Who is more precise / accurate

[kevin1]

That’s a good question. The answer in my mind is “it depends”. It depends on two things:

1. Precision vs. accuracy - I’m assuming you mean accurate vs precise. Precision has to do with the number of decimal places in the measurement and how repeatable the same measurement is. Accuracy is about how close the measurement is to the “real value”.
2. What is the real value ? The inverter and the Sense CTs are measuring two slightly different things. The inverter is measuring the power coming out of some stage within the inverter, hopefully close to output. Sense is measuring the feed-in power to your panel. There are probably a couple of power losses that happen between those two points. The thing that I have found is that Sense solar is more accurate / consistent if you want to compare Sense net power vs. your utility company bill. My SolarEdge inverter was consistently 4% higher than my Sense solar, but the Sense Total Consumption - Sense Solar was consistently much closer to my net meter output. Here’s the analysis:

How Accurate is Sense vs. Utility Metering?

The next thing to do is to compare Sense against the other data source, our hourly feed from SolarCity, showing production from our 4.2kW solar system that uses a 2013 vintage SolarEdge inverter. All the data is going to be negative (energy consumption is positive, production is negative), so this might also give a little more insight into the negative tail of the net usage correlation scatter plots earlier. My first scatter plot of the hourly solar data, with coloring set to the month was lit…