Abstract
In the Ouargla region, the desert area of Algeria, photovoltaic fields (PV) suffer from hard climate conditions with hightemperature levels. This temperature level causes a significant fall of PV cells efficiency which requires an integrated cooling system. For achieving this purpose, a thermal part based on airflow provided along a straight channel under the PV module (150 W) is added. It extracts the accumulated heat by air natural convection, then, the airflow passes through an upper glass extension (0.56 m) to reinforce the heat collection. The evaluation of the whole system performance is experimentally conducted by performing several variations of operating parameters and air channel depth. This photovoltaicthermal (PV/T) system has modeled by a set of balanced energy equations that are resolved numerically using Matlab software. The experimental results show that the increase in the channel depth causes a significant reduction of thermal efficiency and a slight effect on the electrical one. The numerical data are compared and validated by the experimental results, where the characteristic curves (efficiencies, polarization, powers, temperatures) show good concordance with experimental data. The root means square of percentage deviation (RMSD) is between 1.75% and 16.25%. For a channel depth of 10 cm, the energy and exergy efficiency reach their mean values of 58.5% and 14.7%, respectively. The glass extension of 1.6 m gives a net improvement of 5% in the overall energy efficiency.
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Abbreviations
 BIPV/T:

Buildingintegrated photovoltaic/thermal
 CPC:

Compound parabolic concentrator
 ER:

Relative error
 LCA:

Life cycle assessments
 RMSD:

Root means square deviation
 PV:

Photovoltaic
 PV/T:

Photovoltaic/thermal
 A :

Area
 A _{Ch} :

Crosssection of the channel area
 b _{ch} :

Breadth of channel
 c _{a} :

Specific heat capacity (kJ/kg K)
 G :

Solar radiation intensity (W/m^{2})
 h :

Coefficient of heat transfer
 h _{p1} :

Penalty factor
 h _{p2} :

Penalty factor
 I :

Circuit current (A)
 ṁ :

Air mass flow rate (kg/s)
 P :

Power (W)
 q _{u} :

Thermal energy (W)
 q _{exo} :

Exergy overall (W)
 T :

Temperature
 U _{b} :

Overall back loss coefficient from flowing air to ambient through the insulator (Wm^{−2} K^{−1})
 U _{T} :

Coefficient of conductive heat transfer from the solar cell to air through tedler
 U _{tT} :

Coefficient of overall heat transfer from glass to tedler through solar cell
 U _{t} :

Coefficient of overall heat transfer from the solar cell to ambient through glass
 U _{L} :

Coefficient of overall heat transfer from the solar cell to ambient through top and back surface of the insulation
 V :

Circuit voltage (V), wind speed (m/s)
 R :

Resistance (Ω)
 amb:

Ambient
 bs:

The back surface
 c:

Solar cells
 co:

Opencircuit
 el:

Electrical
 ex:

Exergy
 exp:

Experimental
 g:

Glass
 ins:

Insulator
 mpp:

Maximum power point
 O:

Overall
 Out:

Outlet
 p:

Absorber plate
 ref:

Reference conditions
 s:

Sky
 sc:

Shortcircuit
 T :

Tedler
 th:

Thermal
 α :

Absorptivity
 β _{c} :

Factor of solar packing cells
 ɛ :

Emissivity
 η :

Efficiency
 λ :

Thermal conductivity (Wm^{−}^{1} K^{−}^{1})
 μ :

Dynamic viscosity (kg m^{−1} s^{−1})
 ρ :

Density (kg/m^{3})
 τ :

