This is a short, technobabble-lite description of how I designed, purchased, assembled, and utilized a solar photovoltaic system to power a Burning Man camp. This article will tell you most, but not all, of what you need to know to use solar electric power at your own encampment (whether it be at Burning Man or elsewhere). I hope you enjoy this information. Please feel free to contact me with any corrections or suggestions at jason(at)coopersco(dot)com

Design: Basically, you need to figure out how much power you will use, how much you will bring with you (in the form of charged batteries), and how much you will need to generate. My system powered a small water pump (for the Mist Tree pictured with the author here), some Christmas tree lights, a car stereo, and some other lightly used devices. All of the devices I used were 12v, so calculating usage was pretty easy; I multiplied the number of amps the device consumed by 12 (the voltage) and to get the watts used, then multiplied by the number of hours the device would be used to get the watt-hours. I added up all my watt-hours to get the total amount of power I planned to use. (The basic equation that you use in many electrical calculations is amps = watts / volts. You can rearrange this equation to suit your needs, like amps * volts = watts or volts = watts / amps).

Some of you will want to power 120vac devices like you plug into your home outlets. To do so you will need an inverter; this device converts the 12v direct current supplied by batteries into 120v alternating current. I bought a cheap one at Fry's and it worked well for my needs (charging power tool and AA batteries, powering a stereo receiver/amp).

Next I calculated how much power I would bring in the form of two heavy-duty 6v lead acid golf cart batteries. Each held 360 amp-hours at 6v, for a total of 360 amp-hours at 12v, which we can convert to 4320 watt-hours using our handy equation above (360 * 12 = 4320). In the previous step I calculated I would consume a total of about 6,000 watt-hours during my stay at Burning Man, thus requiring that I generate about 2000 watt-hours (6,000 - 4,320 = 1680).

I selected 6v golf cart batteries because they are much more tolerant of deep discharge cycles than normal car batteries. However, car batteries will work just fine for the short periods that most of us use our solar systems, so if you've already got a car battery or two you can use those instead.

To generate this power I used a 120 watt solar panel made by Astroworks. I connected it to the batteries with a charge controller, which also provided me with a panel output meter (so I could see how much of the rated 7 amps the panels were actually generating), a battery charge level meter (so I could see how much juice I had left in the batteries), and short circuit protection (which disconnected everything if anything went wrong). You don't strictly need a charge controller, but I'd highly recommend one for all but the most simple systems.

The panels were rated to output 7 amps at 12vdc in full sun. I figured that I could keep the panels in full sun for about 5 hours a day, thus generating 420 watt-hours each day (7 * 12 * 5 = 420). I needed to generate about 2000 watt-hours, which meant I'd have to keep the panels in the sun for about 5 days.

As Burning Man progressed, I realized that while I was generating about as much power as I had anticipated, I was using more than planned. I had to connect my batteries to a generator (via a 12v charger normally used to charge car batteries) a couple times. This use of fossil fuels in an alternative energy system was unfortunate, but bringing a 12v charger does provide you with an easy and effective back-up to under-generation/over-consumption during your stay in the desert. A little red wagon was also very useful for moving the heavy batteries to the generator and back.

Hopefully this is enough information to get you started with your alternative energy system. I am far from an expert on this subject so please let me know if I've made any major errors!

Thanks for reading!

Jason