Just wanted to offer another view on Sense vs other power datasources. I have recently been working with Sense data under Home Assistant, since Home Assistant offers a great way to pull together time series power and energy data for my entire house, even in areas where Sense already does a good job. It turns out Home Assistant has an integration to pull in data from my smart meter, through my previously used Rainforest Automation Eagle bridge. Since I have a PG&E net meter, I was never able to look at the big picture including solar, like I am with Sense, but with Home Assistant, I have a chance to do real-time comparisons between Sense and my meter. Here’s a view with Sense Total Usage in orange, Sense Solar in blue and my net meter in green. Not surprising, at night, the orange (Sense) overlays the green from my meter. The big plateau on the right is the charging of our Model S.
Here’s why accurate samplings of my net meter are pretty useless - There’s no way to see Total Usage. And even though the brilliant guys at Rainforest compute an “Always On” value, it is useless because it is not based on Total Usage.
One final note - here’s why it CAN be very hard to compare power usage to determine accuracy - sampling intervals. Here’s a snippet of data for my first chart. As you can see, the Total Usage and Solar are sampled on one timebase and interval. My Eagle net reading is sampled on another timebase and interval. But how does one line them up to compare ? The real answer is that we really need to do numerical comparison using energy using fixed time points, unless I can exactly line up the sampling (and rule out any latency in the measurements).