Transitivity
References
 1.
Ghedamsi, R., Settou, N., Gouareh, A., Khamouli, A., Saifi, N., Recioui, B., Dokkar, B.: Modeling and forecasting energy consumption for residential buildings in Algeria using bottomup approach. J. Energy Build. 121, 309–3017 (2016)
 2.
Dokkar, B., Negrou, B., Settou, N., Imine, O., Chennouff, N., Benmhidi, A.: Optimization of PEM fuel cells for PVhydrogen power system. J. Energy Proc. 36, 798–807 (2013)
 3.
Dokkar, B., Settou, N., Chennouff, N.: Application des énergies renouvelables: Alimentation électrique d’une résidence. Éditions universitaires européennes, (2016)
 4.
Hussein, A.K., Walunj, A., Kolsi, L.: Applications of nanotechnology to enhance the performance of the direct absorption solar collectors. J. Therm. Eng. 2(1), 529–540 (2016)
 5.
YoucefAli, S., Desmons, J.Y.: Numerical and experimental study of a solar equipped with offset rectangular plate fin absorber plate. J. Renew. Energy 31, 2063–2075 (2006)
 6.
Liu, Y.D., Diaz, L.A., Suryanarayana, N.V.: Heat transfer enhancement in air heating flatplate solar collectors. Transactions of ASME. J. Sol. Energy Eng. 106, 363–385 (1984)
 7.
Zhang, H., Ma, X., You, S., Wang, Y., Zheng, X., Ye, T., Zheng, W., Wei, S.: Mathematical modeling and performance analysis of a solar air collector with slitperforated corrugated plate. J. Sol. Energy 167, 147–157 (2018)
 8.
Tiwari, A., Sodha, M.S., Chandra, A., Joshi, J.C.: Performance evaluation of photovoltaic thermal solar air collector for composite climate of India. J. Sol. Energy Mater. Solar Cells 90, 175–189 (2006)
 9.
Yang, T., Athienitis, A.K.: A review of research and developments of buildingintegrated photovoltaic/thermal (BIPV/T) systems. J. Renew. Sustain. Energy Rev. 66, 886–912 (2016)
 10.
Hussein, A.K.: Applications of nanotechnology to improve the performance of solar collectors—Recent advances and overview. Renew. Sustain. Energy Rev. 62, 767–792 (2016)
 11.
Raghuraman, P.: Analytical predictions of liquid and air photovoltaic/thermal flat plate collector performance. J. Sol. Energy Eng. 103, 291–308 (1981)
 12.
Hussein, A.K., Li, D., Kolsi, L., Kata, S., Sahoo, B.: A review of nano fluid role to improve the performance of the heat pipe solar collectors. Energy Proc. 109, 417–424 (2017)
 13.
Hosseinzadeh, M., Salari, A., Sardarabadi, M., PassandidehFard, M.: Optimization and parametric analysis of a nanofluid based photovoltaic thermal system: 3D numerical model with experimental validation. Energy Convers. Manag. 160, 93–108 (2018)
 14.
Hussein, A.K.: Applications of nanotechnology in renewable energiesA comprehensive overview and understanding. Renew. Sustain. Energy Rev. 42, 460–476 (2015)
 15.
Bergene, T., Lovvik, O.M.: Model calculations on a flatplate solar heat collector with integrated solar cells. J. Sol. Energy 55, 453–462 (1995)
 16.
Touafek, K., Haddadi, M., Malek, A.: Design and modeling of a photovoltaic thermal collector for domestic air heating. J. Energy Build. 59, 21–28 (2013)
 17.
Sarhaddi, F., Farahat, H., Bahzadmehr, A., Adeli, M.: An improved thermal and electrical model for a solar photovoltaic thermal (PV/T) air collector. J. Appl. Energy 87, 2328–2339 (2010)
 18.
Akpinar, E.K., Kocyigit, F.: Energy and exergy analysis of a new flatplate solar air heater having different obstacles on absorber plates. J. Appl. Energy 87, 3438–3450 (2010)
 19.
Kim, J.H., Park, S.H., Kim, J.T.: Experimental performance of a Photovoltaicthermal air collector. J. Energy Proc. 48, 888–894 (2014)
 20.
Joshi, A.S., Tiwari, A.: Energy and exergy efficiencies of a hybrid photovoltaicthermal (PV/T) air collector. J. Renew. Energy 32, 2223–2241 (2007)
 21.
Rajoria, S.C., Agrawal, S., Tiwari, G.N., Chaursia, G.S.: Exergetic and enviroeconomic analysis of semitransparent PVT array based on optimum air flow configuration and its comparative study. J. Sol. Energy 122, 1138–1145 (2015)
 22.
