The interesting thing was the incredible rate of decay in the Powerwall, financially it makes it completely unviable.
I need a battery that can be recharged from the off-peak mains supply. If I charge the battery from the solar system I lose 60cents/KwH in rebate only to use it off-peak at 22cents Kw/H. Much better to charge at 22c and use it during t h e 27c peak hours and minimising to use of solar.
With a 5Kw system that only averages10.1Kw daily with a max. of 21.8Kw and a min. Of 0.32Kw and an average daily use of 15.4Kw peaking at 52.9Kw in summer you can see how big a battery is needed.
Some of the posters on here assume that the output of a solar systemis nameplate times hours of sunshine when in fact you are lucky to get 17%.
Point in fact, Windorah Solar Farm has 5 x 14 metre dia. solar collectors costing $4,500,000 that produced 100,000Kw in the course of one year at one of the sunniest locations in Australia serving a population of 100 people. It uses diesel generator backup and for 2 months of the year it is useless.
Opened in 2007 it now has 4 collectors unservicable.