined late last week.

I wonder if Axle are running their own private test events and burning through some VC money to further their learning / establish proof points for the next round of investment, propping up user activity and interest levels…

Terravolt is superb and delighted to be a supporter.

hoggy

I've not been able to find the axle WA group....

26Left I have started to wonder this myself. Perhaps it's all just a test right now and there is no real reason, and hence why i simply cant find it!

Perrhaps it really is, "we've just added Fox or Sigenergy or whatever a few weeks back, maybe we should deploy our VPP and see if it works with these new inverters"

wrighar I can't even recall how I got in it to be honest, I think I just randomly ended up in it.

Maybe message the below email and see if you can be added?

there was a whatsapp signup link on the bottom of the ‘welcome to axle’ email. Have to admit I didn’t see it myself the first time. Its a closed community so I can’t generate an invite link, but as Hoggy says, email the above

A good session today, not only did I export about 5.5 kWh with my AIO battery going down to 47%, the battery then fully recharged to 100% via solar.

Event tomorrow at 6pm? Haven't seen an email yet, but my web polling thing seems to have been triggered.

DD yes predbat has just signed me up to it, Tuesday 6-7pm. First evening peak session we’ve had with Axle. The evening Agile import rates for me are only 36.91 and 36.38p and on Agile Outgoing 18.15 and 17.92p, so on those rates, the grid doesn’t seem particularly strained.

And of course I swapped from Agile Outgoing to Agile Fixed last week as solar generation and export is picking up and I hadn’t been getting much of a premium when exporting

If you are not on the Axle Whatsapp group then you won’t have seen this announcement:

Hi there!

Axle is launching a private beta for our new EV smart charging app, and we want you involved! This smart charging app is currently separate from the VPP, but we’re coming to this community because you all have been so helpful in testing the VPP.

We are looking for testers who understand that early-stage software is a work in progress. If you’re willing to provide honest feedback and help us iron out the kinks (and have an EV charger, of course), we’d love to have you on board.

• What we’re asking: Use the app and share your thoughts through our private community.
• What we’re offering: We will pay you £10 per month for your participation. We don’t have specific timelines for the duration of the beta, but we expect it to run for at least three months.
• How to join: Fill out this quick form, and we will let you know if you’re a good fit.

We’ll review applications and reach out to selected testers with next steps.

Cheers!

https://tally.so/r/rjPZ0X

geoffreycoan Hadn't seen that, but I'm guessing probably not compatible with IOG.

MyEnergi are also offering some sort of scheme for Zappi - think that's also to allow backing-off of charging when the grid is stressed.

DD I have no idea, but worth registering interest and see what they say

Just saw this posted on twitter:

geoffreycoan Probably worth pointing out that its not just IOF which precludes the use of third-party DFS, IOG is also affected - ie you cannot use Axle (or any other DFS) if you're on any of the "intelligent" Octopus tariffs. Its in the FAQs/T&Cs.

Vestas

Hmm...

These terms apply to the Intelligent Octopus Go tariff and the Intelligent Octopus Flux tariff - Last updated on 16 Feb 2026 (Version 2.6)

2.4.1.9 By signing up to the Intelligent Octopus Go tariff, you agree to

f) Not enter your Premises into any third party schemes that enter you into a Demand Response Service while you remain on this tariff. If we become aware that you have joined a third party scheme, we have the right to remove you from Intelligent Octopus Go.

Is that a recent addition? Pretty sure I checked before signing up to Axle, and I can't see how I could have missed that.

DD Not recent, been like that for a year or more. Bear in mind that should Octopus choose to then they can back-bill you with SVR for the entirety of the time you've been on IOG.

Its supposedly the core reason why IOG isn't being "subsidised" by all the other Octopus tariffs - if you believe that of course (I don't).

Axle VPP staying as is for now...

Great news, I got the same email as well. Was expecting that the rate or the £10 minimum payment would be reduced, but no. I had been leaving my Axle account balance accumulating, planning on taking it out at the end of the beta, now I'll have to make a new decision 🤔

After this morning's 2 hour power up event (when it wasn't that sunny so I managed to import quite a bit for 0p), got an Octopus DFS saving session today, 11.625p.

Wow.

If I had to make a choice between the two I would go with Axle.

Here if anyone wants it, is my Axle referral code https://vpp.axle.energy/landing/grid?ref=R-VNNIZUYO

Hi Folks, it has been a while 🙂 which means that my AIO has been performing as expected.

I receive an email today from GE Software about GE Premium and although I have little/no need of the GE app these days because I have HomeAssistant and Predbat, I was intrigued by the fact that GE Premium will be at £0 cost to Axle subscribers, so I though I would sign up to Axle and I duly did so

Having signed up and ensured that my tariff details were correct (they had incorrect values, but the tariff structure was fine) I grabbed my API key and configured the Axle component in Predbat as shown below i.e. all I configured was the API key and left everything else as defaults. Did I do it right, or do I need to do something else/more? Since I have predbat, I would like to keep using predbat as my conroller and not surrender this to Axle.

My Axle account is set to "Dispatch Mode - Events Only"

Weasel Should be all good, when an event comes, predbat will pick it up and it will start discharging in that 1 hour window.

arczi19
Perfect - thanks.
I just wanted to be sure I hadn't missed anything; it all seemed too easy 🙂

Weasel that’s all setup correct. What you will find is that both predbat and axle will command a discharge from your inverter when there is an axle event, but predbat’s discharge is usually more precise on starting than axle’s, so you’ll get the maximum discharge you can.

Its good news, I expect there will be rush of people signing up to axle now from givenergy, can see why they have suspended the referral bonus for givenergy customers.

ahem ...... I may have just signed up to AXLE was very straight forward and within seconds I have the premium Givenergy app back up and working.

Really simple process and read all the info they needed from an uploaded bill

Iguana

I did the same earlier and was enjoying the Premium Account which, I have to say, I was quite impressed with.

Suddenly I'm no longer a Premium Account holder and I have no control over my system! Tried the cache, rebooting etc etc. Even tried reregistering with Axle but they at least know I already have the account.

Why am I surprised - It is Givenergy afterall ???