Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Feasibility and performance investigation of a new smart system integrating planar/tubular thermoelectric generators with solar flat plate collector A. Faddouli a,b, ⁎ , H. Labrim b , S. Fadili a , B. Hartiti a , A. Habchi a,b , M. Ertugrul c , B. Cavusoglu c , E. Ntsoenzok d a ERDyS laboratory, MEEM & DD Group, Hassan II University of Casablanca, FSTM BP 146, Mohammedia 20650, Morocco b Materials Science Unit/DERS/CNESTEN (National Centre for Energy, Sciences and Nuclear Techniques), Rabat, Morocco c Engineering Faculty, Ataturk University, 25240 Erzurum, Turkey d CEMHTI-CNRS, Site Cyclotron 3A, rue de la Férollerie, 45071 Orléans, France ARTICLE INFO Keywords: Solar water heater Planar/tubular thermoelectric modules Hybrid system Heat transfer Power generation Efficiency Simulation ABSTRACT A model of a tri-generation unit consisting of solar water heater collector, integrated with tubular and planar thermoelectric generators (TEGs) is presented. In order to optimize and obtain the effects of solar irradiance and solar concentration on the performance of system, a set of functions were coded in the MATLAB software. Twelve nonlinear algebraic equations were derived for the mathematical model and solved via the Finite Difference Method. The thermal and electrical efficiencies, the electrical characteristics of the thermoelectric, the thermal and electrical power of the hybrid device were analyzed in this study. The results have reflected some im- provements on the thermal efficiency by placing tubular TEG inside the lateral area of the absorber tube and planar TEG between the absorber and cooler plates. In order to validate the results of the mathematical model, each device studied separately to evaluate the obtained results, which are in good agreement with the results in the literature. Furthermore, the use of a concentrator shows the significant improvements in model tempera- tures, especially the working fluid that exceeds 100 °C, for which a developed program is established to control the flow rate in order to keep the temperature at 60 °C. This approach shows an excellent effect on the storage operation. Therefore, for a concentration of 20 suns, the thermal efficiency reached to 86.5% with benefit of electrical power about 161.68 Watts and quantity of hot water up to 1345 L/day, which is very promising for future solar thermal/electrical developments. 1. Introduction Renewable energy, and solar energy technologies are getting more attraction all around world. The applications of solar energy are mainly divided into photovoltaics and solar thermal energy. Power generation is ensured in photovoltaic (PV) cells by directly generating power from solar radiation. D.N. Kossyvakis et al, sees that a large proportion of solar energy is converted to waste heat in a photovoltaic (PV) cell, due to thermalization of excited, high energy electrons and absorption of low energy photons, raising the temperature of the photovoltaic cell, which leads to considerable power losses and restricts the efficiency typically to 30% or less [1]. Therefore, there has been considerable interest in coupling PV cells with a number of cooling systems techni- ques [2,3]. For example, photovoltaic/thermal (PV/T) association use heat losses effectively to reduce PV temperature, which results in high efficiency. S. Dubey, established a numerical model and applied it for PV/T, which revealed that there is a significant increase in the in- stantaneous efficiency from 33% to 64% [4]. Solar thermal energy, such as the solar water heating (SWH) system can heat water by converting the solar energy into thermal energy. Cao et al. show that a solar col- lector of 4 m 2 can satisfy the domestic hot water demand in many places worldwide. As hot water is a kind of necessity in life, the SWH gradually becomes a common household appliance because of the primary energy saving [5]. There are many strategies for coupling solar energy devices. Solar thermoelectric generators (TEGs) combined with solar collectors have been the research focus of thermoelectric technology in recent years. The TEGs are able to convert heat to electricity directly by the Seebeck effect, which has clean and quiet nature, no noise, no moving parts, pollution-free and are thus an interesting method of generating electrical power from solar energy. Recently, the research focus in the area of thermoelectricity has been geared toward thermoelectric ma- terials and forms. Having higher Seebeck coefficient, higher electrical https://doi.org/10.1016/j.enconman.2019.111980 Received 2 May 2019; Received in revised form 20 August 2019; Accepted 21 August 2019 ⁎ Corresponding authors at: ERDyS laboratory, MEEM & DD Group, Hassan II University of Casablanca, FSTM BP 146, Mohammedia 20650, Morocco. E-mail addresses: alifaddouli12@gmail.com (A. Faddouli), labrim@cnesten.org.ma (H. Labrim). Energy Conversion and Management 199 (2019) 111980 Available online 05 September 2019 0196-8904/ © 2019 Elsevier Ltd. All rights reserved. T