VOL. 8, NO. 3, MARCH 2013 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences © 2006-2013 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 169 EXPERIMENTAL AND THEORETICAL DESIGN FOR A NEW ARRAY MICRO-LENSES SILICON SOLAR CELL CONCENTRATOR Ali H. Al-Hamdani Department of Laser and Optoelectronics Engineering, University of Technology, Bagdad, Iraq E-Mail: ali_alhamdani2003@yahoo.com ABSTRACT In this paper, a new model for array of micro-lenses concentrator was designed. This concentrator consists of array of micro-lenses (MLA) to focus solar light on four rectangular slaps of photovoltaic Si solar cell. The design aim to reduce the cost of the concentrators by reduces the effective area of the high cost silicon material area and simplified the structure of the system. The solar cell with the MLA- concentrator adds energy conversion efficiency (11.98%) and reducing the total cost. Keywords: solar cell, concentrator, ray tracing program, cell efficiency. INTRODUCTION Silicon-based photovoltaic (PV) convert less than 20% of incident sunlight into electrical energy. High- efficiency solar cells developed for the space industry have demonstrated more than 41% conversion efficiency by layering multiple semiconductor junctions that capture large portions of the solar spectrum [1]. Fabrication and material costs limit these cells to only a few square centimeters, making them impractical for flat-panel installations. Concentrator photovoltaic (CPV) incorporate large-area optics that collect and deposit energy onto small, efficient solar cells with the promise of reducing electricity-generation costs compared to silicon-based PV [2]. For CPV systems to be cost-effective, the complete cost of the optics, assembly and mechanical tracking must not exceed the cost savings gained from using small area PV cells. Solar ray tracing programs was used to find new types of solar lens concentrator to save the cost by reducing the area of PV cells [3]. High-flux concentrators typically consist of a large primary optic to focus sunlight and a secondary optical element for flux homogenization. A common design approach divides the upward-facing primary into several small apertures, each with its own individual secondary element and solar cell [4]. The energy issue has been gaining a lot of attention in many countries in recent years. Among the kinds of energies, the solar energy is one of the most interesting topics of them. In addition to the fabrication process and raw material, another focal point aims at solar concentrator. This paper shows a new and easy way to increase the solar energy efficiency. We utilize the micro- optics principle to design and fabricate a micro-lens array of the solar concentrator. With this concentrator, it can enhance the amount of focused sunlight on the solar cell so the optical absorption on the solar cell is improved. The micro-lens array concentrator (MLA- concentrator) is different from the conventional concentrator. The MLA-concentrator does not need any electric equipment to follow the sunlight (sun tracker is not required), and it is easy to manufacture. The size is smaller than conventional concentrator, especially. The MLA-concentrator can decrease the reflection of light at oblique angles and increases the second reflection at the interface between concentrator and solar cell, which makes the sunlight uniform. This new-type MLA- concentrator is fabricated by using LIGA-like process, and then it is integrated to the solar cell for electricity generation. Most important, this kind of structure can be combined with all kinds of solar cell. Figure-1. Individual secondary optics requires multiple PV cells (a). Each lens concentrate on individual secondary optics (b) Replace the secondary optics by waveguide. Arrows indicate PV cell locations. [4]. However, integrating hundreds of small PV cells all aligned to their respective optics leads to large-scale connectivity and cost concerns. A planer concentrator was investigated by replacing the secondary optics and their associated cell with a single waveguide connected to a shared PV cell [4]. In this paper, we investigate an alternative approach for planar concentration by replacing multiple nonimaging secondary optics and their associated PV cells with small rectangular slaps of PV silicon cell (see Figure-2) to reduce the number of mounting, alignment and electrical connection cost.