I've a friend who is working on this exact problem. He currently uses small generators, but doesn't want to keep filling the dang things up. He too is using PCs for watching remote locations, like construction sites.

I've hooked him up with my PV electrician who thought he could put something together, depending on the voltage, amperage, and watt hour requirements, for 'bout 300 bucks. But since he is already running PCs using generators, he's using DC, so I'll ask him next time I talk to him about his power conversion hardware.

I should think you could get that cost down, as we've talked before, by trying to get your hands on used stuff. E-Bay? Oh, also try an RV place...they've tons of stuff that runs off DC...might have what you are looking for. I wonder if those little battery-backup units can charge using a DC input? Or could they be converted to use DC? You'll know the output is correct that way.

If you start going with an inverter, make sure you get one with a fairly clean sine wave output and AC cycle...otherwise you can mess with some computer power sources...or so I've heard. And, as was mentioned, inverters consume watts.

There are small solar chargers for laptops, I think Brunton makes one, check the REI website...they run almost three hundred bucks, though. Don't think you could run all night on the battery on a laptop, though, unless you kept going in and out of hibernate just to collect an image. Are you going for continual video recording? Motion detection? An image every X minutes? Internet tied?

~jms~

PS...about your water storage problem...I was musing the other day how much water is in our sprinkler system when I have to drain it. How much water can you store in pipes arrayed for just that purpose? If there is even a small grade, you could have large diameter pipe at the uphill end and progressively smaller pipes towards the bottom, thus producing a small increase in water pressure. I haven't done the math yet, but it might be worth some back of the envelope calculations.