INTRODUCTION

This project outlines the technology of a new solar collector and concentrator particularly adaptable to concentrating photovoltaic systems.

The basic economics of solar concentration are simple: replacing costly semiconductor solar cell area with low-cost solar mirrors, thus the solar cell area is a small fraction of the total collector area.

The concentrated sunlight gives greater power output per unit area of silicon compared to the flat-plate systems and allows more efficient use of limited supplies of high purity silicon feedstock.

The project relates to the linear receiver technology, where line focus tracking reflectors concentrate sunlight onto receiver modules along their focus line. The linear focus allows tracking the apparent movement of the sun with only one degree of freedom.

The collector and concentrator basically consists of an array of long metal foils with a reflective surface, longitudinally tensioned from both free ends by respective end moving frames with tensioning means.

The basic concept for the design is that a metal foil, when placed in uniform tension, provides an excellent substrate for an optically reflective surface.This technology is directed to avoid the use of longitudinal support structures normally used for supporting the mirrors and allows substantial weight and cost reduction compared to more conventional technologies like parabolic troughs, for example.

The lowest cost route for developing concentrator systems is to use low-level concentration, as little changes have to be made in the manufacturing process of the standard one-sun cells.

The technical and economic feasibility of a concentrating photovoltaic system with low-level concentration and a metal foil collector-concentrator is outlined in this report. Significant weight reduction and potential cost saving over existing technologies is also demonstrated.