Has a solar powered toaster been invented yet?

Question

It sounds like it would be a good idea, but has it been done yet?

Answer 1

The best idea thus far is to mount a solar collector on the roof and just plug in the toaster.

Solar powered toasters themselves would be impractical because of the size of the solar panels. A toaster generates, say, 500 watts of power. Sunlight has about 2 watts per square centemeter. One might think this means a solar panel with an area of 250 square centemeters would supply the power needed, but unfortunately no solar cell is over 10% efficient. This means the panel would have to be 2500 square centemeters. This would be a square panel 50 cm on each side, or roughly 20 by 20 inches. Even a pair of 10 by 10 inch panels would be a bit cumbersome on a kitchen appliance. Besides making it look like some sort of satellite, the toaster would only work on sunny days.  Far better to just hitch an electric motor to an exercise bicycle and generate toast using your own energy.

Of course another way of making toast is to use sunlight directly. A large frenzel lens can generate enough heat to melt copper. If the beam were projected into a small oven, then perhaps toast could be made. The tricky part here is controlling the amount of heat. Also, a lens big enough to heat an oven is about 2 by 4 feet.