A New Design Approach for Solar Concentrating Parabolic Dish Based on Optimized Flexible Petals

Lifang Li Ph.D. Candidate School of Mechatronics Engineering Harbin Institute of Technology 150001 Harbin, China. [email protected] Steven Dubowsky Professor Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge, 02139 MA. [email protected] Abstract Large parabolic dish concentrator mirrors are an important component of many solar energy systems. They need to be relatively precise and are expensive to fabricate and to transport. Here, a new concept for designing and fabricating large parabolic dish mirrors is presented. The dish mirror is formed from several optimal-shaped thin flat metal petals with highly reflective surfaces. Attached to the rear surface of the mirror petals are several thin layers whose shapes are optimized to have reflective petals form into a parabola when their ends are pulled toward each other by cables or rods. An analytical model to optimize the shape and thickness of the petals is presented. The validity of the concept is demonstrated using Finite Element Analysis and laboratory experiments. The concept would permit flat mirror elements to be easily fabricated and efficiently packaged for shipping to field sites where they can be assembled into the parabolic dish concentrators. The concept has the potential to provide precision solar parabolic solar collectors at a substantially lower cost than conventional methods.