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Dirk-Jan Faber (Victron Energy) avatar image
Dirk-Jan Faber (Victron Energy) posted

Dynamic ESS on VRM

It’s been a long time coming, from now on Dynamic ESS is live on VRM!

2024-05-07: Make sure to check https://community.victronenergy.com/articles/283506/dynamic-ess-green-mode.html too.


What is Dynamic ESS?


Dynamic ESS is an algorithm that aims to minimize the costs made on the grid and battery. It does this by taking several factors into account. First of all the energy price that, in case of a dynamic energy contract, changes every hour. Then it also looks at the solar and consumption forecast. Together with the grid limitations and battery costs and specifications it creates a schedule for the system that determines when to (dis)charge the battery.

Note that the system is not limited to dynamic contracts; it also works for systems that have a fixed pricing scheme.

1710939607755.png

What do I need to use Dynamic ESS?


Dynamic ESS is only eligible for the installations which fits the following criteria:

  • Be an ESS;

  • Not use Generator connection outside of power outages;

  • Has 2-way communication enabled

  • Run Venus OS version 3.30 (or newer)

For best results:

  • Have a variable or dynamic energy contract.

  • Use a supported energy meter (especially if your system setup has heavy loads (EV charger, heat pumps) in front of the Victron system). See here for more information on this.


How can I configure it?


If your site has an ESS, the menu option to configure Dynamic ESS for your site will show. There is a configuration menu that you will need to fill out, before you can actually use it. While we tried to make it as easy as possible, you are likely to do some research in order to fill out all the questions. For instance, you will need to know your battery capacity and the amount of kilowatts it is capable of (dis)charging in an hour. But you will also need to know the formulas that build up the actual price that you pay for buying energy from and selling to the grid. These formulas are not the most straightforward thing to find as the info needed for it is usually somewhere in your energy providers contract.

We provide some example formulas in the dropdown, but that is no guarantee that it matches your actual contract. You need to check that yourself. The manual also gives some examples on how to take the step from your contract to the right formula.

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Known limitations

After this go-live, we will continuously improve Dynamic ESS.


Some of the things on our todo list:

  • Maximizing battery charge by the end of the day to cover consumption until sunrise

  • Periodically fully charge the battery to improve battery life

  • Adding support for varying service fees based on the time of day

  • Allowing users to enter a fixed schedule for grid-battery restrictions

  • Supporting fixed prices that change on the half-hour instead of the whole hour

  • Introducing (smart) support for high-consumption loads such as EV charging and heat pumps


More information


If you need more information, check out the manual. There has already been a lot of discussions on the beta implementation in the comments of five previous articles.


As always, we appreciate your feedback. Feel free to let us know how to improve, and thank you for being part of the development journey. To streamline communication, older posts are closed for comments, and any new feedback can be provided in this post.


When reporting a possible issue, please also mention your VRM id.

ESSdynamic essdynamic
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alex-itcus avatar image alex-itcus commented ·

homeland-vrm-portal.png

Hi, DESS is very frustrating. :))
7 days of trying it made me stop using it.
It has 2 rules it implements all the time that I consider counterproductive:
1. it delays the charging from solar until it is too late and it keeps charging from grid. Most of the time this comes over other surprise consumption - so it never gets the target SOC - hour by hour
2. the target SOC is never achieved in the hour. Even is most of the time less than ”I would do” it never gets ti it even there is plenty solar and no consumption to delay the charge. It does not start charging or it is charging at slow rates (1-4Ah)

This is today and before NOW I started charging it in ESS mode as it was clear it will never get to 100% even in the morning this was the ever to be miss target.

So, it charged many times with expensive grid power with a behaviour like ”UPS, I forgot to charge”.
My MP2 - 5000/48/70 - 5KWh bat - 4.3KW solar on AC-out1 with two 112 (grid and solar)

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

These are all valid points. On the Node-RED implementation we are experimenting with charging earlier and more in the battery while the sun is still out. I expect that to be moved to the VRM implementation within the next 2 weeks.

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

Thank you for the hard work!

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

Perfect looking forward to test it, now I need to turn DESS off because of that. Is there some way to be informed when this change happens? Will it require Cerbo OS update?

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

It is likely only an update on the scheduling side, which does not require an update on the Cerbo. I'll make a new community post when that happens.

