I got my solar sensor light from Real Goods Catalog. It's been on a shed for over a year now still works. I live in NE Wisconsin, so it doesn't get much charge on overcast winter days, but it will still kick on for 30 seconds or so. On sunny days it gets a good charge and will last for my boiler stoking activities, which is all I wanted. It's very bright and the sensor adjustment works perfectly. I mounted the solar plate to a moveable pole in case I needed to move it depending on tree shadows, etc. but I haven't had to yet. Someday I'll build a mounting bracket to attach it to the side of the shed so it sticks up over the roof, although it is nice having it at ground level so I can easily brush the snow off of it.

Pal

Here is a link that might be useful: Real Goods Solar Sensor Light