Research Paper Microclimate and crop performance in a tunnel greenhouse shaded by organic photovoltaic modules e Comparison with conventional shaded and unshaded tunnels Maayan Friman-Peretz a,b , Shay Ozer a , Farhad Geoola a , Esther Magadley c , Ibrahim Yehia c , Asher Levi a , Roman Brikman a , Shelly Gantz d , Avi Levy b , Murat Kacira e , Meir Teitel a,* a Institute of Agricultural Engineering, Agricultural Research Organization, The Volcani Center, HaMaccabim Road 68, P.O. Box 15159, Rishon LeZion 7528809, Israel b Department of Mechanical Engineering, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 81405, Israel c Triangle Research and Development Center, P.O. Box 2167, Kfar-Qari 30075, Israel d Agricultural Extension Service of Israel - Shaham, Ministry of Agriculture, HaMaccabim Road 68, Rishon LeZion, P.O.Box 30, Beit Dagan 50200, Israel e Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, USA article info Article history: Received 18 April 2020 Received in revised form 24 May 2020 Accepted 10 June 2020 Keywords: Organic photovoltaic Greenhouse Shading Radiation Tomato The use of flexible and semi-transparent organic photovoltaic (OPV) modules as shading elements in a greenhouse tunnel with a tomato crop is presented. Experiments were performed in two similar greenhouse tunnels, covered by diffuse polyethylene sheet, during two summer growing seasons. In 2018, one tunnel was shaded using OPV modules (covering 37% of the roof area and resulting in 23% shading) and the second tunnel served as a control. In 2019, a 25% black shading screen was added to the control tunnel. The microclimate, yield, and physiological parameters were examined in the two tunnels. Results show that at noon (11:00 to 13:00), there was no significant difference in the mean seasonal (JuneeSeptember 2018, MayeAugust 2019) air temperature and humidity between the tunnels. In 2018, the tunnels differed in terms of the spatial radiation transmittance and leaf temperature. The average radiation level along the OPV tunnel centreline was much lower, and the radiation distribution was less homogeneous than in the control. In 2019, with similar shading percentages in the tunnels, similar average radiation levels were observed. The leaf temperature in the OPV was lower than in the control in 2018 and varied from higher to lower in 2019. The leaf area index (LAI), cumulative yield, and average fruit mass were higher in the OPV than in the control in 2018, and similar in 2019. The average value of the maximum power output of three OPV modules increased roughly linearly with irradiance. © 2020 IAgrE. Published by Elsevier Ltd. All rights reserved. * Corresponding author. E-mail address: grteitel@agri.gov.il (M. Teitel). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/issn/15375110 biosystems engineering 197 (2020) 12 e31 https://doi.org/10.1016/j.biosystemseng.2020.06.007 1537-5110/© 2020 IAgrE. Published by Elsevier Ltd. All rights reserved.