Design Construct and Evaluation of Six- Spectral LEDs-Based Solar Simulator Based on IEC 60904-9 Napat Watjanatepin #1 # Solar Energy Research and Technology Transfer Center (SERTT) Faculty of Engineering and Architecture. 1 watjanatepin.n@gmail.com 1 Rajamangala University of Technology Suvarnabhumi Nonthaburi Thailand Abstract—This article presents the optical design of a six-spectral LED-based solar simulator. The study focuses on the measurement methods of spectral match, the non- uniformity and the temporal instability on the test plane. The proposed six-spectral LED solar simulator has an illuminated area of 900 cm 2 and can characterize medium size photovoltaic devices under variable irradiance. The spectral range covered is between 400 nm and 1100 nm which offer the capability of characterizing silicon PV technologies. The evaluation method is in accordance with IEC 60904-9. The Solar Power meter was used to measure the irradiance and a Compact Array Spectrometer and Fiber optic spectrometer were applied for the spectral match test. The irradiance is controlled via LabVIEW which can adjust the power to drive all LEDs in the constant current mode. The irradiance of 1000 W/m 2 was applied during testing. The results found that the spectral match classification is of class B. The non-uniformity of irradiance is of A-class across the illuminated area. The temporal instability of irradiance is capable of reaching class A. This idea is perfectly appropriate for the application of the testing of I-V characteristic of the silicon solar cell. For future work, the author has to improve the spectral match to reach an A Class. Keywords: Spectroradiometer,IEC 60904-9, Six-Spectral, LEDs-Based Solar Simulator I. INTRODUCTION Solar simulator is a light simulation providing illuminations close to the natural sunlight. Solar simulators are used for indoor testing, for example the V – I characteristic of solar cell or the PV Panel performance test. Solar simulator is divided into two types depending on the light source which are the conventional lamp (Xenon-arc, Halogen, Metal halide) and the light Emitting Diode (LED). The disadvantage of the conventional lamp is short life time (~1,000 hours), complex optical device is needed, high power consumption, low luminous efficiency, and high maintenance cost.[1] On the other hand, LEDs have more specific advantage, such as high luminous efficiency, low operating voltage, low power consumption, long life time (~5,000 to 10,000 hours) and absence of complex optical devices. Moreover, the LEDs have specific light spectral, and is easier to control light intensity. In the past decade, many authors have reported on the LED - base solar simulator and showed the characteristic of light generated that harmonizes with many standards (IEC, ASTM, JIS). To name a few, there was a report on a LED-solar simulator with nineteen spectral of LEDs to demonstrate the spectral in the A class with the luminance area of 5 cm in diameter with 1 sun.[1] Another is a solar simulation by eighteen spectral of LED [2] or a LED light simulation by six spectral with the small luminance area of 10x10 cm 2 . [3] Furthermore, the hybrid light source between LED and halogen lamp with a A-class and B-class of spectral match was presented. [4]-[6] IEC 60904-9 is the most popular standard which was applied to define the performance of the solar simulator. The standard listed three categories which are spectral match, non – uniformity of irradiance on the test area, and temporal instability of irradiance for I-V measurements. [16] In this work, the author report on the design and evaluation of the solar simulator prototype based on six different spectral (cool white, warm white, UV 400nm, IR 740nm, IR 850nm, and IR 940nm). The author then applied two types of LED (Chip-on-board, High-power) to be the light source. The aim of this study is to demonstrate that the compact array of our six-spectral of LEDs is sufficient for the generation of high irradiance (at least 1 sun) on the test plane of 900cm 2 , and authorinvestigate the spectral match, non-uniformity and temporal instability in accordance with the IEC 60904-9 standard. ISSN (Print) : 2319-8613 ISSN (Online) : 0975-4024 Napat Watjanatepin / International Journal of Engineering and Technology (IJET) DOI: 10.21817/ijet/2017/v9i2/170902101 Vol 9 No 2 Apr-May 2017 923