From 0.01 to 44 MWp with Concentrix technology

Abstract

Abstract. The Concentrix CPV technology was developed over the last ten years from a laboratory scale to an industrial scale with fully automized production lines and installed in multi MW CPV power plants. This paper describes the R&D work which was required to proceed from first prototypes to industrial products. Highlighted are significant steps to improve the performance of the CPV modules, the reproducibility of the production processes and the reduction of cost of the CPV system. The module efficiency was continuously increased resulting in a module efficiency of 33.8 % for the latest commercially available product and a world record efficiency of 38.9 % for a prototype module. A 44 MW p CPV power plant with Concentrix technology started operation in 2014 and reached a very homogeneous daily average DC efficiency of close to 25 % for 1.5 MW p blocks.

Challenges in the design of concentrator photovoltaic (CPV) modules to achieve highest efficiencies

“…There are other "CPV specific" losses due to temperature dependence of the SoG lens and changes in spectral conditions. 12,253 All these losses are anticipated and are included in the accurate prediction models. Including these losses with the utilization factor, prediction accuracy for AC power production of <2% for a CPV site has been reported.…”

The role of draft facets in temperature effects in silicone-on-glass Fresnel lens applications

“…In this study, Fresnel lenses (Grooves-Facing-Short-Conjugate lenses (GFSC), see [1] and Fig. 2) with constant prism heights are discussed, for which a critical temperature dependency is reported (see literature [1][2][3][4][5] in [2]), involving a change of focal length with change in temperature and a defocusing effect due to different CTEs of the involved materials silicone and glass. Experimental validation of the involved models can be found in [3].…”

“…Both effects will cause light to miss the solar cell at fixed distance (so-called geometrical spillage) in addition to the chromatic aberration of the lens. Gombert points out the high relevance of SOG's temperature characteristics in terms of CPV power plant losses [4]. Hence, a closer look into loss mechanisms with respect to operational temperature is well motivated.…”