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Dirk-Jan Faber (Victron Energy) posted May 7, '24

Dynamic ESS: Green mode

Hi community,

We’re excited to introduce a new feature on VRM Dynamic ESS that makes Dynamic ESS more flexible for different use cases: Dynamic ESS Green Mode. This mode is designed to prioritize self-consumption within your battery system while ensuring surplus solar energy is fed back into the grid. Here’s a breakdown of how Dynamic ESS Green Mode works:

Optimized Self-Consumption: With this mode enabled, your system first directs solar energy towards meeting your immediate consumption needs.
Battery Charging Priority: Once your consumption needs are met, any excess solar power is utilized to charge your batteries, ensuring they are charged sufficiently for hours without solar.
Grid trading: Only after your consumption and battery charging needs are fulfilled does the system consider selling surplus solar energy back to the grid.

The aim of Dynamic ESS Green Mode is to maximize the use of renewable energy within your own setup before considering energy trading, promoting greater energy independence and reducing reliance on the grid. To explore how Dynamic ESS Green Mode can benefit your setup, navigate to the DESS settings and enable this feature.The current mode of Dynamic ESS, trade mode, will still be available. Trade mode considers the economic benefits of selling to the grid versus self-consumption. In doing so, if selling back to the grid is more profitable than charging a battery, it will opt to feed back into the grid. Whether you choose Dynamic ESS Green Mode or Trade Mode depends on your priorities and economic considerations. Both modes offer unique benefits tailored to different user preferences and scenarios.

You can find it in the Dynamic ESS settings under the system section.

We encourage you to experiment with both modes and share your experiences with the community!

Also, when running Dynamic ESS, please make sure to either update to v3.31 or to run the latest candidate release, if you haven't already.

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ronaldt commented · May 07 at 08:56 PM

Thanks! Another nice step forward in the functionality. That is what this system makes great. Constant improvement and good feedback from an active community that helps to improve the product.

I have used Green Mode already a couple of times via Node Red. But my first point of improvement would be to at least sell back to the grid when the price is high. That is not happening now. See graph below where the system sells just after the peakprice. And this has happened more then once.

Where Green mode is sort of trying to have my batteries full and only exports to be able to store my solar energy expected the next day in the batteries, trade mode is trying to sell/export all my energy. So we go from one side of the spectrum to the complete other side. It would be nice to have a sort of aggressive factor in the system. Where you can slide between Green and Trade mode. I do not want to trade a lot to only gain a few cents, but I have no real control over that now.

See below the example where at 19 and 20 price is maximal, but export only starts at 21. Batteries were already completely full at 19.

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ojack commented · May 08 at 08:57 AM

Thanks a lot! Green mode is exactly what we need in Germany.

Next winter will show if charging from grid at lowest price as much as necessary and as little as possible will work too.

Three improvements come to mind:

1. Charging slowly if PV forecast is much higher then consumption forecast to protect the battery by means of lower current and less time idling at 100% SoC. These day battery is full at 9-10 if not reducing the current.

2. Some kind of advanced battery life which only charges to for example 90% (user defined) all day if sufficiant. And charging to 100% once a week for balancing.

3. Prioritizing battery charging over mppt because of better efficiency. Up to charging only via mppt if the solar forecast DC is sufficient for reaching target SoC until maybe early afternoon.

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electronicsuk ojack commented · May 08 at 09:57 AM

I think #2 is already being worked on by Dirk and the team. I don't agree with #1. Priority should always be to get batteries charged as soon as possible in green mode, because you don't know if the PV and/or consumption forecast is correct, so better to have plenty of charge 'in the bank'. If you're worried about battery life then you can always set a charge current limit to apply at all times.

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ojack electronicsuk commented · May 08 at 12:19 PM

#1 I agreee with you that charging battery should be at high priority. But I mean with a good amount of security buffer the system could do some smooth charging. Reducing the current would be one simple way. To combine security and less time idling at 100% two steps charging could be another way. Charging higher or full speed to 80% and later to 100% for example.

