Consumption and Generation from two different sources?

scoob8000 · January 23, 2025, 9:00pm

Pretty new to solar and PVOutput. I have Iotawatt devices with CT clamps. One on my main panel, and one in the subpanel where my solar is.

I’m uploading solar generation and voltage from one. But I would like to upload consumption data from the other unit. Will that corrupt any of my data if I’m uploading from two seperate sources?

Part two of that question, the CT clamps recording my consumption go negative when I’m generating more than I consume. Not sure if that’ll hurt the data either.

Cheers!

scoob8000 · January 24, 2025, 5:27pm

Update: I have my consumption uploading by itself and it’s working fine. But I’m not sure if pvoutput is happy with the negative consumption values.

About 9:30am when the red line disappears is where my consumption went negative as I’m feeding back to the grid at that point.

scoob8000 · January 25, 2025, 1:26pm

Update 2:

So seems to be working, and there are others whos graphs look the same.

But the only downside I see, is net energy is incorrect since it think’s we’re exporting 100% of what we generate while the CT clamps on the mains is negative. Is there a setting I’m missing to work around that?

scoob8000 · January 28, 2025, 4:39pm

Update 3:

I made a homebrew solution. Solar generation, and consumption are recorded to influxdb. Since my consumption goes negative when I’m feeding to the grid it throws off the net energy value.

My work around is a script that queries influxdb every 5 minutes for both values, and subracts generation from consumption, and uses curl to send the result to pvoutput… The result is the power the house is actually consuming.

john942s · January 31, 2025, 5:49pm

It looks as though your ‘consumption’ CT is actually measuring import/export to the grid. Can you move it so it’s measuring the total power the house is actually consuming, including the solar generation? Then PVOutput graphs can show you the import/export as Net Power and Net Energy.

scoob8000 · January 31, 2025, 7:40pm

I think that’s what I accomplished with my solution. The problem was because I’m backfeeding from a subpanel, I have no way to measure only what the house is using. My solution was to take generation from the CT’s on the solar, and the total from the CT’s on the main breaker, anb subtracted generation. Now the red line is just what the house is actually using.

This is after my homebrew solution…