Maximising self-consumption with batteries

[jammyc]

Hi all,

I have probably got something misconfigured so apologies.

I am trying to model a grid-connected system with an existing load where the PV->Load takes priority, then any excess solar production goes to a battery which can then feed the load when the PV can no longer meet it; a grid import is available when neither battery not PV can provide. The load is relatively consistent through the year so the base (no-storage) scenario has a large amount of spillage in Summer. For economic reasons it is expected that the storage facility rating is likely to only be ca. 10-50% of the array rating for a few hours (of course determining those ratios is the task in hand!)

I thought that was the intended function of the "Self-consumption with storage" mode.

In the test model I have set up, I would have expected it to do nothing in winter months, then in the summer to jump from 2% DOD to 98% DOD as soon as the load is exceeded, and reversing afterward. However, for some reason when running the model, the battery discharges in the first few hours (which is presumably the starting DOD), then sits at the minimum DOD for the rest of the year.

Why isn't it charging? What am I doing wrong?!

Thanks in advance...

[André Mermoud]

First of all: what do you mean by DOD ?   DOD means "Depth Of Discharge", this is the contrary of  SOC, which is "State Of Charge":  DOD = 1 - SOC.

Therefore the minimum DOD  corresponds to a fully charged battery.

Now for your question, I don't know. Please send your whole project using "Files > Export files" to  Support@pvsyst.com.

 

 

[jammyc]

38 minutes ago, André Mermoud said:

First of all: what do you mean by DOD ?   DOD means "Depth Of Discharge", this is the contrary of  SOC, which is "State Of Charge":  DOD = 1 - SOC.

Therefore the minimum DOD  corresponds to a fully charged battery.

Sorry, my bad at the end of long day, yes I meant SOC.

[jammyc]

Ahah! I think the issue was that I had Grid Power Limitation active in Energy Management (from the simple non-storage option)... Deselecting this, but deselecting the "Allows solar injection into the grid" mode in Storage -> Self-consumption appears to make things work as expected.

[ashwazop]

The battery management which maximizes self-consumption transfers all power exceeding local demand into the battery. This way the battery is charged as early as possible in the day. Therefore the utilization of the battery is maximal.

[ashwazop]

 the battery is fully charged before noon and the height of the feed-in peak at noon remains unchanged. Only the beginning of the feed-in is delayed in comparison to the system without storage.  vidmate 2019 instasave downloader