At the moment even with an error of 80% in PV forecast the battery would get full enough. At this screenshot I used only 1/3 of my PV (only the mppts) to charge the battery. Nevertheless the battery was full at 12.

But of course this is all optional and depends on the size of the PV and battery.

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grua ojack commented · May 10 at 09:23 PM

@Dirk-Jan Faber (Victron Energy) Green Mode is a big hit, now DESS is where it makes sense for me to leave it on permanently! I would like to thank the whole Victron team for this - I've had it active for a few days now - absolutely great work!!!

Of course, there are always suggestions for improvement. And from my point of view:

The point mentioned by @OJack "1. Charging slowly if PV forecast is much higher then consumption forecast to protect the battery by means of lower current and less time idling at 100% SoC. This day battery is full at 9-10 if not reducing the current.":

For LiFePo4 it would be much better not to be fully charged for too long. However, the planning for the day before yesterday in Green Mode was as follows:

I have therefore implemented in Node-RED that CCL is limited to a lower current value above SOC 80%, but if the storage is not yet full 4 hours before sunset (and also in the event of lost grid), CCL is lifted again. This means that 100% is only reached in the afternoon and the battery does not remain at 100% for too long. Here the resulting SOC curve for the day shown above:

The big disadvantage, of course, is that my Node-RED Flow is only a very rudimentary solution that takes no account whatsoever of solar and consumption forecasts.

It would certainly be a big step forward to implement a function such as "Reach 100% safely, but only remain at 100% for a short time".

But as I said, this is just another suggestion for improving DESS Green Mode that now works very well!

thx a lot for your great work!

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kudos50 ojack commented · May 08 at 09:37 AM

You have my vote for #3 but it seems the votes and suggestions are scattered all over the forum. I tried to put something together in the DESS forum but had no responses at all :-)

Anyway. I will simply continue my quest by finding all of them and replying until Dirk-Jan gives in!

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ojack kudos50 commented · May 08 at 12:22 PM

I'm sure Dirk-Jan reads the comments. But I'm also sure he has a long list of ideas for improvement to work through. And at the same time, DESS should not become too complex and remain user-friendly.

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Johan commented · May 09 at 10:43 AM

Hi to all,

Greenmode is nice a big improve, for me at least. But it would be nice, that the system still could deliver back to the grid when the price from grid is high, and soc is above a set value.This will be useful in summer when batteries are full from solar. In the evening / morning empty batteries when price is high, and overday charge again.

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frantiseksobotka commented · May 07 at 06:30 PM

Hello,

that is great news. We expected step forward already long time.

So let's test it!

Can you please later share more details about all new adjustment of the system for the green mode?

Is there also any modification for the trade mode?

I just switch on green mode. The planning looks fine, tomorrow trying to fit a single point to 100%. What I see also that now at evening it follows also my ESS grid set point -200W, is that right that grid set point is considered by DESS already?

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ronaldt commented · May 08 at 03:40 AM

When switching between Green mode and Trade mode the save button is not activated (Verzend in Dutch). Only when you change something else on the page, you can save the settings.

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Barbara (Victron Energy) ♦ ronaldt commented · May 08 at 06:14 AM

This is a known bug on BETA. Could you confirm that on production VRM you don't encounter the same?

We will fix the BETA bug today.

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grua commented · May 08 at 06:25 AM

Thank yo so much for this great feature!!!

I'll test it!

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zonnigbreda commented · May 08 at 07:18 AM

first of all: Great enhancement!

I find the first lin of the description in the " Trade Mode" box rather wrong, or at least put you off in the wrong direction.

It suggest indeed you always sell your suplus solar back to the grid, which unless you know the system better , gives the idea that solar is sold directly (e.g. even if the price is negative)

I think the consfusing word is "always", whereas in the desciption in the post it is more nuanced: "if selling back to the grid is more profitable than charging a battery"

Trade mode considers the economic benefits of selling to the grid versus self-consumption. In doing so, if selling back to the grid is more profitable than charging a battery, it will opt to feed back into the grid.

