Question on Mains Power Being Used Even When We Have PV Power And Or Battery?

blobert

Hello

I have 40kw of PV panels attached to 4 x 8kw Deye Inverters(Sun-8K-SG04LP3-EU), 60kw of batteries and a 3 phase meter. I also have a Shelly 3 Phase Meter to monitor power usage and 3 Phase Zappi Charger. I just bought a Solar Assistant Raspberry Pi to try and further tweak my settings (based on advice here) but I have not set it up yet.

I have a weird issue, especially evident in the summer where we keep pulling small amounts of grid electricity during the day even when the battery is available and/or the PV panels are producing power. It tends to be using something from 5-12kw hour a day regardless of what's happening/how much I'm producing. It happens whether we're in the house or not, in the case of the screenshot it was on a day when we were on holidays but the usage still happens.

Is this unusual? Is there any way to stop it? It's relatively small usage but it adds up. In particular if I swap to Pinergy and want to only use electricity for 3 hours of the day to charge my battery etc, it's going to be annoying if it's pulling 10kwh+ every day at their 40c+ rate, it's likely to be a couple of hundred euro a year of unnecessary usage.

Any advice on what it is and if it's possible to stop would be much appreciated.

graememk

On the deye it tends to keep a slight import,

On your inverter settings, I can't remember exactly what it's called but its on the bottom right. Zero something, is it set to zero?

It will import if it's not exporting

serox_21

With my 5kw deye inverter I noticed similar usage before, small import 20-60W that would add up to 0.5-1Kwh or more a day.
Deye CT clamp is not really accurate especially at low grid usage. Combined with inverter default settings to always import 20W you will end up with some unwanted import.
I was importing 20-60W including when on battery or battery was charging from PV.
I set to import 0 from the grid and now is actually always exporting up to 60W.

Also when there are variations in instant power usage, inverter might take 1 or 2 sec to adjust the power provided by the battery, so you might end up importing/exporting from the grid.
Even now I get some small imports due to instant power variations(noticed it most with induction hub set on lower power). See 7-8PM highlighted in the second screenshot.

Set the import from grid setting to 0 and see how it behaves.

House Instant Power Usage is measured by a Shelly EM at the consumer unit,

Inverter House Load is measured by the inverter,

Battery Power is measured by inverter.

Electricity usage graph is measured using Shelly EM data at the Consumer Unit.