Go Solar, Or Go Home

Last modified on July 27th, 2009

I’m up at Cultus Lake now, doing some weird cross between camping and working. I honestly wasn’t too sure if I’d get 3G up here, and had planned to head back into town during the days. But given how I have four bars on my phone, and that 3G is working great, I might just work from up here.

Solar Laptop

To that end, I went back home a while ago and picked up my 15W solar panel and my 75Ah deep cycle battery. Right now my laptop appears to be drawing about 25W, which is fairly awesome considering I’m charging it and also working on it at the same time. At 120V, that means it’s currently drawing roughly 0.2 amps (200 milliamps). I’m currently using an inverter attached to the deep cycle battery, and since power must be roughly conserved across it, that means the battery must be putting out roughly 2 amps at around 12V. Since its capacity is 75Ah, that means it should be able to power my laptop in this configuration for appoximately 75/2 hours, or 37.5 hours.

When the solar panel is in full sun though, it puts out around 15W at 12V. The delta between the two is about 10W, which means that the battery is still putting out a difference of about 0.8 amps. At 75Ah, that means it will roughly last for around 93 hours, as long as the solar panel is in full sun.

Either way, I think it’ll be enough to last me for three days up here. Which means I can work from the comfort of my picnic table here. This is the first time I’ve used my solar panel like this, but it’s been something I’ve always wanted to try. I’ll put a few more photos up later, once it cools off a bit and I’m motivated enough to whip my camera out.