Is it possible to set a minimum SOC when using green DESS?
I want to keep it at a higher SOC than green DESS wants to get it to, so i have enough energy for when the grid fails.
DESS uses the normally set minimum SOC. You do not need a separate setting for this.
That is a bit confusing for me.
The minimum SOC was for when you want to stop pulling energy out of the battery and start using the grid.
So if that is now being used for DESS, that would result in using grid after it is done exporting energy in the evening, for the rest of the night?
Or did the function of that setting change with DESS on?
I don’t understand what you actually want. The battery is never discharged further than the minimum SOC. Regardless of whether DESS is active or not. (As long as grid is available)
Yes, that is what i thought, and there is exactly the problem.
My green DESS wants to discharge the battery in the evening to the grid, what makes that the battery percentage at midnight is around 50%.
So, what will happen then? It starts using all power from the grid?
I want green DESS only sell excess energy to the grid, not all the way down to the minimum SOC level, that i have set at 50%.
That is why i asked for a separate SOC setting for green DESS. That one i would set higher.
The DESS will not discharge to your minimum SOC at midnight. The DESS will discharge enough energy to maintain the minimum SOC at the end of the time interval—that is, until the end of the time when it has prizes—or never fall below this minimum SOC.
Why does my forecast graph tells me it will reach 50% SOC at midnight then?
For today, it wanted to discharge in the morning for some hours, and then in the evening from 5 till 12, until it would reach 50%.
Maybe the SOC forecast is incorrect and it will stop earlier, but it looks really strange to me.
I guess i have to try it out.
I’ll put the minimum SOC at a higher number and see what will happen.
I now have set minimum SOC to 80%, green DESS has changed to discharge this evening from 5 till 10pm, when it will reach 80% SOC.
Maybe it will stop before that, i’ll try it out, but forecast looks not promising.
So I’ve been using the DESS for 1.5 years now and work with the Min Soc all winter and for me it reacts exactly as described.
So it arrived at 80.1% and said ESS#1 in battery.
Stopped using the battery and started using grid power.
(It did change the discharge a lot, less discharge in the evening, but still too much to have not enough energy to make it till the morning.)
Exactly what i didn’t want to happen.
If it didn’t discharge yesterday evening, it would have been fine.
But this is the reason i was looking for a separate SOC input for green DESS, that way, if it reaches the low DESS SOC, if that value is set a bit higher then the low battery SOC, it doesn’t start using electricity from the grid at a time when the price is high.
If configured correctly, it won’t do this. Please check your settings.
how long and reliably does your consumption forecast run
I try to let it run for some days now, but it keeps doing things i don’t want it to do.
Do i just have to let it do stupid things first for a while before it starts to run normally?
I just do not understand why it wants to discharge the battery to the minimum SOC and then just simply uses grid power to fix the mistake it makes. Even if the DESS is new, it should understand that if it uses the energy until it’s at the lowest SOC, and the forecast doesn’t show enough solar energy for that time to maintain the loads, that it needs grid power at the highest price.
And even if the system runs for a while, what if suddenly you are using more energy in the night than other days, does that mean that it will use grid power too if lowest SOC is reached?
There should just be a minimum SOC for DESS, and one for the lowest you want your battery to discharge before it starts using the grid.
Once the DESS has been running for some time, the forecasts improve. The DESS then always uses electricity at the most expensive times and draws it directly from the grid at the cheapest times. If more electricity is consumed than expected, the DESS looks for the next opportunity to cover this additional demand as cheaply as possible and still have energy in the battery at the most expensive times. In my case, it does this almost perfectly, even with two households, two wall boxes, and a heat pump. Unforeseen consumption almost always occurs somewhere. Nevertheless, the DESS usually reacts quickly. It is important to set the parameters accurately. Not only the maximum charging and discharging rates, but also battery costs and pricing formulas.
Okay, i will let it run for some time, and see how it will behave.
But still, I’m convinced it need a separate SOC for green DESS, so if it runs below that, it doesn’t just stop using the battery and getting power from the grid at the highest rates.
Do you have also no problems when the system discharges to the grid, and then stops it before the hour is over, because it reaches required SOC, it starts using grid power over battery power for the rest of that hour?
I do not charge any electricity into the public grid at all
Ahh, that is why you don’t have those problems.
No…I just buy more electricity accordingly. The system is the same.
This morning at 7 it started discharging to the grid again, until it reached 80.1% SOC. Then it started using grid power again, now at 8.20 there is enough solar energy available, but it still uses grid power for the loads while it is charging the battery.
Really not a situation i want.