Potential for LED solar simulators

LED solar simulators have been discussed recently as a potential next generation solar simulator. This contribution evaluates the possibilities of generating a light field of appropriate spectrum with good uniformity. LEDs have very different optical characteristics compared to standard lights and this needs to be considered in the optical design. The aim in this paper is to achieve a close spectral match to the AM1.5 solar spectrum from 350nm to 1300nm. A total irradiance of 1000 W/m2 needs to be acquired. Additionally, the non-uniformity of light needs to be equal to or less than 1%. The key to mix spectra and achieve the desired intensity and uniformity is the optics. This paper evaluates different optical layouts to assess the potential for fully LED based solar simulators. The TIRs perform better collecting more light than other optics tested.