In addition to installing the solar panels (16.4 kW) and two Powerwall2 units, that is just the beginning of the project. It is not just about producing electricity, it is also about minimizing kWh used so that more kWh are available for the car.
So far I have installed:
Two Ecobee3 smart thermostat units, one downstairs, one upstairs. Our house is 3,400 sq ft, two levels, in Florida with two AC units to control. This was a big savings right away. Just programming the upstairs AC to turn off while the kids are at school is reducing demand by 10+ kWh per day Monday thru Friday. I programmed it to turn off the AC at 6 am, the teenagers leave for school at 7 am. Then it is set to cool down the upstairs at 2:30 pm right before they get home.
Aquanta smart wifi control for the electric water heater.
So after much research, smart tech is much less common for water heaters. Aquanta seems to be the best one I could find. It hooks up to almost any type of water heater, then with Wifi and temp sensors, it takes over management of the water heater. You can then use the app on your phone to control the schedule, or let it manage everything. Stop heating water at night or during the day. Just heat it up when you are likely to take a shower or whatever. I just got this installed today, so I am not sure how much it will save. But it is obvious my electric hot water heater is a big consumer of electricity in the house. I am expecting over 5 kWh per day savings from this item.
I am trying to avoid Alexa and Google technology. Just trying to buy smart items that work with Apple Homekit or Samsung SmartThings apps. So far it is all working well together.
I am looking for more smart tech to add. But from everything I have read, the air conditioning and the water heater are the two major items for efficiency gains.