I don't remember where I read it, so no link, and it was some years ago, so I doubt this specific design was tested. A website did a review of some homemade cookers, alcohol stoves, solar cookers, anything really. The one to boil water the fastest, was a solar cooker made with a windshield reflector for a truck. Just a short cut at the bottom to fold 90 degrees, some stuff to set the pot at the focal point, and an easy to make solar oven from stuff you can find out of cars and stores. (I don't think looters go for windshield reflectors that much)