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

Any news on moving the Node_RED implementation to VRM?
I truly believe that DESS has a hard time with consumption prediction - it is too exact for its own good. A 20% buffer would work for me way better.
The spring sun added another layer of unpredictability. There is a lot of sun now and current DESS works bad when a lot of sun is available and worse when sun is unstable or different from prediction.
I totally stopped using DESS now after 2 months.

c0619ab55748

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

Any news on moving the Node_RED implementation to VRM?

Yes and no. The Node-RED implementation got an update yesterday morning, which adds a so called "green mode".

If the green mode checkbox has been set, the system will do the following:

  • Only excess solar is fed back to grid - Solar production is only sold to the grid when there is excess after consumption and battery charging;
  • Avoid feeding in from battery - Energy in the battery is reserved for consumption;
  • Use Smart-charging when needed - Charge the battery when prices are low.

Which should result in a comparable behaviour as to set a preferred SOC at a certain time / sunset. We are running that on a few test sites and if the result from that are satisfying, we'll move it to the VRM implementation.
Feel free to switch to that implementation and share the results. There you can use either one of the solutions.

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

Does Green mode means, that it will charge batteries even after target SoC is reached? Meaning the system will plan SoC to be 80% at 14:00 and if the PV is still available, it will continue to charge above this SoC until it reaches 100% and then it will start selling?

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

Thank you for the update! Can't wait to test it on VRM.

Thank you again for your wonderful work and support!

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kositch avatar image kositch alex-itcus commented ·

Me either!

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avukat38 avatar image avukat38 Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

Hello, I want to configure my system but I cannot succeed. First of all, I have the right to sell 10kwh to the grid. My total PV power is 18kwh and I have 25kwh battery. I want my system to work like this: 1st, home consumption, 2nd, selling up to 10kWh to the grid, and I want the remaining PV power to charge my battery. Because when the battery is charged in the morning, more than 10kWh of production is wasted towards noon. If the PV power is sold to the grid for up to 10kWh and charges the battery when the PV production exceeds 10kWh, I will be selling approximately 5kWh more electricity to the grid per day. I think this can be done with the red node, but there is nothing in this regard. I don't know. VRM portal ID c0619ab4d09f

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

Great, I'm looking forward to it!

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

Hallo @Dirk-Jan Faber (Victron Energy)

I activated DESS node red with green mode yesterday evening. So far it's going as I would expect. The battery was prioritized to be charged via PV up to 100%. Then the feed in started. Other aspects like charging from grid at too less PV are hard to test at the moment.
What role do the parameters b_goal soc and b_goal hour play here now? I set both to "0" yesterday.
What would be great now would be a "soft charging" parameter that, depending on the forecast, regulates the charge so that 100% SoC is only automatically reached, for example, after 80% of the sunshine duration of the respective day. So slower charging and less standby at 100%.

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grua avatar image grua ojack commented ·
What would be great now would be a "soft charging" parameter that, depending on the forecast, regulates the charge so that 100% SoC is only automatically reached, for example, after 80% of the sunshine duration of the respective day. So slower charging and less standby at 100%.

Yes, this would be a nice feature, because it's not good for battery health, if SOC is 100% for a long time.

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grua avatar image grua grua commented ·

@Dirk-Jan Faber (Victron Energy) is such a thing planned?

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

Hi,
As time fly I am just curious if VRM deployment of the green mode is closer than 3 weeks ago?
And some questions:
1. DESS is working for me ok if I stop it at 11 and start it again at 16. Is there any chance to have a scheduler as a walkaround for the moment?
2. Away mode - Being away for 2 weeks I have 2 inputs:
a. After a week DESS is working ok in my location when I am away (at almost constant 150-250Wh consumption, just some more for outside lights before midnight and morning) if I reduce the feedin costs 20%.
b. DESS is a nightmare after you come back from holiday as the problems I have with it exacerbate. (keeping battery discharged, no battery charging from solar, charging random at high rates, buy-sell cycles with less than battery cost profit or just loosing money, selling all before midnight then let consume at high rates throughout night and morning... etc)
So, maybe an ”Away Mode” could/would treat this in the future as the algorithm looks like is destroying any hardly earn good experience about the location?

Best regards!

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grua avatar image grua alex-itcus commented ·

About "1. DESS is working for me ok if I stop it at 11 and start it again at 16. Is there any chance to have a scheduler as a walkaround for the moment?"


