Speaking of building regulations and solar, I stayed in a house that was completely powered by solar and wired with DC for lights and electronics. You can't just add an AC outlet in the kitchen for a coffee grinder, though. If you have even one AC outlet, you have to wire the entire house to code -- useless and unused AC outlets every few feet along the hallways, AC outlet in the bathroom even though the inverter can't handle most of the things (e.g. hair dryers) that would be plugged in in a bathroom.

What poor person is using a coffee grinder is sort of my original point.

Coffee grinders are ten bucks and beans last longer if they're not ground.

Also, everyone has the things that they choose to splurge on, even a poor person. When I was dirt broke in college I still bought 2 ply tp because dammit life is too short to deal with anything less. I don't regret it.

Huh? Whole bean coffee doesn't cost any more and some grinders are quite cheap? The vast majority of poor people have smartphones, and those are much more expensive.

Solar is probably a bad example because it's likely to be net profitable.

No, it makes the upfront cost of a house more expensive, it is a fine example.

Basically nobody buys a house outright, so they're not paying the upfront cost anyway, they're taking out a loan. Taking out a larger loan so that you have a larger loan payment when the increase is less than the amount the panels save you in buying electricity from the power company doesn't cost you anything, it turns a profit.

Being forced to pay for a parking space even when you don't own a car costs you rather a lot.

Those are much better examples that the electrical outlet in the garage.