Light Environment Analysis and Production of Red Leaf Lettuce in Greenhouses with Flexible Solar Cells

Eunjeong Lim; Gyeong-Su Seo; Inha Hwang; Il-Kyung Shin; Myung-Min Oh

doi:10.7235/HORT.20240019

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2024 Vol.42, Issue 2 Preview Page Next Page

Research Article

Light Environment Analysis and Production of Red Leaf Lettuce in Greenhouses with Flexible Solar Cells 유연기판 태양전지가 설치된 온실 내의 광분포 분석 및 적상추의 생산

30 April 2024. pp. 225-233

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Abstract

Recently, agrivoltaic systems, which utilize a solar-sharing conception by having solar cells installed on top of the cultivation area, using the extra solar light for photovoltaics, have been attracting attention. However, most applications are reported in open-field conditions, and some issues have been raised about the installation of these structures. Accordingly, we conducted a cultivation experiment in which an agrivoltaic system was applied to protected horticulture with flexible solar cells. Red leaf lettuce was used in the experiment and was cultivated in three single greenhouses with the system installed either on one side of the greenhouse ceiling, denoted as photovoltaic I, or on both sides denoted as photovoltaic Ⅱ. The control system used no agrivoltaic system. A ray-tracing simulation was also conducted to determine the light distribution of the total greenhouse floor area and daily difference according to solar altitude changes. It was found that the monthly amounts of energy generated in the greenhouses were 156.85 and 323.34 kWh for photovoltaic Ⅰ and photovoltaic Ⅱ, respectively. Due to the area shaded from light by the solar cells, daily light integral (DLI) values were 86% of the control for photovoltaic Ⅰ and 71% for photovoltaic Ⅱ. In the results of the ray-tracing simulation under identical conditions, the root mean square error between the calculated DLI and the measured DLI was 14.8 µmol·m^-2·day^-1. The shoot fresh weight, leaf area, SPAD and anthocyanin content of red leaf lettuces showed no significant differences according to the treatment. Through this study, it was confirmed that greenhouses with flexible solar cells can be applied for the production of leafy vegetable such as lettuce with low light saturation points.

Keywords

agrivoltaic system

daily light integral (DLI)

light distribution

ray-tracing simulation

solar sharing

최근 작물 재배면적 상부에 태양전지를 설치하여 잉여의 태양광을 에너지 발전에 사용하는 solar sharing 개념의 영농형 태양광발전 시스템이 주목을 받고 있다. 하지만 대부분의 적용은 노지재배이며 태양전지 설치를 위한 구조물에 따른 문제점이 대두되면서 본 연구에서는 유연기판 태양전지를 활용하여 영농형 태양광발전 시스템을 시설원예로 적용하기 위해 재배실험을 수행하였다. 실험에는 적상추가 사용되었으며 태양전지가 온실 천장의 한 면에만 설치된 태양광Ⅰ, 두 면 모두에 설치된 태양광Ⅱ 그리고 설치되지 않은 대조구의 세 단동 아치형 비닐하우스에서 재배되었다. 또한 온실 내부 면적 전체의 광량 및 태양고도 변화에 따른 일중 변화를 위해 시뮬레이션상에 온실 조건을 구현하여 광추적 시뮬레이션을 수행하였다. 두 처리구 온실에서의 월별 발전량은 태양광Ⅰ, 태양광Ⅱ에서 각각 평균 156.85kWh, 323.34kWh였다. 태양전지에 의한 차광으로 인해 온실 내부에서 측정된 DLI값은 대조구 대비 태양광Ⅰ에서 86%, 태양광Ⅱ는 71%를 보였으며, 동일한 조건에서 광추적 시뮬레이션 결과 DLI값은 측정값과 14.8µmol·m^-2·day^-1의 평균제곱근오차를 기록했다. 재배 결과 지상부생체중, 엽면적, SPAD, 안토시아닌 함량과 같은 전 항목에서 처리에 따른 통계적 유의성을 보이지는 않았다. 이를 통해 유연기판 태양전지가 설치된 온실에서의 상추과 같은 광요구도가 낮은 엽채류 생산이 가능함을 확인하였다.

키워드

영농형태양광발전

일적산광량

광분포

광추적시뮬레이션

솔라쉐어링

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Information

Publisher :KOREAN SOCIETY FOR HORTICULTURAL SCIENCE
Publisher(Ko) :원예과학기술지
Journal Title :Horticultural Science and Technology
Journal Title(Ko) :원예과학기술지
Volume : 42
No :2
Pages :225-233
Received Date : 2023-03-13
Revised Date : 2023-06-28
Accepted Date : 2023-07-18
DOI :https://doi.org/10.7235/HORT.20240019

Horticultural Science and Technology ISSN:1226-8763(Print) 2465-8588(Online) 원예과학기술지

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