You can do this easily with Node-RED

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ alex-itcus commented ·
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Gonzalo chain avatar image Gonzalo chain alex-itcus commented ·

I recently activated dynamic ESS. I too noticed some inefficiencies regarding when the system charges the batteries. i have to manually turn it off at time to make it prioritize battery charging and have enough SOC by end of day.I have fixed pricing contract with very advantageous zero energy cost from 23-7am mon-sat and all day on Sunday and very, very high rate outside those hours. I struggle to ensure battery Soc is maintained at sufficient level to ensure minimizing drawing from grid outside those periods, specially when solar irradiance forecast is off which seems to be quite often in my specific area. I must minimize charging from grid outside the above hours.


For example, right now I am selling to grid when soc is 63%. Why? Because forecast says it will be sunny later in the day but weather today is unstable and that forecast will probably be off. Regardless, what’s the point of not charging when having excess solar. It should be charging battery when any excess energy is available and sell to grid only after target SOC is reached which for me should be 100%. I understand there is some “cost” on charging/discharging battery on cycles used but would like some fixed rules capabilities like (never sell if target soc is not reached and excess solar is true)

img-3856.jpeg


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markfrencken67 avatar image markfrencken67 Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

Hi, I'm suffering from the same issue as a lot of fellow Victron users here, solar energy generated at the AC in side is not 'recognized' in the algorithm it seems. Is the (hopefully adaptable' node-red implementation still around?

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kositch avatar image kositch alex-itcus commented ·

I totally agree, there should be option to prioritize battery charging to desired SoC or just "full" before selling the PV Power to the grid....

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grua avatar image grua kositch commented ·

At the very least, the priority in the planning of the DESS should be fundamentally changed so that the battery is always charged first and PV surplus is always sold afterwards.

This is currently planned the other way around. DESS often sells first and then only charges the battery towards the end of PV production. This can result in the need to recharge from the grid towards the evening if PV production in the afternoon is lower than forecast.

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alex-itcus avatar image alex-itcus alex-itcus commented ·

Discovered that turning off DESS when the sun shines makes the whole system work great!
So DESS worked for one hour (9to10) as it should: supporting consumption and charging from solar. Then it idled the battery at 19% and start exporting to grid at 10:01. Between 10 and 11 it was supposed to charge 0.33KWh from solar even that the solar produced only in the first 30 minutes more than 1.6KWh. The battery was idle for the first 30 minutes, moment when I stopped DESS.

Funny side appart, does anyone now on how to automate this until DESS is unbroken? Maybe DESS is made to work only without solar at this point?

homeland-vrm-portal-1.png

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alex-itcus avatar image alex-itcus alex-itcus commented ·

The plan looks totally wrong. We have 7.1 kWh forecasted but only 0.6 for battery charge

1. solar forecast is most of the time 50% less than reality

2. battery is not charged even with the small amount scheduled as it is kept idle

3. the solar is wasted on grid even I have zero euro for selling (!) and zero on battery cost.

As you can see in the plan, the battery is supposed to be charged with 2.5kWh from grid wasting all the surplus solar that do not fit to the plan.

homeland-vrm-portal-2.png

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grua avatar image grua alex-itcus commented ·

As Dirk-Jan mentioed here, this should be better in some weeks:

https://community.victronenergy.com/comments/272031/view.html

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john245 avatar image john245 alex-itcus commented ·

@Dirk-Jan Faber (Victron Energy)

Energy prices including taxes are negative in the Netherlands between 13:00 and 14:00. However costs are displayed in the chart.

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ john245 commented ·

That looks like a graphing bug. Thanks for reporting. We are looking into that.

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ronaldt avatar image ronaldt commented ·

I did not receive an update today regarding the day ahead prices. Am I the only one?

It is 19:37 so the should have been there. Is there a way to actively pull them?
schermafbeelding-2024-04-04-om-193536.png

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zonnigbreda avatar image zonnigbreda ronaldt commented ·

Here the same... I assume something went wrong in the dataload today. But it begs the question, is there some auotmated refresh happening in this case so the situation corrects itself?


As tomorrow there are negative prices for me, it would be bad timing if I miss ' the free meal' .
Anyway, I saw it by accident thatit is not available, but I hope this is a ' set and forget' sort of thing, not something I need to monitor daily.

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Jeroen Peters avatar image Jeroen Peters ronaldt commented ·

Same situation here. Auction outcome on EPEX website is published 12.45h. Victron should be able to push them at 13h or 14h latest. Especially when high prices next morning sometimes provide the opportunity to charge a bit more still.

