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Barbara (Victron Energy) avatar image
Barbara (Victron Energy) asked

Dynamic ESS: Introducing fixed price slots of 30 minutes

We are happy to announce that Dynamic ESS now supports fixed prices set to 30 minutes slots.

In countries like the UK, energy prices vary as much as every 30 minutes. To facilitate for this, you can now set up a fixed price schedule using half hours. To try this out, open Dynamic ESS settings in Victron on Beta VRM. Select fixed prices for selling and/or buying energy. Fill out a time slot for 30 minutes in which the price varies. From now on, your Dynamic ESS schedule for consuming, selling and buying energy will be adjusted to this entered schedule.

For UK users that use dynamic prices, we are still working on adding those. Expectancy is that this will be ready at the end of June.

Update 2024-06-17: We've moved this to regular VRM.


screenshot-2024-06-04-at-165843.png

dynamic essDESSfixed priceuk
screenshot-2024-06-04-at-165843.png (57.7 KiB)
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Ants Kosmos avatar image Ants Kosmos commented ·

In Estonia we have different taxes for day, night and weekends with dynamic electricity prises. Good to know if this possible use in formulas . :D

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John Dent avatar image
John Dent answered ·

Ooo this is great news!

Out of interest, can the slots be filled in with a POST request?

I’m thinking some quick (and relatively dirty) Node Red flow to take Octopus’s 30 minute slots and post them into the VRM DESS web form.

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ commented ·
This should be possible from next week. I'll post an article then describing on how to do just that.
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John Dent avatar image John Dent Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

Saw your article. It didn't precisely explain how to set the price slots, but it seems to work so I hope that's the intention. Great stuff — can finally teach DESS about Octopus Agile rates!

In case anyone is wondering, it's simply a matter of poking the Modify DESS config node with a payload of { "buyPriceSchedule": <new buy price schedule> }.

It grumbles if you give it an incomplete schedule, which is slightly annoying. So that means you have to install it at a time when you still have at least a full day's worth of 'runway'. (That or make up placeholder rates, which is a bit weird.) It is workable, even if not quite ideal. I'll report back if any issues.

Thanks!

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ John Dent commented ·
Getting the JSON right might be a bit tricky, but that should indeed work.

We also got preliminary support for the dynamic prices of Octopus on our test setup since yesterday. Let me contact you directly to check if you want to be the first to run that.

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fellside avatar image fellside Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

Where can we find the article you mentioned?

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daniel-feist avatar image daniel-feist fellside commented ·

Pretty sure it's this one: https://community.victronenergy.com/content/kbentry/293324/node-red-vrm-api-and-dynamic-ess-1.html

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daniel-feist avatar image
daniel-feist answered ·

This is welcome progress, but I personally still find that DESS doesn't behave as expected and therefore isn't usable.

As a concrete example, my export tarriff is 15p 24/7 and between 23.30->5.30 my import tarrif is 7.5p but DESS "trade mode" doesn't:
- Sell to the grid prior to 23.30 even when it is clear there is a profit to be made given the upcoming cheap import tarrif.
- Fully leverage cheap 7.5p overnight import to charge battery when this is a no-brainer. Instead it relies on unreliable PV forcasts for the following day and only partly charges overnight (if at all). Then, if the sun doesn't shine as expected, it imports at 30p/kWh (four times the price).
- Prioritize charging battery with PV to cover evening forcast usage. Instead, it first exports and only later in the day charges the battery. This means that, if PV generation doesn't happen it will import in the evening at 30p/kWh when it shouldn't need too.
- Use only grid for consumption during cheap 7.5p rate. Instead it consumes from battery for some strange reason some of the time.


Before there was some discussion of some of the oustanding issues being tackled. But was there any progress on any of these?

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frantiseksobotka avatar image frantiseksobotka commented ·
Hello, you are right. DESS is also from my point of view not usable.

Issues which are/were reported are still pendling and green mode neither node-red version not solved most of the problems till now.

I tried personally 4 different ESS optimizers. Victron DESS, Victron node red DESS, one optimizer made by Czech company and one made by Polish programmer, you can now him from this forum.

Unfortunatelly Victron DESS is the worst and best one which I am using is the optimizer from Piotr Maciejewski. It is a bit user unfriendly at the beginning, but when you have setup done, you don´t need any more daily or hourly babysitting of your system. Just setup and forget. With full control of all the parameters.

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daniel-feist avatar image daniel-feist frantiseksobotka commented ·

I am also using gbboptimizer (I didn't see the Czech one though). Works great for me too, even though I agree it was initially somewhat complex. However, every time I see a DESS announcment I test it again just in case I'm pleasantly suprised. Every time though I see the same issues again. (I just added one more to the list above that happened last night)

If you are on fixed tariff, green mode is no different to using ESS + scheduled charge is it?

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frantiseksobotka avatar image frantiseksobotka daniel-feist commented ·
Same for me :) I tried it yesterday and have to switch off after one hour.


DESS just finished 6kW grid feed in and just afterwards started to buy 6kW expensive grid to push it to battery during nice sunny PV 11kW production when over max 100% was predicted for afternoon.

