This is something I know very well (day job)
It all depends on your utility rates for payback.
So many different tiers, so many different rates across the nation. If anyone is truly interested me om me and I'll give you the most detailed analysis for free.
On to the equipment because that's what we care about here. My opinion is that the grid is very hard to replace. Unless you have special circumstances, you want to be grid tied.
With that said, battery backup / playing with time of use rates can be profitable. If you have the interest/skill/time to build a non off the shelf system you can do it reasonably (still not cheap)
For the average homeowner the best quality and most cost effective system would be SolarEdge+lg chem battery.
There are warranty/reliability/code reasons behind that choice.
A $5kwdc solar + 10kwh backup system costs $25k. You get a critical load panel and about a day or two of backup.
If you want an accurate financial analysis there is much much more. The largest mistake I see in proposals is inaccurate utility rates and utility rate increases.
It's a big decision that I'm confident will pay for itself but the production part is easy to understand, the financial math is a little more difficult.
Sent from my Pixel using
The Garage Journal mobile app