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sni avatar image sni ronaldt commented ·

Same here on stable and Beta OS installed. I Hope for 1 pm.


Id c0619ab0f3ad

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gdhondt avatar image gdhondt commented ·

Dear Victron team.

Frank energie/Bliq and zonneplan are offering ESS system from different brands which are compatible with trading on the “onbalans markt” this would also be a huge benefit if Victron can provide this function in cooperation with an energy supplier.

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john245 avatar image john245 gdhondt commented ·

I know Tibber is investigating if they can add Victron.

People are earning > Euro 200,- last month on this market. Very interesting and would be a good selling point for Victron.

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Enya Salida avatar image Enya Salida commented ·

I'm sorry having to confirm some of the often mentioned issues and I turn off DESS for now. The biggest problem for me could be solved by a simple additional rule:

  • never ever feed any power into grid if the battery still can take it!

This must be obeyed if “Can you sell energy back to the grid? No” is selected and also if you can sell, at least in Germany feed in rarely is a better deal than storage and self consumption.

Also annoying: if I switch on high loads like washing machine or heat pump for hot water intentionally in times with very low prices I don’t want them to be supplied from battery – which will be recharged afterwards at higher prices – at least if not very much solar is expected.

I’m sure the calculation of the optimal SOC for every hour with unpredictable conditions is not easy to do and I thank Victron Energy and Dirk-Jan Faber very much for this development!

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Gonzalo chain avatar image Gonzalo chain Enya Salida commented ·
This could be solve if they implemented some fixed configurable rules to work in conjunction with dynamic ESS. I would also like to have this capability without having to turn off the complete dESS
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meyo084 avatar image meyo084 commented ·

Hi, quick finding.. dyness ignores max charge and discharge at the moment.. anyone got the same?


Site c0619ab38e24

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Jeroen Peters avatar image Jeroen Peters meyo084 commented ·

Yes, here is also seems to go at DCL instead of de discharge power set in the Dynamic ESS settings.

VRM ID: c0619ab4b45a

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axel-koning avatar image axel-koning meyo084 commented ·

I am on 3.30 since yesterdag. Also discharging to bms limit of 150A instead of 5kW battery limit DESS.

Also in Cerbo feedinlimit shows always active, also when switched off

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Dirk-Jan Faber (Victron Energy) avatar image Dirk-Jan Faber (Victron Energy) ♦♦ meyo084 commented ·

Have you read https://www.victronenergy.com/live/drafts:dynamic_ess#qwhy_does_the_system_exceed_the_configured_power ?

During the configuration of the system, you are setting the capacity of the system, not the actual limits of the system. These capacities are used by the system to make its calculations, so it used as an average power the system can do in an hour.

If you need to limit the import configured power, you can configure import and export AC current limits via the Settings → ESS menu in the GX.

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

That's strange, because it used to work properly during the Venus OS 3.30 beta phase. It would calculate a SOC target based on the DESS power input and charge of discharge at the power to get to the target by the end of the hour.

Moreover I don't want to use the peak shaving function to set my battery optimization limits. I want to peakshave based on the maximum current my grid connection can handle which is much higher than what I want to use for trading energy.

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

If I recall correctly, the (dis)charging became a bit more aggressive in one of the more recent beta updates. With the reasoning that it is better to reach the target early than not at all during an hourly slot.
But we will take a closer look at both sites to check if some adjustments need to be made.

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

Hello, Jeroen is right. The DESS limits for trading has to be fully respected. The ESS limits for grid feed-in and import current should be used only in case that battery is 100% to avoid PV power reduction or in case low SOC and high power consuption.

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

It seems to be very aggressive indeed, going over by more than 50% which is also bad efficiency wise.

Shouldn't DESS (dis)charging be limited by it's setting? That seems the most logical.

If target is not reached within the hour it should be due to a wrong assumption on battery capacity or (dis)charging efficiency, right?

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pim57 avatar image pim57 Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

I think the discharge is way too aggressive. In the configuration I set 2.5 kW as a discharge limit because of the 94% efficiency. With this modulation method the efficiency drops to 89%.

I switched back to ESS for the moment.

img-0734.jpeg

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Peter avatar image Peter pim57 commented ·


ESS is controlled by GbbOptimizer :-)

GbbOptimizer respects all limits!

