Design, simulation, and experimental evaluation of an agrivoltaic greenhouse in Turkey

Agrivoltaic greenhouses represent a promising approach for simultaneously achieving renewable energy production and agricultural productivity. Despite significant research, gaps remain concerning the practical integration of bifacial photovoltaic (PV) systems into greenhouse structures, particularly regarding detailed pre-design simulations combined with experimental validation under Mediterranean climatic conditions. This study addresses these gaps by designing, simulating, constructing, and experimentally validating a bifacial PV-integrated greenhouse in Ankara, Turkey. Advanced ray-tracing simulations with bifacial_radiance software evaluated multiple design parameters, including roof coverage ratios, PV layout patterns, greenhouse shapes, and orientations, with the aim of optimizing light distribution and photovoltaic yield. A checkerboard PV pattern covering 33 % of the greenhouse roof with an east-west orientation was identified as optimal for uniform light distribution. Experimental evaluations conducted on tomato and bell pepper crops over two growing seasons (2022-2023) showed yield reductions of 26-32 % in 2022, decreasing significantly to 15-18 % in 2023 due to improved shading management. Energy simulations predicted an annual specific PV yield of approximately 1211 kWh/kWp, closely aligned with operational data (1264 kWh/kWp) despite partial system use owing to grid limitations. The PV system successfully covered nearly all greenhouse energy demands except for heating. The findings highlight the delicate balance required between PV energy generation and agricultural yield and underscore the importance of comprehensive economic assessments to quantify the environmental and financial benefits of agrivoltaic systems.