Deciding on a Powerwall Setup - Would Second PW Skip Sub Panel?

[Foxbat100]

Good afternoon all!

I was just hoping to solicit opinions on 1 vs 2 Powerwalls - I have an order for one but having trouble finding out if two would skip a subpanel since Tesla thinks I'd have to redesign to get a quote on that!

I have the following:
-6.6kW solar array with microinverters that come together in an Enphase combiner.
-NEMA 16-50
-electric water heater
-electric stove/range
-electric dryer

I don't have an air conditioner or any other major draws, so I can't imagine two PWs couldn't handle all of the above.

Would I save money if I just got two and skipped the subpanel? The website has a "Other electric vehicle are compatible for backup with a minimum of 3 Powerwalls" but I'm assuming there's no reason to not connect the 16-50 plug into the powerwall?

My basic goal is to be able to use the solar panels in case the grid is down and to avoid peak usage.

 

[BrettS]

You’ll need some additional panels no matter what. If you go with a partial backup then you’ll need a new panel for the backed up loads. Even with a whole house backup you’ll still need a panel behind the gateway with all of your loads. Depending on how you are set up now, then it’s possible that your existing main panel could be used for this. However there are some cases (such as when the meter and the main panel are in one unit) where the existing main panel wouldn’t be able to be moved to be behind the gateway.

 

[jboy210]

We have whole house backup with 2 PWs. Our loads include a Tesla WC (240/50A), electric dryer, and A/C. So you should be OK with 2 PWs. They analyze your power bill to see if this is true.

The issue with 1 PW is the 5 Amp per powerwall limit. Turn on oven and dryer and you are beyond this. To get around this they install the subpanel containing only the essential items that are backed up.

 

[wjgjr]

We started out planning for one PW and went to two PWs. To answer the cost question, yes, you could save money installing two PWs if you do not need a sub-panel. The installation portion of our PW costs dropped by $500 total for two because we went to a whole-home setup. (Of course, the overall cost for two is still higher than for one.)

Certainly sounds like you could do whole-home with two PWs, with the understanding that when off-grid, you may not want to be charging the car, and certainly not charging while doing laundry and cooking dinner.

 

[Foxbat100]

Thanks a lot all of you for your time responding! Glad to know installation cost going down is a possibility.

Definitely agree that I don't want to be charging the car and doing laundry! Mostly the goal is to be able to charge the car straight from the solar panels in the daytime when the grid is down, and from the looks of it, the EV port will end up on the non-backed up panel and therefore locked out when the grid is down, so a lot to think about!