Designing a parabolic trough solar concentrator requires specifying:
• the collector aperture,
• the focal length,
• the size of the tube located at focus,
• the degrees out of focus possible before the trough needs to be refocused.
This Demonstration was written to aid in the design of hand-operated solar peanut roasters for use in developing countries. The material in the tube can be peanuts for roasting, bread for baking, water for heating, etc., or simply air to be heated for drying crops. All dimensions are in millimeters.
Three pdf documents that describe the performance, construction details, and overview of a parabolic trough solar concentrator are available at Solar Roaster.