I don't know about the Powerwalls, but I've heard a lot of nightmare stories about Tesla's solar panel operation. Residential and commercial fires, skipped permitting, sub-standard installation, non-existent service etc. Here's a recent article that just came out a few days ago: https://www.businessinsider.com/tesla-solar-panel-fires-walmart-amazon-safety-regulator-investigation-foia-2021-3