We play on making the Mirrors and Glass sunlight heat box it will go over 240F and be able to boil water into steam for our steam powered tubine that will power our pyramid building. We have made videos of the sunlight trape solar heat box they can be viewed at "Click Here for videos on the Sunlight Trape Heat Box":http://www.youtube.com/watch?v=uC95i-367-

The invention already exists, although in a different shape:

 

Vacuum tube solar heaters are already used and produced on a large scale. Wikipedia also has a page about it (of course).

 

You describe in the video that you have 10 layers of glass. These will provide a very effective insulation. The glass prevents convection (movement of air), which is exactly what you want.

The commercial product uses a vacuum to prevent movement of air.

 

If you just take a vacuum tube solar heater, and you use some mirrors to concentrate the sunlight a bit more, then I'm sure you can easily produce steam.