First thing to think about when getting a power set up for an SHTF event is how much power do you really need. There are so many products that don't require much power like LED lights, smart phones and anything that used AA batteries. In fact for light, a head lamp and several garden solar lights (Walmart sells them for a few buck each) will light a home. And a 40 watt system may be enough. But if you want to run a tv, toaster, or refrigerator you may need 100 times that amount. Most of your need can be better dealt with by other means other than using electricity.