The problem of this "easy" method is that it does not scale: if everyone was doing it there would be much more problems to manage: renewables are not continous

The problem of this "easy" method is that it does not scale: if everyone was doing it there would be much more problems to manage: renewables are not continous (storage needed), we do not have near enough capacity yet, the grid may not be designed for decentralized production, etc. edit: also it is very rare to have the externalities included into the sum of CO2 emissions (dams need cement, wind turbines need steel, solar panel need mining, we need to transport these components, etc. -> all of that is probably not currently powered by CO2 neutral energy).