Energy performance assessment of photovoltaic greenhouses in summer based on coupled optical-electrical-thermal models and plant growth requirements

https://doi.org/10.1016/j.enconman.2023.117086

Highlights

• •Energy assessment of greenhouse is presented based on plant growth requirements.

  
  

• •Mean net photosynthetic rate increases and then drops with coverage area raised.

  
  

• •Daily cooling load reduces by 0.45–1.02 kWh when coverage ratio increases by 10%.

  
  

• •Photovoltaic generation rises by 1.7–3.19 kWh/d when coverage ratio rises 10%.

  
  

• •Coefficient of performance increases and then decrease with coverage areas rising.

• Abstract

• Photovoltaic (PV) greenhouses are widely used to regulate internal irradiance and air temperature to create optimal climatic conditions for plant growth. Therefore, comprehensive multidomain energy models of PV greenhouses are more likely needed to improve the system performance. However, few studies investigate optical-electrical-thermal characteristics and PV greenhouse evaluation indicators based on crop growth requirements. The aim of this work is to develop coupled optical-electrical-thermal models to assess the energy performance of the PV greenhouse with different PV roof coverage ratios during the summer months. In addition, the models of photosynthetically active radiation (PAR) and net photosynthetic rate (PN) are presented based on the irradiance and temperature of the PV greenhouse to evaluate the dynamic response of crops to interior climate conditions. The models are validated with experiments on the PV greenhouse in Kunming, with a total area of 26.25 m2. The electricity supply and demand systems include PV modules (3.285 kWp), a battery bank (24 kWh), an air–water heat pump (AWHP), and spray combined with fan cooling. Two cooling scenarios are analysed and compared by varying the PV module coverage ratio. Scenario 1 (S.1) is AWHP cooling, and scenario 2 (S.2) is spray combined with fan cooling. The optimum interior temperature and PAR of the PV greenhouse are 22 °C and 300 μmol·m−2·s−1, respectively. The simulations indicate that if the proportion of the PV layout on the greenhouse roof is greater than 20%, the year-round PAR inside the greenhouse will be below the threshold value of 550 μmol·m−2·s−1 at which the strawberry PN is saturated. For every 10% increase in PV roof coverage, the interior air temperature decreases by 0.02–0.56 °C corresponding to a daily cooling load reduction of 0.45–1.02 kWh/d, while the PV generation increases by 1.7–3.19 kWh/d and the maximum electricity consumption of S.1 and S.2 drops by 0.66 kWh/d and 0.52 kWh/d, respectively. Moreover, the high self-consumption-sufficiency balance (SCSB) values show that the PV and battery sizes are 2.22–2.78 kWp (40–50% coverage) and 15.72–15.75 kWh for S.1, and those in S.2 are 1.11–1.67 kWp (10–30% coverage) and 0.66–3.22 kWh. The coefficient of performance (COP) of the system reaches a maximum of 0.45–1.12 at 40% coverage in S.1 and 1.88–3.01 at 10–30% coverage in S.2. When the PV module coverage is 40% in S.1, the levelized costs of electricity (LCOE) and levelized costs of cooling (LCOC) are the lowest at 0.0760USD/kWhel and 0.0693USD/kWhc. Similarly, the lowest LCOE and LCOC of S.2 are 0.0306USD/kWhel and 0.0210USD/kWhc, as the PV module coverage is 30%. The study will be beneficial for applying photovoltaic modules, battery banks, and cooling technologies in the greenhouse, especially considering the dynamic crop response to internal climates and the energy performance assessment.

马逊教授简介

马逊

农业电气化与自动化专业，副教授，硕士生导师

E-mail：maxun@ynnu.edu.cn

学术任职及兼职

1. 云南省高校太阳能供热与制冷技术重点实验室，副主任

2. 云南电机工程学会理论电工专委会，委员

3. 云南省土木建筑学会电气专业委员会，理事

主要招生专业：

1. 农业电气化与自动化

2. 能源动力

主要研究方向：

1.光伏系统“网-源-荷-储”优化调控

2. 光伏温室系统研究

3. 晶体硅光伏组件衰退特性研究

4. 晶体硅太阳电池制备 

学历及研究简历：

1.1998年9月-2002年6月，华中科技大学，本科生，光电子工程专业

2.2002年9月-2005年6月，云南师范大学，硕士研究生，农业生物环境与能源工程专业

3.2006年9月-2011年6月，中国农业大学，博士研究生，农业生物环境与能源工程专业

4.2013年1月-2017年4月，云南师范大学，博士后流动站，农业工程专业

近三年代表论文和著作：

1.  Ma X*（马逊）, Li M, Peng Y. Development of thermos-electrical loss model for photovoltaic module with inhomogeneous temperature [J]. Energy, 2022, 248, 123542.（JCR一区） 

2.  Lu GS, Ma X*（马逊）, Li M. Performance characteristics of direct contact refrigeration system based on phase change materials and different refrigerants [J]. Applied Thermal Energy, 2022, 215, 118974. （JCR二区）

3. 周晓艳，马逊*，李明. 基于动态阻抗匹配控制下的光伏冷库性能研究[J]. 太阳能学报 ，2022，43(3):180-187. （EI期刊收录）

4. Tang Y, Ma X*（马逊）, Li M. The effect of temperature and light on strawberry production in a solar greenhouse [J]. Solar Energy, 2020, 159, 318-328. （JCR二区）

5. Du LW , Li MX, Ma X（马逊）. A Fast Positive Sequence Components Extraction Method with Noise Immunity in Unbalanced Grids [J]. IEEE TRANSACTIONS ON POWER ELECTRONICS, 2020,35(7), 6682-6685（JCR一区）

6. Ma X（马逊）, Li M, Du LW. Online extraction of physical parameters of photovoltaic modules in a building-integrated photovoltaic system [J]. Energy Conversion and Management 2019 (199) 112028. （JCR一区）

近三年主持国家级或百万以上其他项目：

1. 面向温室场景下双面发电光伏组件最大功率跟踪与有功功率备用的关键机理与协同调控研究，国家自然科学基金项目（52267020），2023.1-2026.12

2. 基于作物最佳光合效率下光伏温室系统“源-储-荷”协同机理与调控研究，国家自然科学基金项目（51867022），2019.1-2022.12

3. 2022年“智汇云南”计划-青年科学家、青年企业家Vilaythong AIRMIXAY，云南省科技厅科技重点研发计划（202203AM140016），2022.6-2023.5

4. 光伏组件PID效应与热斑效应机理研究，云南省科技厅基础研究面上项目（2017FB089），2017.6-2020.5

近三年主持的教学教改及省级以上教学质量工程 

1. 构建“双碳”背景下农业工程硕士专业协同育人基地及其运行机制研究，全国农业专业学位研究生专业指导委员会面上项目（2021-NYYB-51），2022.1-2024.12

2. 构建“双碳”背景下光伏科学课程思政建设与协同育人机制研究，云南师范大学思政课程教改项目，2022.5-2024.4

3. 研究生课程《光伏农业技术》教学改革，云南师范大学思政课程教改项目，（SZ2021-A17），2022.1-2024.12

近三年主讲课程（研究生、本科生）：

1.2006年至今：《光伏科学》，本科生课程

2.2008年至今：《光伏科学实验》，本科生课程

3. 2017年至今：《电工与电子技术》，本科生课程

4.2020年至今：《光伏农业技术》，农业工程专业硕士研究生课程

5. 2021年至今：《能源利用与节能技术》能源动力专业硕士研究生课程

参考阅读：https://solar.ynnu.edu.cn/info/1187/3110.htm