Contribution to the design of a Parabolic trough collector with composite material using GRP pipes scrap

Abstract

The world revolution is moving towards a low-carbon and sustainable development. When environmental costs and considerations of security of supply are included, renewable energy becomes the alternative to be considered. Among renewable energies, Parabolic Trough Collector power plants constitute the biggest share of the installed concentrating solar power technology. The bearing structure is the most expensive part of a parabolic trough power plant. It has the function to carry the mirrors in the right position, to give stability to the troughs and to allow an exact Sun tracking. To fulfill these functions, structures must meet certain requirements. In particular, the stiffness requirements are very high. It’s obvious that an inappropriate carrier structure should involve additional material and manufacturing costs. Composite materials have great potential to be suited for development of renewable energy structures. It refers to any structure with two or more distinct materials that are combined to create an engineered product with properties greater than the sum of its parts. Glass reinforced polyester (GRP) with E-glass as the reinforcing fiber is the most common form of composite construction. GRP pipes scraps derived from cutting process can be revalorized and used in the bearing structure of a parabolic trough. The advantage of these materials lies in their high mechanical strength, corrosion resistance and low density compared to metals. Additionally, their high stiffness allows longer troughs so that the number of pylons and tracking units can be reduced, which reduces costs. The stiffness of GRP pipes combined with lightweight structure allows the use of weaker foundations and monitoring mechanisms. A lightweight structure is also less susceptible to deformations generated by its own weight. In addition, light structures reduce the energy demand for collector tracking.