Force DESS to self-consume for some period of time

Q&A and troubleshooting DESS
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Hi there,

We often run into the issue where DESS plans to reach 100% SOC mid-day, but consumption ends up being lower than forecasted or PV production ends up being higher than forecasted.

In those situations, the system feeds solar into the grid for essentially no compensation (given the battery is full). Given the size of our system, this can be resolved by “self consuming” from battery earlier in the night, before DESS’s own plan to self consume (creating an SOC buffer).

Is there a way to force DESS to self consume for some period of time, via an automation? Basically, ignoring the DESS plan for X hours, but also allowing DESS to update the plan as the SOC drops. The logic being… “if SOC is projected to reach 95%+ in the next 24 hours, then self consume now for 3 hours” (or something).

I can use node-red to switch to “Inverter Only” mode, but I’d like to find a solution which allows us to keep the system “on grid”. I can turn off DESS temporarily, but then the metrics get thrown off slightly and the DESS plan takes a while to update to the new SOC (resulting in a brief charging period from grid as the plan updates).

Alternatively, it may be nice to have SOC buffers at the top and bottom end of the battery, in DESS settings :slight_smile:

Thanks,

Aakash

2

I do exactly that with a Node-RED flow that monitors the strategy of the currently active schedule and override (set) it to 1 (self consumption) when DESS attempts to (re) set it to another strategy (every so many minutes).

The basic override flow is reasonably straightforward, things get a little more complicated when you want to automate switching this override function on and off. Be prepared to do a deep dive into the inner workings and timing of DESS and add additional checks to your flow to prevent unintended behaviour. For instance:the first few minutes after the whole hour, DESS uses schedule 4 instead of the expected schecule 0 (15 minutes scheduling).

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Which item do you use for controlling and setting to 1 in node red?? I want to do the same, but not 100% clear which setting to query and update.

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