Let me try again to explain entropy. You have tons of renewable energy systems in The Villages. They are called solar pool heaters. You are correct it takes oil and it takes energy to refine it, make the plastic and mold the plastic. How much does this energy cost, I don't know but since I know of no subsidies for solar pool heaters I think we can guess it's a small part of the purchase price. Purchase price will include other costs, labor, taxes, profit to name a few. They are renewable energy because they turn sun light into hot water. It would be much simpler to hook you pool up to your hot water heater and use coal derived electricity. I'm sure if you talk to your neighbors they will say the solar heater payed for itself many times over compared to an electric heater. Some day the solar heather will wear out, it will start to leak and not be fixable. You can't get the entropy back out of the system because their is no good way to turn the solar heater back into oil and unlock the energy used to make the plastic. However it is such a insignificant cost you don't care. A solar pool heater and a windmill are the same concept, turn one form of energy into another.