Powerwall 2 in cold climate

[bradbissell]

I have a question for those of you with Powerwalls in cold areas of the world. I am interested in adding at least one, possibly 2, Powerwall 2s to my 5.4kW PV system. I live north of Boston MA and it can get pretty cold at times in the winter with limited sunlight. I am wondering how the Powerwall 2 copes with extended cold weather and the real world usable capacity during those times.

I want to add a powerwall, rather than a generator, to power the critical circuits during rare 24-72hour power outages (forced hot water radiator heat, pellet stove, sump pump, refrigerator, chest freezer, microwave, and limited led lighting). During those times I believe the total power used in the house would be ~7-10kWh per day.

I have owned a LEAF and the battery was able to deal with the cold weather since I charged at night when the temperatures were the lowest, but usable capacity did drop considerably. If the Powerwall 2 is installed outside on the north side of the house (best location due to electric panel). Will the Powerwall 2 be able to maintain a reasonable capacity in the winter?

Thanks!

 

[abasile]

Based on our experience with EVs in cold weather, I'm guessing that the usable capacity of the Powerwalls may drop by something on the order of 20% when temperatures are well below freezing. They should be capable of warming themselves, but that takes energy. Honestly, I really don't know exactly what to expect, but I'm not inclined to believe that the cold-related capacity loss will be too terrible.

Our situation has some similarities with yours, as we're in a mountain area that, from time to time, receives feet of snow and stays below freezing for days. It's during such times that power outages seem to be most likely. If our solar panels are covered in snow and ice, we obviously won't get much production. Tesla's current plan is to install two Powerwalls on the north side of our house, in a sheltered area near our electric meter. (The permit application was submitted but they haven't given us an installation date yet.)

We had originally planned to install just one Powerwall and decided for sure to go with two Powerwalls when it became clear that Tesla requires at least two Powerwalls to back up circuits on 40 - 60 amp breakers. It also seems that having two Powerwalls will significantly increase our odds of making it through winter outages with enough stored energy. Besides, we'll have more to play with in the day-to-day "time-of-use load shifting" that we intend to do.