A stationary concentrating collector is a type of concentrating collector that uses compound parabolic reflectors and flat reflectors for directing solar energy to an accompanying absorber or aperture through a wide acceptance angle. The wide acceptance angle for these reflectors eliminates the need for a sun tracker. This class of collector includes parabolic trough flat-plate collectors, flat-plate collectors with parabolic boosting reflectors, and solar cookers. Development of the first two collectors has been done in Sweden. Solar cookers are used throughout the world, especially in the developing countries.