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kfl avatar image
kfl asked

Maximize Solar Use when Grid is Available

I am no expert but ...... I have a solar array and can generate in excess of 2kw of power from early in the morning, but the system seems to like GRID power more than SOLAR.

Below is a screenshot of the system when the grid is available . (note the high use of grid power and ESS enabled )

Obviously I would like to use more Solar Power so i turn off the mains and a second later get .......

Surely the system should prioritize solar use, otherwise what's the point in having solar - you might as well have just an inverter.

I would assume that VICTRON - have an easy way to enable the prioritization of SOLAR power and that their Inverter control systems are intelligent enough to know that it does not really matter if the batteries discharge in the early hours of the morning because the sun will be up in a couple of hours and there will be plenty of power to charge them back up. I would not even be surprised if the system took into consideration the forecasted weather conditions and historic usage in deciding on what actions to take.

What am am surprised about is that in most of the Question replies I see Victron staff explaining how to write code and python scripts to try and implement this ........ surely this should be part of their solution?

If anyone has some not technical easy solution - I would greatly appreciate the help.

Thanks.

solar
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laurentscholtz avatar image laurentscholtz commented ·
I have exactly the same question. i would prefer the soalr to feed the house first, and then use the remainder to recharge the battery. I am using too much Grid initially, and then not using surplus solar later.
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nickdb avatar image nickdb ♦♦ laurentscholtz commented ·
The issue from the OP is that ESS was hitting its configured or active limit hence the ESS#1 and #2 states shown.

The system always prioritises solar for loads, if you are using grid that is because you have hit limits or run the battery down, in that case loads will always be covered from grid and solar dedicated to charging until you are above minimums.

That is how ESS works, so you need to tune your system correctly or appropriately size the battery, the symptoms described sound like a pack that is too small.

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laurentscholtz avatar image laurentscholtz nickdb ♦♦ commented ·

Great. Thanks for the reply. So you are saying there is a setting where you can set this minimum batttery % to recharge to before sending Solar to the house for usage. What do you call this setting?

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

https://www.victronenergy.com/live/ess:design-installation-manual

Chapter 6.5 - You have ESS #1 and #2

#1 is preventing the discharge of the battery
#2 is forcing the battery change from PV

What batteries do you have?

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kfl avatar image kfl commented ·


KFL answered · 1 sec ago


Thanks for the quick response - I'll go through your answer

#1 is preventing the discharge of the battery
- So the Battery charges using Solar and stays fully charged or up to 95% SOC (This is what I want) so when I loose power I have full batteries.
#2 is forcing the battery charge from PV
- Yes that's okay as have plenty of solar so why use the GRID

What batteries do you have?
- Lead acid batteries 8 x 12v 250 amp in a 48V bank.

OKAY BUT THE ISSUE IS

When I turn off the GRID the System then uses 2.7KW of SOLAR (maximum Solar).
Why does the system not use Maximum solar even if the grid is available. As you have pointed out Both ESS 1 & 2 make the system favour solar. The setup is weak in that it is not fully using solar!

I hope this clarifies.

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ kfl commented ·

Do you get #1 and #2 as soon as you switch on the grid?

Can you make pictures of the ESS settings (GX device and the ESS assistant of the Multi)

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kfl avatar image kfl Matthias Lange - DE ♦ commented ·

No seems to only come on at higher SOC%

You can see that during lockdown (Last 14 Days ) we have had more GRID availability. Due to the preference of Grid Power by the victron unit I have using less and less solar.

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screenshot-2020-04-12-at-111550.png (30.5 KiB)
kfl avatar image kfl Matthias Lange - DE ♦ commented ·

Attached my config file
64cfd965d862_inst_ttyO1_Interfaces_Mk2_Tunnel.rvsc.zip


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screenshot-2020-04-12-at-112421.png (29.5 KiB)
screenshot-2020-04-12-at-112435.png (25.7 KiB)
64cfd965d862-inst-ttyo1-interfaces-mk2-tunnelrvsc.zip (2.6 KiB)
kfl avatar image kfl Matthias Lange - DE ♦ commented ·

Hello Matthias Lange,

You can see from the following the Victron is definitely not using solar - a mostly cloudless day and for some reason we stop using solar at 14:00, just because the grid is available. How do I set it to Prioritise Solar not just for the battery charging but for loads as well? I just want the grid to be used when there is not enough solar and battery is below SOC 95%. I can use scheduled charging to Grid charge batteries out side solar hours.

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screenshot-2020-04-13-at-170153.png (25.2 KiB)
kimmo-paukku avatar image
kimmo-paukku answered ·

Hi

What is your CCGX grid set point ? Is it that +2000W?

Maybe Im wrong, but...…. A while ago, I noticed, that if I have grid set point something else than 0W, it will reduce PV production while absorption, see attached pictures. It seems that, grid is priority instead of PV. My common sense say, that this should be other way around. If you have panels connected, panels should be priority....

Multiplus 48/5000, CCGX, ESS, 2xcharge controller, 6xpylontech, SOC 20%

Sorry my bad English.


Few seconds later, I adjusted grid set point to 300W... and PV drop to 218W.




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kfl avatar image kfl commented ·

My grid point is set to 50W - I am told that is should be slightly positive to avoid feedback i to the grid.
Your english is great! - and like me you agree that the PV should have higher priority if there is PV available. - It would appear that victron to not understand this.

I can generate 8KW of power at the moment I only need 4KW - I'm getting 90% pf power from the grid and paying for it when I could be 100% on solar if the victron unit gave PV Priority.

Off i go again to turn the grid OFF.
According to Victron

Chapter 6.5 - You have ESS #1 and #2

#1 is preventing the discharge of the battery
#2 is forcing the battery change from PV

SO WHY AM I USING GRID - Mattias?
Why does the unit favour GRID over Solar?

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kfl avatar image kfl commented ·

Will Try Setting to 0W



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wannibi avatar image
wannibi answered ·

I am experiencing the same issue. Battery was discharged to setpoint overnight and the next morning, with a favourable forecast, loads is powered by the grid whilst batteries is charged with solar.

There is a need to prioritise solar direct consumption and postponing charging to later based on the forecast.


At the moment I have to manually tweak the system every day based on the forecast by lowering the discharge limit.


None of the ESS settings currently incorporate or make use of the forecast, with it merely being a nice to know.

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wannibi avatar image
wannibi answered ·

Dynamic ESS should be expanded to include dynamically changing values based on conditions or forecasts. This is currently only doable by side loading NodeRed. Given the forecast models already well established, this should not be difficult to implement.

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