Prototype of a simplified polar heliostat suitable for integration in buildings

Abstract

The increasing improvement of energy sustainability entails a raise in the use of heliostats in small applications. These devices aim to use direct radiation as a source of natural lighting, and they are also used as components for concentration systems in thermal and photovoltaic applications. Most technological developments published about heliostats up to now refer to concentration tower thermosolar power plants. Furthermore, they are orientated towards heliostats of big dimensions with large distances between the reflector and the focus. It is different, however, for urban applications, where smaller heliostats and lower distances travelled by reflected rays are proposed, and, consequently, greater errors in solar tracking are allowed. This paper describes a new simple heliostatic system suitable for small applications. The main feature of this system is the possibility of controlling several heliostats with a unique engine. It must be highlighted that the system proposed uses a simple logic and has an easy electronic controller implementation.