My sense monitor was off-line because of powerwall installation. Around the same time I had to replace the well pump (Yes, it was an expensive month!)
After weeks offline, I finally reinstalled my sense monitor and I can see a weird appliance coming on every 30 seconds for 1 second at about 1kw, days and night.
After investigating, it turns out the check valve on my pump is broken and the pump runs constantly to keep up the pressure. Very happy to have found it, the wear on the pump would have killed it much sooner than expected, and the early fix is only a $20 part!