New Construction, Add Generac PWRcell 9kw?

[saxon11]

New house construction going on, and would like to add solar for the following:

1. backup energy for essentials (such as well, heater fan, fridge identified in separate subpanel) for when grid goes down
2. send electricity back to grid if overproduces
3. possible to add in future with another inverter and batteries

This generac system 9kw seems fairly legit and has batteries. What do others think of this? Economical, smart to hedge again future electricity price hikes? My panels will be ground mounted outside in backyard, panel and PWRcell would both be in heated garage. thank you

 

[BentleyJ]

One of the unique features of the Generac PWRcell system is the load control modules that can disable high demand, non essential appliances for example an electric range when on inverter power. The advantage to this architecture is that you probably do not need a separate critical loads subpanel.
You can potentially back-up the entire main panel and set the load control priorities in the software. A major advantage here is that you can change which appliances are turned off and have usage of everything in the house, just not all at the same time. With a critical loads subpanel the only back-up you get is whats connected already. If you need one of the other appliances you are stuck running extension cords or moving breakers or something.

 

[saxon11]

For this Generac 18kW system, would 30 panels at 430W each feel about right size? I'm in MN.

 

[BentleyJ]

For this Generac 18kW system, would 30 panels at 430W each feel about right size? I'm in MN.

There is just no simple way to answer your question. First it is necessary to make a spreadsheet of all the appliances you mentioned and Estimate the electrical demand, both peak demand when everything that you expect to use simultaneously is on and average daily seasonal demand.
Once you have a reasonably accurate estimate of electrical usage then you can size the system.
1) Use an online calculator to determine the ACTUAL average daily output of your proposed solar array using azimuth, tilt and zip code or Lat-Lon. Since its ground mounted you have the advantage of being able to construct the mount at the ideal angles.
2) Size your inverter and batteries according to peak demand and which appliances can be put on load controllers.
3) Size your batteries based on budget and how many days of back-up you need for diminished sunlight days.