As you can see, I am cranking solar output (and its still early!) and using 605 watts…
On the Sense Monitor page it shows that I am cranking solar, and DRAWING 600 watts from the mains.
So my question is;
Shouldn’t my mains be showing a negative number that is the sum of my solar on that phase minus the usage to indicate that I am pushing power back onto the grid?
It stand to reason to me that my mains should be at -2623 and -2670 respectively showing my solar pushing back out to the grid.
My solar power is tied supply side directly to my mains like so:
Good question. In short, no. What that is showing you is that you are currently using 348+260W in your house (for lights, always on, etc.). Most of that at this point is obviously coming from solar. You can effectively calculate how much you are returning to the grid by subtracting that value from 2971w+2966w. The reason it isn’t negative is the same reason it’s not negative on the main page. You are obviously still using energy and that’s one important variable we want to know.
One feature that has been requested in the past is a summary of solar production, solar return to grid, and utility pulled from the grid. What we have now is just solar production and total usage. We’ll need the additional information if Sense deploys rate calculators, etc. in future updates, to better estimate total energy ins and outs and cost/benefit.
OK, I understand, I jsut got it in my head that the Main CT’s we reporting that I am drawing that 608 watts from the grid, and the solar wasnt pushing back. So am I safe in thinking that the Sense unit itself is doing the math to show my usage and production, but I AM pushing back to the grid?
Yup, it’s doing the math, which is exactly what you want it to do to see total usage. If you want the delivered/received power, you need to look at data from your net meter.
You can check with your POCO to see if they offer a portal where you can log in and check your net meter stats. In my case, my POCO has an issue with their portal and billing platform for net metering customers, so they send me an email weekly with my daily stats that looks as follows:
I use a Rainforest Eagle to access instantaneous NEMs power usage and 5 min sampling of energy usage in my house. It reads the net meter via Zigbee and sends results to my computer via Ethernet/web interface. https://rainforestautomation.com/rfa-z114-eagle-200/
Date Delivered (DE) Received (RE) Net