A comprehensive review of Uniform Solar Illumination at Low Concentration Photovoltaic (LCPV) Systems Yasaman Amanlou a , Teymour Tavakoli Hashjin a,n , Barat Ghobadian a , G. Najaﬁ a,nn , R. Mamat b a Biosystems Engineering Department, Tarbiat Modares University, Tehran, Iran b Faculty of Mechanical Engineering/Automotive Engineering Centre, Universiti Malaysia Pahang, Pekan, Pahang, Malaysia article info Article history: Received 18 January 2015 Received in revised form 10 January 2016 Accepted 8 March 2016 Keywords: Reﬂective concentrator Optical simulation Electrical performance Conventional solar cell Low Concentration Photovoltaic (LCPV) System abstract Conventional high performance silicon solar cells have a potential to generate more electricity by using low concentrating reﬂectors. Static solar concentrators reduce the cost of photovoltaic systems for given electrical power demand. However, non-uniform illumination on the conventional rectangular photo- voltaic panel causes ohmic drops, mainly due to the cell that operates locally at higher irradiance. In this research study a comprehensive review has been carried out regarding Uniform Solar Illumination at Low Concentration Photovoltaic (LCPV) Systems. Another objective of the present study is therefore, calculating the pattern of sun incident at low concentration ratios for reﬂective troughs (V-type, cylindrical and compound parabolic concentrators) and linear Fresnel reﬂectors. The geometrical para- meters of these concentrators were studied to obtain uniform illumination on the common rectangular photovoltaic panels. The designed concentrator with most uniform ﬂux distribution, high concentration ratio and low requirement of mirror was fabricated and tested at ambient conditions. The optical simulation output of different concentrators illustrated the linear Fresnel reﬂector had uniform irra- diance on the photovoltaic panel with standard deviation less than 30% of total income radiation. The experimental results showed that the linear Fresnel reﬂector has the potential to harvest more energy when using standard silicon solar cells in a basic concentration conﬁguration. Finally thermal, electrical and total performances of a photovoltaic/thermal ﬂat collector were measured with and without con- centrator. Using the concentrator improved thermal and overall efﬁciency by 16% and 17.5% respectively. The maximum overall efﬁciency for PVT collector with concentrator and without concentrator was 91% and 78% respectively. & 2016 Elsevier Ltd. All rights reserved. Contents 1. Introduction ....................................................................................................... 1431 2. Optical characteristic ................................................................................................ 1431 2.1. Concentration ratio ........................................................................................... 1431 2.2. Uniformity deﬁnition.......................................................................................... 1431 3. Type of optics ..................................................................................................... 1432 3.1. Flat concentrators or V-trough .................................................................................. 1432 3.2. Parabolic concentrator ......................................................................................... 1433 3.3. Cylindrical troughs ........................................................................................... 1433 3.4. Linear Fresnel reﬂectors ....................................................................................... 1434 4. Analysis different types of concentrators ................................................................................ 1434 4.1. Flat concentrators ............................................................................................ 1434 4.2. Parabolic concentrator ......................................................................................... 1435 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews http://dx.doi.org/10.1016/j.rser.2016.03.032 1364-0321/& 2016 Elsevier Ltd. All rights reserved. n Corresponding author. Tel.: þ0098 21 48292318; fax: þ98 21 48292200. nn Corresponding author. Tel.: þ98 21 48292322; fax: þ98 21 48292200. E-mail addresses: ttavakolh@yahoo.com (T.T. Hashjin), g.najaﬁ@modares.ac.ir (G. Najaﬁ). Renewable and Sustainable Energy Reviews 60 (2016) 1430–1441