Signed up yesterday to have a somewhat large 24.3kW system with 4 Powerwalls installed at my home which looks like this with 60 panels overall. The front of the house faces Northwest and back of the house is Southeast.
This system is in southern NJ and AC Electric is the Electric service provider. Here are some questions I was hoping to get some input on:
This system is in southern NJ and AC Electric is the Electric service provider. Here are some questions I was hoping to get some input on:
- Inverter Ratio: The team told me the Powerwalls would be Powerwall 3. I've read and understand they have a built in Inverter that has 20kW DC to 11.5kW AC or a DC to AC Ratio of about 1.74 which seems high from what I've read. Is this right?
- Solar Clipping?: If the DC Solar max is 20kW and my system is 23.4kW (60 panels at 405w each), wouldn't I see clipping of the additional 3.4kW if the system can get to max at any point in the day? I did read that the max rating of the panels is in a lab and not normally the true output, with 400w panels generally generating more like 305-310w in the real world. Is this true? If so, I guess this is fine since max solar DC output would be 18.6kW and PW2 can handle 20kW.
- MPPT/String Config: It looks like the powerwall 3 spec shows 6 x MPPTs which means they can zone the system into 6 separate sections for max efficiency, even with the configuration being split only across 2 sides of the roof. I'd assume that I should request this since there are times in the early morning and late afternoon where there is shade on various corners of the roof. With the design they sent above, I assume they will do 2 strings by default, but should I ask for 3 sections on each side so 6 in total?
- Placement: In the google satalite photo, the electrical panel is actually on the side of the house you can see, opposite from the driveway, towards the front of the house. The main panel sits in the basement around the same place. Based on the below system design, would they have to put the 4x Powerwall 3 on that side of the house? When ordering I chose "Let Tesla Decide" because I didn't want to pay $1800 to have them in the garage, even though I'd prefer them to be there. Is this a big deal?
- Is anyone familiar with AC Electric in NJ and any "Gotchas" I should look out for. I've heard things like the Electric company can set a max of 120% of electric generation (which, believe it or not, 24.3kW is 97% of my 12 month avg generation) but also things like not allowing the PWs to be charged from grid. I've heard some have exceptions to this where they allow it only through storm based functionality like Tesla's Storm watch.