What if I get my off grid power by kidnapping my neighbors and chaining them to a Conan-style "wheel of pain"? Just hypothetically.
If this is the case, then the reason you were able to obtain those solar panels is because they were made at a factory which fabricated hundreds or thousands of similar panels.
That factory could not have done so unless it had access to traditional power sources such as electricity from massive power plants or oil/gas from massive refineries.
If/when your solar panels begin to fail, then you will need to acquire new ones. Those panels will be much better than the ones you currently have because they were developed and manufactured by companies that also required access to traditional power sources.
But let's say you want to go completely off grid. You could live in a hut in the woods and get your only energy from a waterwheel you built in a nearby stream and wood you cut and burn. This might work in a place like the US where we in general have law and order (at least for a bit longer), but it wouldn't work in places like Central America where you would soon be found out by terrorists or drug cartels and either murdered or forced into being a drug mule or worse.
The society which could theoretically provide someone with a Jeremiah Johnson type lifestyle requires access to massive amounts of traditional energy supplies. You don't get law and order from a few solar panels and a windmill or two.
I have none. I have space off roof for plenty but the ROI at this point is past my “Use By” date. 😎👍
So when the time comes to repair/upgrade components, where will I get the replacement parts? That's the value of the free market. If you get your power only from the grid then you probably have only one option as a local utility, and it is heavily regulated by the state. Thus no free market in getting your power the traditional route. But if I need new solar panels I can buy them from Mission Solar in Texas who made the first ones, or Tesla (too pricy for me), or First Solar (also USA), or Q Cells (Georgia, USA), or Crossroads (Indiana), or LG Solar (South Korea, though for a while they made some in Huntsville, AL), or Aionrise (nation of Georgia, not the Hershel Walker version of Georgia), or Canadian Solar, or many others. The same with inverters and batteries.
And you're right. My return is projected to to pay for the investment on about the 11th or 12th year. That includes the extra in cost for the EV vs replacing my wife's car with another used gas car like we were about to anyway. That also includes all the hookups that go with it (labor for solar installation, hooking up two EV charging outlets, setting up one outlet on a separate load panel that gets powered only when my home solar batteries are charged enough to make it through the night without pulling from the grid, but have another 240V outlet to charge the car with constant power if the EV is low on charge, etc.). That calculation assumes only a reasonable 3% inflation rate in the energy costs I'm mainly avoiding (price of natural gas, power, and gasoline). Obviously if the Dims keep having their way and energy has a higher inflation rate then my project pays for itself sooner. That's also paying interest on both the EV as car payments and on the HELOC loan I took out to pay for the home energy improvements and solar equipment and installation. That payoff calculation accounts for savings at the gas pump and oil changes (also assuming a 3% inflation rate), but having to replace the EV battery in 10 years, but also not having to buy yet another used car on average every 7 years like we've done for many years for $10K (today's prices).
That also assumes a gradual decline in energy production and storage with my solar panels having a 25-year warranty guaranteed to still be producing 70% in the final year (half of my panels guaranteed at 80% in the 25th year), and my home batteries having a 19-year/50% warranty. Hopefully I won't need to replace any solar equipment before the payback is done (it will cost me labor but not parts). If I'm right then the remaining years the equipment lasts past the payoff is icing on the cake.
But that's not as important as the fact that this project has shifted most of our variable future energy expenses into fixed costs. I went from wondering how much energy price inflation would eat up our retirement investments, to paying a fixed HELOC payment and for a few years a fixed car payment (for the EV). Basically it allows me when I begin retirement in a few years to keep my Roth IRA/401K investments more aggressive than I normally would have because it'll cost a lot less to power our house and drive around. I told my wife that I'll still pull the same $450/month from our budget that we were spending in year 2019 for power bill + natural gas bill + gasoline to drive one car ~200 miles/week (back when both of us worked full time and commuted to the office, but today count only 1 car's worth to relate to driving around now with one person retired and one person working from home a lot). The only thing is I'm now using that $450/month to make the HELOC payment (after taking out $30-ish to pay the tiny power bill). When the HELOC payment + power bill is well under the $450/month (because the HELOC minimum payment goes down as the balance is paid down), I'll put the excess into a simple investment account just for future solar maintenance/upgrades. (The interest rate on the HELOC is low and fixed, might as well get a decent return in simple mutual funds instead of paying down a low interest rate loan.)
Dig this: the energy portion of our budget will forever be like it's year 2019. In year 2040 (when my first batteries' 19-year warranty expires), the investment account will have $54K (assuming 10% annual return) and I will have saved $61K on top of that in my retirement investment accounts by virtue of the fact that I will draw only $450/month from them for our energy budget (vs the higher and higher energy costs I'm avoiding). Obviously I'll pull more than that from retirement accounts for other costs of living, but this post is about energy costs. I wish I could make all inflation go away in my budget, but I'll settle for making energy inflation go away.
Will $54K be enough to replace my batteries in 18 years? I dunno. So far solar equipment is like computers in that as the years go by they go down in price relative to throughput. (This year they went up in price like everything else because of Brandon.) So a future battery stack capable of at least 92kWh storage and 86kW of power on demand at any time might be cheaper in 18 years like data processing power and storage is cheaper per gHz and TB than it was 18 years ago. The same with solar panels.
What if I get my off grid power by kidnapping my neighbors and chaining them to a Conan-style "wheel of pain"? Just hypothetically.