It just depends on how much energy you will need to use at any given time and how quickly you want to be able to charge your batteries. If you are somewhat care

It just depends on how much energy you will need to use at any given time and how quickly you want to be able to charge your batteries. If you are somewhat careful, 5-10kw is enough for many homes, depending upon whether appliances are electric or gas, as well as heating/cooling loads.