Presented at the 29th European PV Solar Energy Conference and Exhibition, 22-26 September 2014, Amsterdam, The Netherlands SOPHIA CPV MODULE ROUND ROBIN: POWER RATING AT CSOC M. Steiner 1 , M. Baudrit 2 , C. Dominguez 2 , I. Antón 3 , F. Roca 4 , R. Fucci 4 , P.M. Pugliatti 5 , A. Di Stefano 5 , R. Kenny 6 , P. Morabito 7 , M. Muller 8 , G. Siefer 1 1 Fraunhofer ISE, Heidenhofstr. 2, 79110 Freiburg, Germany, 2 CEA-INES; 50 avenue du Lac Léman, 73375 Le Bourget-du-Lac, France 3 Instituto de Energía Solar - Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain 4 ENEA, P.le E.Fermi 1, Località Granatello, 80055 Portici, Italy 5 ENEL E&R, Passo Martino - Zona industrial, 95121 Catania, Italy 6 JRC ESTI, Via E. Fermi 2749, 21027 Ispra (VA), Italy 7 RSE, Via Rubattino 54, 20134 Milan, Italy 8 NREL, 16253 Denver W Pkwy, Golden, CO 80401 ABSTRACT: Within the European funded project SOPHIA, a Round Robin measurement on CPV modules has been initiated. Seven different test laboratories located in Europe between 48 °N and 37 °N are participating in performing measurements of four SOITEC CPV modules. The modules are electrically characterized with different measurement equipment under various climatic conditions. A pyrheliometer and a spectral sensor, based on component cells, are being shipped together with the modules. This ensures that the irradiance and spectrum, two factors with high impact on CPV module performance, are measured with the identical equipment at each site. The round robin activity is being performed in close co-operation with the IEC TC82 WG7 power rating team in order to support the work on the CPV module power rating draft standard 62670-3. The resulting rated module power outputs at CSOC (Concentrator Standard Operating Conditions) are being compared amongst the power rating methods and amongst the test labs. In this manner, a deviation in rated power output between different test labs and power rating methods are being determined. Keywords: CPV module, power rating, CSOC, round robin, performance testing, standardization 1 INTRODUCTION The International Electrotechnical Commission Technical Committee 82 working group 7 (IEC TC82 WG7) is working on developing several standards relevant for Concentrator Photovoltaics (CPV). Two of these standards will be applied and evaluated through this work. These two standards are IEC 62670-1, “Concentrator Photovoltaic (CPV) Performance Testing - Standard Conditions”[1] and IEC 62670-3, “Concentrator Photovoltaic (CPV) Performance Testing - Performance Measurements and Power Rating” [2]. In IEC 62670-1 two standard conditions are distinguished: Concentrator Standard Test Conditions (CSTC) and Concentrator Standard Operating Conditions (CSOC). CSTC are at a direct normal irradiance (DNI) of 1000 W/m² and with a cell temperature of 25 °C. CSOC are at a DNI of 900 W/m², an ambient temperature of 20 °C and a wind speed of 2 m/s. Both, CSTC and CSOC specify for AM1.5 direct spectral conditions, which are described in IEC 60904-3 [3]. While the standard conditions are fixed, the performance measurement and power rating procedures are still under discussion by the power rating subgroup of IEC TC82 WG7. The CPV module round robin presented in this paper aims to investigate different power rating procedures to support the finalization of a power rating standard. 2 SPECIMEN & PARTNERS As test specimens four SOITEC CX M400 CPV modules [4] and one ISE-SOITEC mono-module are used. The full size CPV modules were provided free of charge by SOITEC and were taken randomly from production. The CX M400 modules have an area of 0.32 m² and consist of 98 lattice-matched triple-junction solar cells and Silicone-on-Glass (SoG) Fresnel lenses [4]. The ISE-SOITEC mono-module is manufactured using the same lens and solar cell assembly technology as the full size modules. In contrast to the full size CPV modules, the mono-module has been equipped with two PT100 temperature sensors. In this manner, the lens plate and internal heat sink temperature can be measured. As the SOITEC modules use Silicone-on-Glass (SoG) lenses, the temperature of the Fresnel lenses [5] may have a significant impact on the power rating of the modules. The measured lens plate temperature will enable detailed analysis of such effects and it is expected that the data gathered will help in proposing procedures to IEC TC82 WG7 on how to account for the temperature of the optics in the power rating of CPV modules. The shipment of the CPV modules includes a Kipp & Zonen pyrheliometer for the measurement of DNI and a component cell based spectral sensor [6]. The spectral sensor provides the ability to determine if the spectral distribution of the DNI is sufficiently close to IEC 60904-3 AM1.5 specifications. In this manner, the laboratories can compare this DNI and spectral data data measured by their in-house equipment. In addition, it assures that two factors with high influence on performance - irradiance and spectrum - are measured with identical equipment at each site. This allows the round robin to focus on the comparison of the specific rating procedures rather than on the uncertainties associated with the measurement equipment. Less critical equipment, used to measure meteorological data like ambient temperature, wind speed and global irradiance, is provided by each partner. All partners of the round robin agreed on using the same measurement guidelines. This included mounting and alignment procedures but also requirements for the duration of data collection. The requirements and the alignment procedure are published together with first results in [7]. 29th European Photovoltaic Solar Energy Conference and Exhibition 2012