Shazam,
I would go the traditional route of serious off grid users. Buy a true sine wave power inverter and use 12 volt DC deep cycle (RV/Marine type) batteries. That will allow you to use your existing 120 volt AC equipment without deriving power from the grid. You would use a solar panel (cheap) or windmill (not so cheap) and a controller to charge the batteries. With the batteries charged you can run the inverter and to listen to your system. Keep in mind that several high end companies make power regeneration systems that are effectively taking ac power from the wall and regenerating it with a true sine wave inverter. You will get the same effect here - clean AC, but with the bonus of not using power from the grid. You must use a true sine wave inverter - not the cheap units at Wally mart or you could damage your equipment. If you want to use car audio amps, they can run from directly from the batteries and everything else could run from the inverter which would require a smaller inverter. If interested in this method, I can help with details and/or point you in the right direction. I've done it and still have the equipment.
I would go the traditional route of serious off grid users. Buy a true sine wave power inverter and use 12 volt DC deep cycle (RV/Marine type) batteries. That will allow you to use your existing 120 volt AC equipment without deriving power from the grid. You would use a solar panel (cheap) or windmill (not so cheap) and a controller to charge the batteries. With the batteries charged you can run the inverter and to listen to your system. Keep in mind that several high end companies make power regeneration systems that are effectively taking ac power from the wall and regenerating it with a true sine wave inverter. You will get the same effect here - clean AC, but with the bonus of not using power from the grid. You must use a true sine wave inverter - not the cheap units at Wally mart or you could damage your equipment. If you want to use car audio amps, they can run from directly from the batteries and everything else could run from the inverter which would require a smaller inverter. If interested in this method, I can help with details and/or point you in the right direction. I've done it and still have the equipment.