Tonui, J.K., Tripanagnostopoulos, Y.: Performance improvement of PV/T solar collectors with natural air flow operation. J. Sol. Energy 82, 1–12 (2008)
 23.
Moshfegh, B., Sandberg, M.: Investigation of fluid flow and heat transfer in a vertical channel heated from one side by PV elements. Part INumerical study. Renew. Energy. 8, 248–253 (1996)
 24.
Sopian, K., Liu, H., Kakac, S., Veziroglu, T.N.: Performance of a double pass photovoltaic thermal solar collector suitable for solar drying systems. J. Energy Convers. Manag. 41, 353–365 (2000)
 25.
Agrawal, S., Tiwari, G.N.: Overall energy, exergy and carbon credit analysis by different type of hybrid photovoltaic thermal air collectors. J. Energy Conver. Manage. 65, 628–636 (2013)
 26.
Shahsavar, A., Ameri, M.: Experimental investigation and modeling of a direct coupled PV/T air collector. J. Sol. Energy 84, 1938–1958 (2010)
 27.
Tiwari, S., Tiwari, G.N.: Energy and exergy analysis of a mixedmode greenhousetype solar dryer, integrated with partially covered NPVT air collector. J. Energy 128, 183–195 (2017)
 28.
Daghigh, R., Shafieian, A.: An experimental study of a heat pipe evacuated tube solar dryer with heat recovery system. J. Renew. Energy 96, 872–880 (2016)
 29.
Kasaeian, A., Khanjari, Y., Golzari, S., Mahian, O., Wongwises, S.: Effects of forced convection on the performance of a photovoltaic thermal system: an experimental study. J. Exp. Therm. Fluid Sci. 85, 13–21 (2017)
 30.
Huide, F., Xuxin, Z., Lei, M., Tao, Z., Qixing, W., Hongyuan, S.: A comparative study on three types of solar utilization technologies for buildings: photovoltaic, solar thermal and hybrid photovoltaic/thermal systems. Energy Convers. Manag. 140, 1–13 (2017)
 31.
Omer, K.A., Zala, A.M.: Experimental investigation of PV/thermal collector with theoretical analysis. Renew. Energy Focus 27, 67–77 (2018)
 32.
Elsafi, A.M., Gandhidasan, P.: Comparative study of doublepass flat and compound parabolic concentrated photovoltaicthermal systems with and without fins. J. Energy Convers. Manag. 98, 59–68 (2015)
 33.
Tiwari, G.N., Mishra, A.K., Meraj, Md, Ahmad, A., Khan, M.E.: Effect of shape of condensing cover on energy and exergy analysis of a PVTCPC active solar distillation system. J. Sol. Energy 205, 113–125 (2020)
 34.
Wu, S.Y., Wang, T., Xiao, L., Shen, Z.G.: Effect of cooling channel position on heat transfer characteristics and thermoelectric performance of aircooled PV/T system. Sol. Energy 180, 489–500 (2019)
 35.
Özakin, A.N., Kaya, F.: Effect on the exergy of the PVT system of fins added to an aircooled channel: a study on temperature and air velocity with ANSYS Fluent. J. Sol. Energy 184, 561–569 (2019)
 36.
Good, C.: Environmental impact assessments of hybrid photovoltaicthermal (PV/T) systems: a review. Renew. Sustain. Energy Rev. 55, 234–239 (2016)
 37.
Ndiho, A., Wuitcha, K.N., Samah, H.A., Banna, M.: Numerical study of natural convection through a photovoltaicthermal (PV/T) building solar chimney suitable for natural cooling. Int. J. Sci. Technol. Res. 3, 148–155 (2014)
 38.
Boumaaraf, B., Boumaaraf, H., Slimani, M.E., Kebir, S.T., Aitcheikha, M.S., Touafek, K.: Performance evaluation of a locally modified PV module to a PV/Tsolar collector under climatic conditions of semiarid region. Math. Comput. Simul. 167, 135–154 (2020)
 39.
Delisle, V., Kummert, M.A.: Novel approach to compare buildingintegrated photovoltaics/thermal air collectors to sidebyside PV modules and solar thermal collectors. J. Sol. Energy 100, 50–65 (2014)
 40.
Su, D., Jia, Y., Huang, X., Alva, G., Tang, Y., Fang, G., : Dynamic performance analysis of photovoltaicthermal solar collector with dual channels for different fluids. J. Energy Convers. Manag. 120, 13–24 (2016)
 41.
Li, D., Li, Z., Zheng, Y., Liu, C., Hussein, A.K., Liu, X.: Thermal performance of a PCMfilled doubleglazing unit with different thermo physical parameters of PCM. Sol. Energy 133, 207–220 (2016)