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Barbara (Victron Energy) avatar image Barbara (Victron Energy) ♦ pim57 commented ·

Hi, DESS uses the max (dis)charges for making schedules, but for strict limits, it depends on the battery's capacity. So you might want to review your set battery capacity in the configuration.

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meyo084 avatar image meyo084 Dirk-Jan Faber (Victron Energy) ♦♦ commented ·

So if I understand correctly, do I now need to make a setting in my Cerbo to achieve the same result for a function that worked fine during the beta period? However, do I need to purchase a Victron-approved meter for this? And what are these limits in the DESS settings still used for? The system worked perfectly for me until it transitioned to production.

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delusional112 avatar image delusional112 meyo084 commented ·

Same here, I have DVCC on max 210 amp. And the settings in DESS on 6 KW. Then it discharges over 270 AMP and I get overload warnings on the phases.



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electronicsuk avatar image electronicsuk commented ·

I tried Dynamic ESS on Beta a couple of months ago but as it kept exporting PV instead of charging my batteries, I switched it off. Today I updated my GX to the latest firmware, updated to the latest ESS assistant and re-enabled Dynamic ESS. I can't understand why, when I get paid nothing for export, DESS is exporting 1300W to the grid rather than using it to charge the battery. Yes, there is plenty of PV forecast for later in the day, but what if the forecast is wrong? Why waste all that power?

1000013562.png

Even stranger is that the battery is lower than the target SoC, so I'd expect it to be charging right now. Unless 62% is where it wants to be at the end of the hour?

1000013560.png

I'll persevere with it for a few days and see how things go, but when import prices are high all day and export is not paid, surely the goal should be to hit 100% battery charge as soon as possible? Then, if PV output is lower than forecast or loads are higher than forecast, there is some spare change in the bank, so to speak!

1000013561.png


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kositch avatar image kositch electronicsuk commented ·

It behaves exactly the same for me, even when I set export price = 0 it sometimes during day (usually at the beginning) start selling the PV power to the grid even though battery is discharged to 40%. I have some rules to power on water boiler when battery SoC exceeds the 93/95/97 % of SoC (each level for each phase) so I would preffer DESS to charge the battery "full" before doing any export to the grid. I dont wont to turn off the grid export, because when water is heated and battery full I want to sell electricity, but only in that case. Not sure if there will be some change in future tu enable this. I know a lot of installations, when they cant use DESS because of this behaviour of "not charging battery to full" as the priority :/

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electronicsuk avatar image electronicsuk kositch commented ·

This evening it's even charging from the grid at peak rate, because the plentiful solar during the day wasn't put into the battery. It's exactly the same problem as in the beta release. I'll see if @Dirk-Jan Faber (Victron Energy) has any suggestions but if it keeps doing this after a couple more days then it's going to have to be switched off and I'll go back to scheduled charge levels, as at this rate it'll be costing me more running DESS than without it.

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kositch avatar image kositch electronicsuk commented ·

Yes, same for me, not sure if I have something wrong, but it sells at the beginning of the day the PV power instead of storing it to batteries and when sun goes down during the day and battery is not charged at the target SoC it start buying expensive energy in the evening to charge the battery :-(

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

By the looks of it you've now set "Can you sell energy back to the grid?" to no, which would be the advice I'd otherwise have given you.
That being said, I've made a not that we should make a more clear setting for this type of sites.

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

Thanks! For those of us who don't get paid for exporting back to the grid, the priorities for DESS should be:

  • Put all excess PV into the batteries
  • Don't care too much about meeting a specific target state-of-charge level when discharging, it's better to empty the battery than buy from grid at high rates
  • Only use the grid for charging during cheap rates, and leave enough space in the batteries for tomorrow's forecast PV.

Of course, I appreciate that's easier said than done as everyone has their own wishes for how DESS should work!

