Build Your Own Solar Electricity System For $600
By James Grahame
So you want to try out solar electricity, but you don't want to spend $30,000 to retrofit the entire house. Why not start with a single room instead? Rex Ewing has written an interesting piece that details how you can assemble a complete solar electric system for not very much money. Because it includes a single 32 Watt PV module, the basic system can only generate about 1 kWh of electricity a week.
"Fifteen minutes of surfing on the Internet turned up the following items. I’m sure a more thorough search would produce even more favorable results:
One Uni-Solar 32-watt amorphous-silicon PV module, 12 volts: $180.00
One Morningstar 6-amp charge controller, 12 volts: $40.00
Two Deka 92 amp-hour sealed batteries, 12 volts: ($130.00 each) $260.00
One Aims 800-watt modified sine wave inverter, 12 volts: $65.00
This leaves you with $55 for wire, battery cables, mounting hardware, fuses between components, and the miscellaneous odds and ends that are always needed for any project of moderate complexity."
1kWh (1000 Watt/hours) per week isn't much, but it's enough to run a small TV for 20 hours or power a laptop for 40 hours. With some careful planning you could probably take an entire bedroom or part-time home office off-grid. The system can be expanded with up to two more PV panels and additional batteries, although you'll probably need to replace the inexpensive 800W AC-DC power inverter with something beefier.
By the way, if you're looking for an affordable device that can measure the amount of power your various gadgets and gizmos gobble, check out the UPM Energy Meter we profiled a few month ago.