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frantiseksobotka avatar image frantiseksobotka daniel-feist commented ·
Yes, green mode is ESS with automatic charge at low price (which I do not need 10 month).


The biggest DESS problems for me are: unwanted feed-in followed by charging and not possibility to trade to defined SOC only and use rest ot battery till minSOC as buffer.

Both are solved at gbboptimizer.

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ commented ·
Lets see if we can get this working nicely for you then. First of all, I notice that on your site (assuming that is c0619ab38079) your currency still is set to Euro. Under Settings -> General -> Currency, you can set that to be Sterling.

The maximum import power and maximum output power are also set quite high, or at least higher than I would expect. What is the amperage of your main breaker?

Also your points 1 and 3 seem to clash. In order to mitigate point 3, you'd better switch the system to "green mode".

The system also needs a bit of run time (a few days) without too much tweaking. And your system hasn't been running long stretches for a while.

A colleague also took a look at your system to check why it didn't charge. And he did discover a bug in the system, when the sell price was higher than the buy price. He fixed and released that. So that shouldn't happen again.

Then about gbboptimizer. Feel free to switch to that if that works better for you. I don't mind at all (as long as you use Victron equipment, I am happy). I am personally perhaps a bit hesitant on letting a third party take control on my system. But I am probably more paranoid than most users.
But I did take a look at gbboptimizer a while ago and I found it quite complex to setup. The more settings you can do, will certainly help in getting the optimal results. With the VRM implementation we try to get the best results with minimal adjustments needed in a user friendly way.

Lastly about "outstanding issues being tackled". That is a bit of a general remark, so I'll answer it a bit generic too. We did close a lot of those tickets in the last months. So yes, there is progress and no, the todo-list isn't empty yet.

And please do keep reporting issues; the more concrete, the easier it is for us to look into and to find a cause and solution (dates, times and vrm ids help a lot on quickly troubleshooting). I try to read all messages and react to a lot of them. But as this is quite an active topic I am sure I'll overlook some posts. All time I spend on community is time I don't spend on coding.
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daniel-feist avatar image daniel-feist Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

Appreciate your detailed response. Yes. c0619ab38079 is me!

  • Fixed euro->sterling, didn't find setting before.
  • Max import is 3x100A (three-phase). Max export (approved) is 22.1kW.
  • Max discharge is based on 4.4kW/phase. Max charge is more than 5kW, but I limited this before to be kinder on battery.
  • 1 and 3 don't clash. They are different issues, they wouldn't happen on the same day:
    • 1 is about selling for 15p in evening when you know you can buy back for 7.5p overnight. If you are in "trade" mode this should be obvious thing to do. This is more an issue in summer, in winter you would likely not have exess in evening with heating on (at least with my battery capacity).
    • 3 is about the approach used to charge battery from PV to allow for evening usage. This is more important in winter/spring/autumn when there is less PV (and when cheap energy that charged battery overnight may have been used for heating). If DESS knows (based on forecast) that 50% charge is needed for the evening, it has a choice. Either i) charge to 50% from PV and then export ii) export and then charge to 50% in the late afternoon. Currently it is doing ii) and the risk of this approach is that weather may change, cloud might come out and it can't charge to 50%, and then import is required in the evening. It is best to take the more conservative approach and it reduces risk of expensive import and don't reduce profits. Others have also raised this.
  • Do you have any details on the bug, what it impacts specifcially and what release it will be fixed in? If the system was getting confused when sell price is higher than buy price that could explain a lot!!
  • I am open-minded as to different solutions. GbbOptimzer is definitely a steeper learning curve vs DESS and I avoided it for a long time. Eventually I took the time to onboard because DESS (previous versions) was actually loosing me money. That said, the reason I keep coming back to DESS and trying it again is because I really believe that Victron (via firmware updates and introduction of core functionality) has the ability to provide the best solution e.g. via min/max-setpoints etc. I'm not yet seeing this though.

I undestand progress is being made and that's great, this is really appreciated. Just since it came out of beta, there seems to be a less visibility of whats being improved/fixed and I wasn't sure if/when I should come back and re-test it.

I'm happy to keep DESS enabled for a few days without touching anything if you have someone looking at my install. It will be interesting to see how many of the 4 issues I mentioned are fixed by the bug you mentioned. The PV charge/export priority I thought you mentioned was in node-red version already, is this correct? When will this make it into VRM version?

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daniel-feist avatar image daniel-feist daniel-feist commented ·

The plan looked better, so it seems the bug you mentioned is fixed. Although ideally:
- Discharge should happen later in the evening to be more conservative
- Discharge should be more gradual, not 11kW which is less efficient. (I can limit charge/discharge rate, but shouldn't really need to

1717779978436.png

BUT, in practice the there was was minimal discharge and the new plan now doesn't have discharge.

1717779944586.png

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Galin Radoslavov avatar image
Galin Radoslavov answered ·

Hi,

This is a good new BUT when you will fix the diagram for BULGARIA?

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Related Resources

Dynamic ESS beta discussion

Dynamic ESS GitHub 

Dynamic ESS DRAFT documentation

End user custom DESS implementation (Andy156) 

Dynamic ESS - manual

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