I worked for solar install company as controller for a few years.  Payback was/is typically 12-15 years on a grid tied system and we are in a very sunny area, but depends a lot on what utility does, which varies widely (some buy back at retail, some at wholesale, etc).   Payback is likely getting longer now as labor and materials have gone up so much in the last couple years.  Battery backup is cool but absolutely not cost effective.  5kw battery backup is in the $18-20k range. It would only run critical loads for a period of time, so you have to REALLY want to not have any reliance on other energy, and have lots of disposable income to go that route.  I can go to Costco and buy a 7.5kw generator that runs on gas/propane/NG for around $800!  I am also definitely not ready for full EV vehicle.  Again, you have to be wealthy enough to have an 'extra' vehicle just for commuting more 'locally' (and don't get me started on the EV truck thing....if you use a truck for what a truck actually is for (pulling trailers/loads, its a joke unless you want to stop every 100 miles for 3 hrs).   I'm definitely not planning my trip across states or the country around where my stops for charging are going to be, and then sit there for a few hours.....  My opinion for average person is hybrid or plug-in/hybrid makes way more sense still.  Maybe in 10 years charging stations will be faster and more prevelant, and EV vehicle cost will drop...... or maybe the electric grid will be failing even worse since the infrastructure can't support all the charging needs (unless we stop demonize fossil fuels and go to more nuclear generation which makes a LOT of sense).  California's stated goals for electrification are waayyyyy out in left field, the grid can't manage today let alone the extra loads they want to put on the grid in the near future.  Just my random thoughts/observations.