In my most recent bill I was paying 13.3 cents per kWh (that includes the 4% tax). That's because there are rate riders added to the bill. Some of those riders are monthly (in my case a 75 cent rider for natural disaster expenses on top of my $14.50 flat bill, both with a 4% tax making it $15.86 per month just to stay connected even if I don't buy any power from them). But most riders are consumption based (per kWh) like energy riders and such. When Obama forced many utilities to close some of their coal plants and switch to natural gas plants and such, that was added as a rider to the bill without raising the "official" rate. The same with my power utility having to pay more for natural gas because Biden is blocking some of the fracking leases -- it's added as a rider increase. There are many other rate riders.
The way I calculate it without getting into all the riders is to figure out how much my overall flat rate is (with the riders and tax) because that's simple. For me that's $15.86. Any part of my bill above that is what I call the usage part of my bill, even if part of it is tax. My last bill was $93.82 for buying 584 kWh from them. Since the first $15.86 was the flat fees, my usage was $77.96. Divided by 584 kWh, that's 13.3493 cents per kWh. Because I consumed 1214.9 kWh during that date range (according to my solar inverter) I saved 630.9 kWh, which translates into saving $84.22. But last month was the last month for which I still had gas service for a while. My next bill will be my first true all-electric bill.
Once I realized that every kWh I'd save with solar would save me 13.3 cents instead of 10.4 cents (I think my true rate was 12.9 cents back when I figured this all out before I got solar), that greatly changed the math on how much spending on solar would be feasible.
There are also other variables for whether or not it's feasible for you. Like how many peak solar hours you get at your zip code. How much of your energy consumption is during daylight hours (for that I had to estimate, but it's good to live in the south where most of our A/C is during the day, so less need for batteries, unlike up north where they have heavy energy usage is at night for heating). If your energy usage will change soon (i.e. kids grow up and move out). If you have a lot of soot in the air that'll build up on your solar panels and require frequent cleaning. Etc.
Doing this on your own (or getting a professional solar installer to do it like I did, but only after I researched it heavily so I wouldn't be taken advantage of) is a methodical and pain-staking exercise. But I'm used to doing that kind of stuff in my line of work. And long-term financial planning is important to me, especially after I realized that my energy bills didn't go way down after my kids moved out like I thought they would. That was about the time Obama was closing coal plants and adding pollution fines. That's what took me down the path to figure out how to minimize how much the Dims can harm my finances while I'm transitioning into retirement.
When electric vehicles become a greater percentage of transportation, power generation capacity will be stretched. There will probably be a need to go back to more coal power. Of course power companies could possibly do this if they buy enough “Carbon Credits” from environmentalists like Al Gore who has the carbon footprint of a sasquach, but hey, he did invent the internet.