Hot enough for ya?
Solar cookers are based on their much larger brethren, solar furnaces -- massive solar structures that focus heat from the sun onto a small area, creating extraordinarily high temperatures. This heat can be used for a variety of purposes, such as hydrogen fuel production, for research that requires high temperatures, even to make nanomaterials.
This solar furnace, located in sun-drenched Odeillo in the French Pyrenees, is the largest in the world. It has been around since 1970 and uses 63 heliostats to reflect the sun's rays onto a 21,500-square-foot parabolic mirror, which concentrates the energy onto a focal point. The furnace can heat up an area roughly the size of a teakettle to over 6,000 degrees Fahrenheit.