1 Copyright © 2009 by ASME Proceedings of ES2009 Energy Sustainability 2009 July 19-23, San Francisco, California USA ES2009-90321 FRESNEL LENS SOILING CHARACTERIZATION AND EFFECT UPON PERFORMANCE Leonardo D. Banchik, Aaron Sahm, Dr. Robert Boehm Center for Energy Research University of Nevada, Las Vegas Las Vegas, NV 89154-4027 Kenneth W. Stone Amonix Incorporated 3425 Fujita Street Torrance, California 90505 ABSTRACT The Amonix system is a high concentration PV system that utilizes acrylic Fresnel lenses to focus the sun’s rays onto dispersed PV cells. The Fresnel lenses become soiled with dust over time which decreases power performance. Because of the effect soiling has upon the system performance, Amonix and the University of Nevada, Las Vegas (UNLV) have defined a long term soiling investigation and cleaning methodology. The test and measurement procedure for determining Fresnel lens soiling rate characterization is discussed. Lens soiling rate data is presented for different sites that show the soiling rate is a direct function of the angle of the lens. This paper also discusses the test and measurement procedure of the first phase of an on-going Fresnel lens cleaning investigation. An assessment of the soiling rate upon power production is also presented. INTRODUCTION Amonix manufactures a solar electrical power unit that uses the sun’s direct normal irradiance (DNI) to produce electricity. The system is designed to focus the DNI, the beam component of the sun’s radiation, onto high concentration photovoltaic (PV) cells in order to minimize the cost per unit area of solar power systems. Because solar cells are known to be the most expensive component in the industry, Amonix’s design drastically reduces the cell material for each system; replacing it with low cost materials such as aluminum, steel, and acrylic. A picture of the unit is shown in Figure 1. Amonix employs Fresnel lenses for concentration, which are produced by forming facets in an acrylic sheet. These facets redirect the sunlight onto a single cell as shown in Figure 2. In the current system, 1080 Fresnel lenses are arranged in a matrix comprising one module. Amonix has two systems: one with five modules (5400 lenses) and the newest generation with seven modules (7560 lenses). Figure 1 - Amonix System