[hbarka]

The Powerwall solar controller prioritizes the home before sending surplus to the grid. And in the home, the controller will send power direct to any running load first, then to the Powerwall battery. Any spillover then goes to the grid. It’s very dynamic. I would go with the algorithm to “capture the rain into my rain buckets the moment I can” because the rain could stop. Solar irradiance is unpredictable.

[mgiampapa]

If you have time based billing you can also input that into the system and it's even more effective. For example, if you tell it that electricity is cheap from 9am - 5pm (peak solar) and expensive from 5pm - 9pm (peak residential demand) it will take your trending consumption and decide when your solar production isn't keeping up with foretasted demand and let you charge from the grid to at the cheap rate to make up the shortfall and minimize cost. It even factors in things like grid charging speed and total site usage limits, which are great given my 100amp panel.

[OptionOfT]

The charging the battery from the grid on its own is interesting in spaces where the TOU between 4-7pm (or whatever yours is locally).

Here it is more than 3x, so if I can charge a battery and run off of that for those 3 hours, I am saving money.

And it's not that I can lose money, a charge in the battery doesn't become stale.

[gridspy]

Don't forget to account for the additional battery wear from extra charging and discharging. However your cost saving probably exceeds the wear cost.

[dzhiurgis]

> Solar irradiance is unpredictable

Except in my case it is! I wanna do most of my charge at noon when I'll have far more than I can export. Export first, then charge!