Would suggest to improve the text in the box. e.g. "Sells surpluss solar back to grid if more profitable"

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Barbara (Victron Energy) ♦ zonnigbreda commented · May 08 at 03:17 PM

Thank you for this suggestion, I will change the text!

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electronicsuk commented · May 08 at 08:15 AM

Hi Dirk. I've been awaiting this for a while. Thanks again for considering us users who aren't paid for export. Sadly, it's still not behaving as expected for me. Switched on Green Mode this morning and my system is exporting even though the batteries are nowhere near full.

I checked the batteries and the charge limit is 240 Amps so there's no reason not to be charging them when there's plentiful PV. Seems like Green Mode is still too concerned about maintaining a set battery level instead of filling the batteries as early as possible?

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Dirk-Jan Faber (Victron Energy) ♦♦ electronicsuk commented · May 08 at 08:28 AM

One of the things I noticed on your system is that you have your PV inverter on the AC output side. Please update to v3.31, as there is a bug in v3.30 that is affected in this combination. I'll update the above post to also mention this.

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avukat38 Dirk-Jan Faber (Victron Energy) ♦♦ commented · May 08 at 08:46 AM

Is this the logic of the trading mode? PV is primarily for use, the excess is for sale to the grid, the remaining for battery charging. If so, that's exactly what I want. before selling to 10500W mains, this is great

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electronicsuk Dirk-Jan Faber (Victron Energy) ♦♦ commented · May 09 at 09:58 PM

Since updating to the latest firmware it's working well! Because the weather is so nice, I haven't had a day yet where there was any need to top up from the grid on cheap rates overnight, so I can't say how well that bit works. But the fact that I've not taken any energy from the grid is a big improvement over how well older versions of DESS were working!

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eamonpendergast commented · May 08 at 04:03 PM

Nice to see new options rolled out for DESS! I'd like to echo the comments of some, both extreme cases are covered, but there's no middle ground.

In Ireland, there's an unusual Usecase; fixed rates 24/7 for selling to the grid (25c/kWh), high day rates (37.5c/kWh) and highly reduced night rates from 2am-5am (5.5c/kWh).

Other considerations are my peak generation ability is ~11.5kWh, but I'm capped to 5.5kWh when selling to the grid. So if my battery is full and house consumption is low, I'm not able to fully utilising the system.

Both algorithms struggle to manage this well.

With Green mode, looking at the schedule it produced, it basically always charges the battery to 100% as fast as possible and then begins selling back. This risks poor utilisation by hitting against the 5.5 kWh cap when the batteries are full and the sun is out.

With Trade mode, it looks like the algorithm decides it is always preferable to sell to the grid, so the batteries never get charged unless the 5.5kWh sell cap is hit, in which case, the excess goes to the batteries. Other issues with this mode is that it pulls from the grid during periods of high usage (kettle) when rates are expensive rather than using the battery because the Target SoC for the battery hasn't been hit.

I'd really like to see a middle ground where the algorithm charges the battery enough to ensure there's enough to cover overnight consumption - or at least ensured enough charge to get to 2am when the battery can be charged cheaply. The simplest solution would be a setting that allowed me to stipulate 2 items:

- Restrict grid purchase to 2am-5am only.

- Set minimum SoC the algorithm should reach by sundown.

I'm aware I can use the VRM setting (Battery SoC Minimum), but this will switch to the grid if the battery drops below that SoC: I want to set a target SoC for the algorithm but continue to use the battery as long as possible.

Looking forward to further developments of DESS!

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petr-landsfeld commented · May 08 at 04:05 PM

Hi, I don't know who should i contact, but i would like to do Czech translation of vrm portal. There is lot of translations, but Czech is missing and in Czech republic is, i guess, big community of victron. Can you help me? Thanks a lot

Petr

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Dirk-Jan Faber (Victron Energy) ♦♦ petr-landsfeld commented · May 08 at 06:59 PM

I am the contact person for all of the translations within Victron and Czech translations for VRM is already being worked on. I expect that to be added within a few weeks.

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