Abstract :
Efficiency is the most important parameter for the evaluation of solar cells both in science and in industry. While, in general, the technology of the solar cell is discussed in detail, the question as to how and how well the efficiency value was determined is not examined with the same intensity. The author found that, in general, measurement errors tend to overestimate efficiency systematically. As, for obvious reasons, everybody is interested in high efficiencies, the overestimated efficiency data are readily accepted and published. These “phantom efficiencies” lead to distortions in the scientific and commercial assessment of solar cell technologies. As a consequence, the ISE calibration laboratory has installed a thorough quality assurance (QA) system for solar cell calibration, which is described in detail with many practical examples. The role of frequent comparisons between laboratories as a prerequisite for high measurement quality is pointed out. The “ISE PV Charts” are presented, a list of certified solar cell data, which forms an integral part of the QA system. Finally a “Codex for Efficiency Data” is proposed
Keywords :
calibration; measurement standards; quality control; solar cells; Codex for Efficiency Data; ISE PV Charts; ISE calibration laboratory; efficiency value; laboratory comparisons; measurement errors; overestimated efficiency data; phantom efficiencies; quality assurance; solar cell calibration; solar cell measurement quality; Calibration; Energy measurement; Imaging phantoms; Laboratories; Manufacturing; Measurement errors; Measurement uncertainty; Photovoltaic cells; Quality assurance; Solar energy;
