Thanks for the note and the vid! I need to get a calculator, but looks like you generate an average of about 0.5 kwh per hour in use, which is presumably the time since installed - about 1.5 years in your case , with a 2kwh system Is scaling linear? i.e. roofspace notwithstanding would a system twice the size of yours generate twice the power on average? that would generate an average (over time) of 1 kwh per hour so about 12 kwh per day. That seems pretty substantial compared to the usage figures being given by people on the thread. No tinfoil here, or desire to go full hippy. Just fed up of permanently rising costs from energy companies who seem to do very little about transitioning to a more sustainable model (cost or environmental) and the Tesla announcement seemed like a potential alternative. Basically I want to see how close to self sufficient you can get by doing as as Harlequin has done, but rather than sell back excess midday supply, timeshift it by storing and use that during peak evening demand before buying from the grid if/when the surplus is drained. I live in a 4 bedroom detached bungalow so have a fair bit of surface area on my roof.