A NEW TECHNIQUE TO MEASURE DIRECT NORMAL IRRADIANCE

摘要

A novel technique and system is presented to measure Direct Normal Irradiance (DNI). Unlike generally known DNI measuring devices, the new technique does not use a solar tracker. A reflector is rotated with a rotation module about a first axis and a second axis which account for the daily motion of the sun across the sky and the seasonal shift in sun's path across the sky, respectively. The rotating reflector receives light within a range of rotational positions of the reflector and reflects the light so received towards a sensor. The sensor receives the light from the reflector in a pulsed manner. From the received pulses the DNI is determined.