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

I have the exact same Problem as @kositch described. Solar Energy is feed into the grid in the morning when SOC is at ~40% and later on the same day Battery is charged from Grid for 2 or 3 times of the Price of the Solar Power... I just don´t understand the calculation here. is there maybe a problem with smaler installations around the 5kwp Solar power and 4.8 kwh Battery size? (My VRM ID is 48e7da891c1f)

Your Advice on turning off "sell energy back to grid", will that completly disable feeding into the grid or just removing it from calculation? @Dirk-Jan Faber (Victron Energy)


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grua avatar image grua karkas commented ·

As Dirk-Jan mentioed here, this should be better in some weeks:

https://community.victronenergy.com/comments/272031/view.html

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alex-itcus avatar image alex-itcus commented ·

My last 7 days experience with DESS on Zonneplan with a 5KWh battery was very frustrating. I gave it a chance to be better every day, hopping. Unfortunately it sticks to some (bad) rules:
1. It sells to grid solar most of the day delaying battery charge. From the first day I disabled the sell price and battery cost hopping to start charging the battery sooner. Not a chance.
2. It starts the charge of the battery mostly in the last 2 of sun hours even if it is obvious it will not be able to charge to 100%. Even so, during those hours is charging at random speeds (1-3Ah at times, even idle) and at some point it goes on full throttle. Then as the price gets up and as soon as the sun goes down goes full charging at the high price from grid.
Like ”Uuups! I forgot to charge!”
Ex. A day with 5 hours at 18c and full solar charged 0.4 on solar all day then at the end of the day 3KWh from grid at 24c then 26c just to discharge them in the next hours at 26-28c.
My system: v3.40~1 MP2 48/5000/70 - 5KWh battery - 4.3KW solar - 2x 112 sensors one for the grid and one for the solar on AC-Out1


Today the initial plan was to sell at 0 cost solar to grid (!) and delay start charging around 13:00 and go 55% and so on, all the time less than the 2Kwh per hour limit I set. Now, after 15KWh of solar sold to grid it kept the battery at 34% until 15:00. It was obvious the battery will never be charged and I will pay the full price of 0.37 for the evening so I disabled DESS and start charging the battery on ESS mode.

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grua avatar image grua alex-itcus commented ·

I also think at start of solar production FIRST the battery should be charged, and AFTER this PV surpluss can be sold. Not vice versa.

I also observed this very often.

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mryoshii avatar image mryoshii commented ·

Am I understanding something wrong?
DESS is not charging at the lowest price. It also shows solar to battery, even tho I don't have solar installed at the moment. I will keep monitoring the situation, but this doesn't seem right.
1711455699244.png

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mheinze5722 avatar image mheinze5722 commented ·

Right now it seems the algorithm strictly optimizes to reduce cost, as exemplified here:

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Right now, it really optmizes a single day for reducing cost and optimizing revenue: and of course that means, exhaust the battery to the minimum of 15% SOC at the end of the day. But that is not what I want. It misses the rest of the night (which it will probably only add 'in scope' once rates are out at around 2 pm) - but then it is too late to fully charge the battery. Also, I want the battery usually rather full instead of just charging the minimum to be better prepared for grid outages or occasionally higher consumption over night.

As such, I (as a house owner; boat, RV, commercial or industry could be different) would like to see my LFP battery to rather charge to 100% every day (NMC could be 80% charge goal in warm&sunny months), and charge slowly to extent battery life and reduce midday-feed-in-peak.

As such, the goal should be extended to:


Dynamic ESS is an algorithm that aims to minimise the costs made on the grid and battery, based on following expectations:

- aims to charge the battery every day to "Default Charging Limit" [LFP=100%, NMC warm&sunny=80%]

- Aims to charge the battery until after midday-peak to slow/steady battery charging for battery longevity, reduce midday-feed-in peak and reduce AC->DC conversion losses.

- Aims to hold the battery SOC level rather higher than lower, for situations of grid outages and unexpected (higher) consumptions.


Thanks for reading, Michael

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kositch avatar image kositch mheinze5722 commented ·

Yes same for me, there should be some option to request charging battery to full each day if PV is surplus, because I know a lot of installations where customer requested turning on AC2 out based on SoC criteria to heat the boiler from PV energy which would be sent to grid and if SoC will not reach above that SoC it will never turn boiler on and instead of it it will sell the energy, which I dont want to disable because when boiler is heated up, I want to sell it. Not sure how to handle this, something like "sell energy but only when SoC of battery reaches 100%" or something like that for those who use surplus PV energy to store to the boiler....

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nwametze avatar image nwametze commented ·

About the menu-option ‘Self-consumption from battery' with the choice ‘all system loads’ or ‘only critica loads’.

Wondering why an external energymeter is mandatory if the multiplus is connected between grid and all loads. The multiplus does measure all values, so why the need for an external energy meter before this option in the menu becomes available?

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