I haven't posted for a long time now, but I must comment on the collector panels.
Even the 15 watt suckers can give you a nasty jolt when they are are unloaded. They put out a bunch of volts in direct sunlight at the terminals that can knock you off the roof at the terminals. - I know- I just went through that this week and would up connecting - very stupidly - with the unloaded output with the "tame" voltage from the sunlight panels. I damn near got knocked off the roof by the jolt I got.
"Green is good" for now, but and a big BUT, be careful with these so called "docile" panels.
BTW - anyone have any hints on how to earth these things and isolate them from a grid tie system?