|Originally Posted By MarkNH:
Ok so he says I can build a 70 watt solar panel for under $200 (plus the cost of batteries, inverters etc).....
Obviously it's dark half the time = no solar, plus about half the daytime it is cloudy/raining etc so you wont get the full 70 watts, so lets say 6 hrs a day we get 60w and the other 6hrs we get 30w, meaning we get a total of 540 watt hours of electricity from one 200 dollar panel,
Divide that by 24 hours in a day makes an average of 22.5 watts output, meaning we would need 4 panels ($800 and a couple of days work) to run a 100 watt bulb continuously.
Full-size 200-225-watt solar modules are now wholesaling for less than $1.00 per watt. Way less. Not just the Chinese ones either (many of which are perfectly good, anyway). I know of entire PV systems (modules, racking, inverters, labor, permitting, everything) for way less than $3.00 per watt. A 70-watt panel for under $200.00 is no bargain, unless you're buying it at the hobby shop in some piecemeal fashion. This stuff has become much cheaper in the last twelve months.