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solar + powerwalls + model S

solar + powerwalls + model S

Hi -- im sure this is posted in one form or another somewhere but i couldnt find my exact answer so here goes.

I am looking to deep dive into the tesla ecosystem.

Goal:
I would like to purchase enough solar and enough powerwalls (5 i think) to run my entire house and charge model S overnight.

My question is:
1. is this currently possible? powewall site says off-grid is coming soon?
2. can I charge the powerwalls via solar during the day and have them discharge power for everyday living (TV+AC+washer / dryer + lights+ PC+ oven + etc potentially running at the same time every now and then) . I figured since the powerwall2 can discharge 5kw continuous that if i needed to run everything all at once then i potentially could see using upto 25 kw (not accounting for car charging -- not sure how to calculate that in).
3. Anybody have a good idea of how large solar system i would need (guessing 12-15kw system).
4. Ideally i guess i would want it totally off-grid, but maybe just charge the car from grid and for the house use sun+powerwall daily.

Thanks for any help/useful sites/ etc

Travis

nutts1 | 05. Januar 2018

I just placed my order for your exact scenario. My annual consumption is 18,000kw. My system was designed with 13.5kw of panels and 3 power walls. It should cover 101% of my usage.

nutts1 | 05. Januar 2018

PS, I am in NJ and have an ideal southerly exposed roof.

Tesla-David | 06. Januar 2018

Before you jump into a massive solar/PW2 installation, analyze your annual energy demand. I live in Edmonds, WA and downsized in 2012 to 1987 built 2000 sqft home. We conducted blower door test to evaluate our energy demand, and then conducted extensive weatherization repairs to improve the energy efficiency. We reduced our annual energy demand from 12,000 kWh down to 4,700 kWh through these repairs, which also included LED lighting etc. We went with a 13.2 kWh solar system with microinverters because we had shading issues and have been net positive over past five years, producing 256 percent of our energy needs in all electric home, which included charging our MS, and will soon also be charging our M3. I am waiting to get two PW2 installations, which will give us all the backup energy we need to power our home during most months of the year. I am retired so I am not driving as much as before, but am using around 2,000 - 3,000 kWh/year for our MS charging.

You say you would want to be totally off grid, but that would depend on how much energy production you would get from your panels especially during November, December, and January, which are the months where I do not get enough solar production to cover our energy demand in Northwest Washington State. If you live in Arizona, Hawaii, Florida, etc. I would expect you might get enough to make enough energy every month.

@nutts1, if your annual consumption is that high you definitely should be looking into weatherizing your home, as that is quite high relative to my example for our home. It is money well spent, and would help you meet your goals.

Tesla-David | 06. Januar 2018

As a follow up to my summary above, our home was certified as being a Net Zero Energy Building(NZEB) by the International Living Future Institute in 2016. I have linked to a summary of that certification for anyone interested.
https://living-future.org/lbc/case-studies/sustainable-dreams/

taw34 | 08. Januar 2018

thanks guys for your info --
@Tesla-David -- ideally this would be a new house build, but i agree everything weatherization related would and should be done first!