Patrick Luckow

Portable Solar Power Kit

For about $180, I brought together all the components needed to power a typical laptop for a couple hours solely on solar power. It's great for emergencies, or just knowing you are powering something real with a completely renewable resource.


This kit weighs about 2 lbs, costs $180, and will power my Macbook for 1.75 hours (1.83ghz, browsing the web and checking email via Airport Extreme, bluetooth off, screen brightness about 70%) with a little more than 5 hours of good sun. Here's what it takes:

Solar Panel

I bought my panel on ebay for $80. It's a 15 watt foldable panel, weighing 1.6 lbs with folded dimensions of 10.5" x 8.5" x .75". Easy to stuff in a backpack, to say the least. It outputs power via an SAE 2-prong trailer plug.


Better: Sunlinq 25W Foldable Panel. The included accessory kit means you don't need to buy any more cables, but it's prohibitively expensive at $374 Cheaper: Build your own.

Power

I like the Powerpacks offered by Xantrex, because they bundle a battery and an inverter into one package, meaning there are fewer cables to connect and it's easier to use. I got a Powersource Mobile for $95 from Amazon a couple weeks ago; they've since raised the price, but you can find it elsewhere for about the same. It weighs less than a pound, has a 4 amp hour lithium ion battery, with a three pronged AC outlet as well as two USB ports.


Better: Powerpack 600 HD. With 3 AC plugs, a built-in flashlight and radio, and a 28 A-hr battery, you can do a lot more with this. It only costs $130, but it weighs almost 30 lbs.
Cheaper: Xpower Pocket Power Pac 100. It's a little clunkier, but has a 3.3 A-hr NiMH battery and is almost as compact as the Powersource Mobile, for only $65.

CLA Adapter

To connect the solar panel to the battery, you're going to need an adapter to go from the 2-prong trailer plug to a cigarette lighter. You can buy it alone for about $5, or you can buy an accessory kit with a few other nice cables for $18.


Closing Thoughts


If you plan to let this sit for days on end, or plan to get a solar panel with more wattage than I had, I would highly recommend getting a charge controller to prevent damaging your battery.

Through trying this out, I found that it is very hard to get 5 hours of good sun in Chicago in the winter. It's a great feeling when it works, but not practical for day-to-day use.

While the folding panel itself is small, unfolded it's fairly large. The best places I found to lay it out were on a roof or in a park.

I would really like something even easier to use, such as a backpack with solar panels on it. Voltaic solar bags are close, but not really practical for powering a laptop. Yet. (Update, Jan 08: it looks like Voltaic is almost there, with their new Generator)

Links on the web:
Experience.com Energy Blogging Challenge
Treehugger.com story
Digg.com promoted story

© 2008 Patrick Luckow