Elmo Dutra Eng, MSc, is a professor, and researcher in solar energy since 2000, with particular interest in solar cooking working in southern Brazil in the state of Rio Grande do Sul. He is the founder of Fogão Solar, and has developed the Fogão Parabólico parabolic solar cooker. He works with his students to create new projects, and also offers solar cookers from other manufacturers for sale through his website.
He also has been experimenting with his own heat-retention cooking device. A cardboard box lined with polystyrene insulation and surfaced with reflective film. And using a standard pressure cooker preheated, and placed inside.