Eco Lifestyle Bills

I still dont understand why we are paying for what we have already bought. I dont mind big bills, money has to go somewhere. but paying for what I bought doesnt make sense, it doesn't happen in real life so why in the game. when I go to replace it I dont get what I bought it for, yet i still pay taxes on what I already have.

I finally have enough solar panels and underground water surplus to negate the water and electric charges. My lot tax is the same despite the increase in home value. So, I guess I've made an eco difference and am just stuck in the low lot tax situation. I'm not complaining about it. Being a conservationist is not great for the bank account.