Solar energy is a dilute form of energy, to achieve temperatures above 90°C, the concentration of Solar radiations is must. Various types of concentrators are developed, namely Concave reflective, Convex transmissive, Fresnel lens based, Cylindrical line focusing or Spherical/Parabolic point focusing and so on. All these concentrators, depending upon the concentration ratio and overall system efficiency, achieve the higher temperatures up to 1000 °C. To aim the focal point of concentration on collector device as per the Sun’s movement (Hourly, Daily and equinox based), the tracking of concentrator either uni-axial or bi-axial is required. This tracking mechanism involves servo motors with gearbox, control system and robust mechanical structures which will enable precision tracking and withstand the atmospheric conditions.

To have a long effective life, tracking system demands periodic maintenance, uninterrupted power supply which is a challenge when used in developing world or remote places. So to overcome these limitations a TRACKING FREE SYSTEM is suggested which will concentrate the solar radiations to a point.

The benefits of this device are listed below.
1. Elimination complex structures, electric drives, Controllers etc
2. Reduction in maintenance cost. (Almost Zero)
3. Reduction in initial investment. (90%)
4. Simple & User friendly system.

As shown in illustration 1, the concentrator suggested is basically a “Out type Fresnel lens,” Cylindrical type which is curved into a Cylinder which focuses on a line,. There is second similar concentrator, “In” type is placed inside with focus axis perpendicular to outer. So both concentrators together achieve a point focusing (illustration 2). The 360° cylindrical shape covers the hourly/ daily tracking of the sun. The angle of inclination(?) towards South can be optimized to the Latitude of a particular place to achieve the maximum collection as per need. To eliminate the tracking for equinox based Sun’s movements, the Collector tube is kept long and inside structure is shown in illustration 3. This long tube covers the entire trajectory of focal point due to equinox movements of the Sun. Evacuation of the collector section will enhance the efficiency of collection.

These concentrators can be made in Polycarbonate extruded sheets which are then wrapped in cylindrical shape “Along” and “Across” the Fresnel prism directions supported by simple steel frames. Outer concentrator, the angle of Fresnel Prisms will be all same. When curved, it will increase to match the focal point. So this is to be optimized with shape and material for every application. Inner concentrating Fresnel prisms will have different(increasing towards edge) angles to match focal point. The collector tube can be a circulating fluid type working on Thermo-Siphon or Heat pipe which will collect the heat in a reservoir as per the application. As the concentration enhances the efficiency dramatically this can be a good substitute for all the existing solar applications and will add to wide usage in Industrial segment where higher temperatures are demanded. The cost of this product is expected to be same as currently available non-concentrating type collectors.