The prototype collector has an aperture area of only 2 m2 with a width of 1 m and a length of 2 m. Consequently it is lightweight and can be easily used for roof installation. The rotation axis is equal to the absorber tube axis, so that the absorber stays in a fixed position during process while the parabolic body rotates around the absorber tube. Therefore there is no need of expensive flexi­ble pipe connections. The collector consists of a stainless steel body, an evacuated absorber tube, a high-reflective aluminium mirror from the German manufacturer ALANOD (4200 GP Miro-Silver 2) and an anti-reflective solar glass cover from the German manufacturer FLABEG. For actuation and tracking the sun, a step motor drive with worm gear and a sensor is applied.

The aspired operating temperature level is 120 to 200 °C. The power is about 1 kW per module and the collector has an efficiency of around 63 % at solar direct radiation of 800 W/m2 and a tempera­ture of 160 °C. Measured at the collector test facility at the SIJ, the illustrated efficiency curve of Fig. 1 with an optical efficiency of q0 = 0,7 and a linear and quadratic heat loss coefficient of a1 = 0,204 W/(m2K) and a2 = 0,0015 W/(m2K4) was determined: