Analysis of Microclimatic Conditions, Crop Growth and Power Generation in Agrivoltaic System

A Case for the Agrivoltaic System of the National Chiayi University in Taiwan

Abstract

The understanding of the impacts of shading on crop growth plays a vital role in promoting agrivoltaics. This study explores how the shading of photovoltaic panels affects the growth of corn, upland rice, lettuce, sweet potato and bok choy, and evaluates the performance of photovoltaics taking into account crop growth and power generation. Two static configurations were used with full-density and half-density layouts of photovoltaic panels of shading rates of 86% and 43%, respectively. Among the five crops evaluated and harvested, the dry weights of corn and upland rice per plant were less affected by shading than lettuce, sweet potato and bok choy. This suggests the potential for integrating corn and upland rice into agrivoltaic systems. Upland rice, lettuce, sweet potato and bok choy are all C3 plants that are known to require about half of full sunlight for saturation of photosynthesis under the subtropical spring conditions of this study. The growth of these C3 crops is severely affected under a shading rate of 86% while that under a shading rate of 43% reaches at least 68% yield. Thus, an upper shading limit of 40% should be considered for growing C3 crops in an agrivoltaic system. The growth of corn, a C4 crop, under 43% shading reached 92% of the control, indicating its potential as an agrivoltaic crop. The growth performance of these crops under a shading rate of 86% was better than expected, suggesting that the small system allowed for radiation from sides. The distance between solar panels should be considered as a factor influencing crop growth in addition to shading rate.