If you can wait a little, like a month or so, you can check against your first full utility bill.
OK, this one requires some patience and it may not totally work out for you for reasons I’ll touch on at the end. Take a look at your first full utility bill after you have installed Sense. That could mean a worst case wait of almost two months. @samwooly1 has posted a few comparisons on the forum showing his good results. But there’s a extra step for us solar users.
Here’s my most recent NEMS (net metering) billing summary. I’ve been shaving energy usage since January, partially thanks to greater solar production, and netted 1420kWh of usage in the period that started on 3/23 ended on 4/21.
That’s going to make it tricky fo me to do an exact comparison with Sense, since the built-in intervals (Month or Bill) don’t exactly match, but I’ll do the best I can. First, I’m going to set the Billing Cycle Start in Settings to the 21st, so that I’m at least matching up on one end of my most recent billing cycle (4/21).
Then I’ll go to the Trends > Usage > Bill screen. If I touch on Usage, I can see my Usage for that Sense billing period, which doesn’t quite line up with my own.
Then I touch on Solar to get the solar production for the billing period.
That’s 2000.3kWh - 501.2.kWh = 1499.1kWh. But that’s a little too big ! Sense included two extra days so I’m going to need to subtract them off. I can put my finger on each of those days and the “mouse-over” will give me the Usage and Solar for each day, like below.
So I can subtract off 3/21-3/22 as (55.0-22.3) + (59.7-23.1) = 69.3kW. 1499.1kWw - 69.3kWh = 1429.8kWh vs. 1420kWh billed by my utility.
Once again, my total error/difference with Sense is within 1%, though this time Sense gives a slightly bigger number, in comparison with my earlier my spot check.