After reading arleigh's reply (above) in the Solar panels on roof? thread, I began thinking of something. Pico PSU's. Rather than going DC (battery) to AC (power inverter) to DC (CPU power), why not just go DC to DC to power the computer, and "cut out the middle man"? Pico PSU's are one way to certainly do that. They plug directly into the ATX socket on the motherboard. They also have the appropriate connectors for your peripherals you will need for your specific machine. A Pico PSU uses considerably less power and runs quite a bit cooler than a standard ATX power supply. You could, in fact, easily power it directly off solar. A single panel, a small controller, a couple of (smallish) deep cycle batteries, and a Pico PSU rated for your specific power needs, would be all you need to power the CPU. (Calculations, of course, would be necessary for your specific power / system up time requirements.) Anyway, just turn off the monitor and speakers when you are finished with your computer, and you could leave it running 24 / 7 / 365, for cheap. Just a thought I wanted to share.