You have a lot more patience than I do trying to figure out all the variables.
My dad was an engineer and a tinkerer who would probably get into something like solar power just to experiment with it, even though it might not save him a whole lot of money. The technology has come a long way in recent years, but still in its infancy, I think.
Here's another way to look at it. The political class has their bureaucrats and number crunchers always looking for an edge on how to tweak the regulations to increase their grift and take away our freedoms bit by bit. Us freedom lovers have to do the same to give us a buffer from their manipulations. So the less energy I have to buy, the less the Dims' energy regulations mess with me.