Don,
Thanks for the link.

Robert,
After checking out the web site provided by Don, I'm pretty sure that Lake Waco does not have a Solar Bee system. There are two units, one is a shore-based system on the North Bosque River and the other is a submerged system by the dam. Neither one looks remotely like the floating ones advertised on the Solar Bee site.

That said, they look pretty interesting. The biggest limitation I see is that they only run when the sun is out, exactly when the lake is already producing oxygen. They apparantly can be modified to run at night and on cloudy days, but it requires a shore-based power supply. The cost of the unit would have to be fairly close to an electric system for me to be interested.

Plus, 16' in diameter! I guess that would qualify as adding structure to your lake? :p