I live in the coastal zone so there's a lot of overcast days. If I lived a few miles inland there's be many more hours a yar of direct sun but my consumption of electricity for cooling would also be a lot higher. We work from home so my energy consumption is higher than probably any of my neighbors because we're here most of the time and we're running office equipment.
The electric portion of my SDG&E bill runs about $1200/year, of which almost 50% is fixed - meaning it costs that much whether I ever flip a switch on or not. We're talking connectivity costs including various fees and bonds and the like. That means my actual electricity *consumption* is about $600/yr. (actually, I'm rounding up a bit)
If I were to assume a 3% annual increase on my electric bill, the total payments over 20 years - which it the effective lifespan of the alternative of adding a solar system with batteries - amounts to a little over $16,000. That's assuming I could generate and store enough power from the system to meet most or all of my needs on most days and only occasionally dip into using grid power when it rains for a week straight or we get a heat wave that causes me to use more fans in my home. Also assuming my battery array would last that long - which I highly doubt.
A solar install for that much electrical usage - given my location near the coast - would cost at least $15,000 at this point (probably more due to my extra usage), regardless of who pays for it. Meaning whether the gov't intervenes in the market for me and subsidizes my costs. You can buy kits for less, but they still need expert installation.
That $15,000 install cost is if I purchase the system with 2016 dollars in cash, which basically nobody does. What's more common is loan financing.
The payment of a 20-yr loan for $15,000 at 4% interest (which is a great financing rate for an equipment purchase) amounts to $1,090/yr, but that is a fixed payment that doesn't increase. The total of payments over 20 years amounts to $21,800 if I were to pay it all out of pocket. Of course, if I use taxpayer money for rebates and subsidies it would be less to me, but regardless of who pays, the costs are the costs and somebody is paying them.
Now if you think the average rate of inflation for electricity will exceed 3%/yr then that would increase my grid-power bill.
By the time it's paid off the equipment will likely be at or near the end of its effective age because these panels degrade over time and exposure to the elements and the constant cycle of heating and cooling, and the batteries have their own limitations with lifespans. As well, most people will be replacing the roof at the same time as their solar because it would be cheaper.
Now as I said, the math works differently for everyone's situation. If you're a single guy who's only home on weekends and at night during the week your energy consumption will be way lower so you can get away with a smaller system, although your grid power usage would also be lower. If you lived inland where it gets a lot hotter during the summer your usage would increase a lot due to using air conditioning (which we don't because we live near the coast).
So a solar install is generally going to be a lot more feasible for someone who has a larger house with an inland location and is home a lot than for someone who's in a smaller home near the coast and is only using power for a few hours a day. That's because the fixed costs of your utility bill remain the same whether you use a lot of energy or not.
I fully expect the costs of the hardware and possibly even the installation to come down a lot as we go. They may decrease by 50% or more in the next 10 years. The irony there is that if you wait to adopt the tech later on your break even point comes a lot sooner and the equipment will probably be more efficient and will have longer component lives. You'll break even the same time the early adopters do, except you'll still have 50% of the lifespan of the components in front of you and they'll have none.
I compare the situation to computers. There are consumers who will buy the latest/greatest computer equipment even though all they're doing is word processing or surfing the web, but regardless how much they pay they only need so much tech to do what they do and buying more is a waste of money. Then there are other people who buy the older equipment, which is still just as effective for their usage but costs a fraction of the price.
Maybe it's worth it to some people to pay extra for the virtue signal factor of having solar at home now, but I'm content to let those people pay extra for all the R&D and just slide in there with the masses when the tech finally does become feasible and there's more competition between the manufacturers and retailers.
