Ok, so is all the energy from the sun absorbed by the earth? where does the excess heat go from roasting the beans? Is it absorbed by the earth? Too many variable for my brain... but fun to discuss.
I honestly don't know ether way, and your point is a good question?
Another question: Is this solar roasting really carbon neutral? How much energy is spent building the solar panels, the mirrors and other goodies for this roaster and over the life of each part do they save more fossil fuel than was used to create the "green system"?
Either way it's still a cool roaster!!