 42.
Duffie, J.A., Beckman, W.A.: Solar engineering of thermal processes, 2nd edn. Wiley, New York (1991)
 43.
Joshi, A.S., Dincer, I., Reddy, B.V.: Thermodynamic assessment of photovoltaic systems. J. Sol. Energy 83(8), 1139–1149 (2009)
 44.
Sellami, R., Amirat, M., Mahrane, A., Slimani, M.E.A., Arbane, A., Chekrouni, R.: Experimental and numerical study of a PV/Thermal collector equipped with a PVassisted air circulation system: configuration suitable for building integration. Energy Build. 190, 216–234 (2019)
 45.
Saeedi, F., Sarhaddi, F., Behzadmehr, A.: Optimization of a PV/T (photovoltaic/thermal) active solar still. J. Energy. 87, 142–152 (2015)
 46.
Rejeb, O., Sardarabadi, M., Ménézo, C., PassandidehFard, M.: Numerical and model validation of uncovered nanofluid sheet and tube type photovoltaic thermal solar system. J. Energy Convers. Manag. 110, 367–377 (2016)
 47.
Orioli, A., Di Gangi, A.: A procedure to calculate the fiveparameter model of crystalline silicon photovoltaic modules on the basis of the tabular performance data. J. Appl. Energy 102, 1160–1177 (2012)
 48.
Soltani, S., Kasaeian, A., Sarrafha, H.: An experimental investigation of a hybrid photovoltaic/thermoelectric system with nanofluid application. Sol. Energy 155, 1033–1043 (2017)
 49.
Amori, K.E., AbdAlRaheem, M.A.: Field study of various air based photovoltaic/thermal hybrid solar collectors. J. Renew. Energy 63, 402–414 (2014)
 50.
Chow, T.T.: A review on photovoltaic/thermal hybrid solar technology. J. Appl. Energy 87(2), 365–379 (2010)
 51.
Jarimi, H., Abu Bakar, M.N., Othman, M., Hj Din, M.: Bifluid photovoltaic/thermal (PV/T) solar collector: experimental validation of a 2D theoretical model. Renew. Energy 85, 1052–1067 (2016)
 52.
Slimani, M.E.A., Amirat, M., Kurucz, I., Bahria, S., Hamidat, A., Chaouch, W.: A detailed thermalelectrical model of three photovoltaic/thermal (PV/T) hybrid air collectors and photovoltaic (PV) module: comparative study under Algiers climatic conditions. J. Energy Convers. Manag. 133, 485–476 (2017)
 53.
Aoues, K., Moummi, N., Zellouf, M., Benchabane, A.: Thermal performance improvement of solar air flat plate collector: a theoretical analysis and an experimental study in Biskra, Algeria. Int. J. Ambient Energy 32, 95–102 (2011)
 54.
Amori, K.E., Hussein, M., AlNajjar, T.: Analysis of thermal and electrical performance of a hybrid (PV/T) air based solar collector for Iraq. J. Appl. Energy 98, 384–395 (2012)
 55.
Agrawal, B., Tiwari, G.N.: Life cycle cost assessment of building integrated photovoltaic thermal (BIPVT) systems. Energy Build. 42(9), 1472–1481 (2010)
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Appendix A
Appendix A
The following formulations are used in thermal mathematical model of the proposed PV/T collector.
The expressions for (A, B, C, D, E, F, K, S, R, W, N and Z) used in Eqs. (30), (31), (32), (33) are:
where h_{w} is the heat coefficient due to wind, h_{c,p–in} is the thermal insulator.
where h_{v,air–p} is the Coefficient of convective heat transfer from the plate to air duct, h_{r,p–g} is the aluminum plate to the glass coefficient.
where h_{v,air–g} is the Coefficient of convective heat transfer from the glass to air duct, h_{r,s–g} is the sky to the glass coefficient.
where b_{ch} is the width of channel.
where \(\dot{m}\) is the mass flow rate, C_{a} is the specific heat capacity of air.
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Khenfer, N., Dokkar, B. & Messaoudi, M.T. Overall efficiency improvement of photovoltaicthermal air collector: numerical and experimental investigation in the desert climate of Ouargla region. Int J Energy Environ Eng (2020). https://doi.org/10.1007/s40095020003531
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Keywords
 PV/T system
 Airflow
 Plate absorber
 Natural convection
 Overall efficiency