Solar Tracking Skylights

Here are some actual product shots.

I've been absolutely fascinated by these for a while now. They're basically a 4'x4' skylight. The innovative aspect of them is that they use mirrors to reflect sunlight into the building more effectively than traditional passive skylights. the units achieve this with the use of a solar powered motor and sun tracking system. The unit can track the sun at an angle down to 10 degrees above the horizon.

The other huge benefit is that it doesn't produce heat in the same way that a conventional metal halide or fluorescent light would, so your cooling load is significantly reduced. On a sunny day it produces the equivalent of 800 watts of fluorescent light. At 3.4 BTU's per watt that's about 2,700 BTU's an hour saved on your cooling bill. How much is that? A 12,000 BTU (1 ton) air conditioner is enough to cool down a normal sized 2 bedroom apartment during the summer.

It's also reported that when used in retail locations sales increase by 10-40%; in industrial applications employees call in sick less, are more productive, and are less accident prone; and in comparison to no daylight classrooms, classrooms fitted with this device notice a 6-20% increase in grades (that one is the most suspect though). When you think of how good it feels to be outside in the sun and how terrible winter light (or lack there of) can feel none of these results are that suprising.