So.....7 months since I started all of this and nearly 2 months since I *thought* it was all finished.....it's finished.
6k of solar in 16 panels split into east / west arrays, 7.2k of batteries running off an AC inverter and a Zappi to charge the Tesla
We haven't (yet) fitted the iBoost to heat the water because our HW tank is old and fragile so fitting an immersion may break it.
Total cost was £11,250 for solar, batteries, all the fitting and far more wiring than I expected plus £1,174 for the Zappi. (Since I started this and fixed prices I believe they have gone up by at least 20%).
I'm currently on Intelligent Octopus paying 10p / kw between 23:30 and 5:30 and *a lot* during other hours - I missed the 7.5p deal because Octopus took so long to get the Zappi working (4 engineer visits to do what I said they needed to in the first place). But I'm actually selling surplus for 15p so it isn't too bad. Now the days are short, I set the batteries to charge overnight and pretty much never hit the grid in the day - everything comes from solar and battery.
Here's my Octopus power usage for October
That's 81KwH exported and 177 imported. Of that 177, >90 was to charge the car.
Here's what a day looks like (Octopus glitch export is from a day earlier than the import - it rained pretty much all day on the export day which is why following import is so high.)
In the summer I won't be hitting the grid at all.
If you can afford it and have the space, get it. If you don't have the space or money for a full install then look at batteries. I reckon for £4-5k you may be able to shift all your power to night time which will cut electricity bills by about 65%. That's a reasonably simple payback calculation.
Oh and don't get me started on how awful the app for a Solis inverter is. next step is Home Assistant.
@wyx087 - I'll have questions