Shading and Irradiance

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Agrivoltaic system: Estimation of photosynthetic photon flux density under solar panels based on solar irradiation data using all-climate solar spectrum model

This study focused on the photosynthetic photon flux density and employed an all-climate solar spectrum model to calculate the photosynthetic photon flux density accurately on farmland partially shaded by solar panels and supporting tubes. The researchers also described an algorithm for estimating the photosynthetic photon flux density values under solar panels, which were then validated using photosynthetic photon flux density sensors. The calculation formula enables farmers to evaluate the economic efficiency of a system before introducing it.
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Microclimate under agrivoltaic systems: Is crop growth rate affected in partial shade of solar panels?

Researchers in this study monitored soil and air temperature, humidity, wind speed, and incident radiations at a full sun site, as well as at two agrivoltaic systems with different densities of photovoltaic panels. They recorded the findings during three seasons (winter, spring, and summer) with both short cycle crops (lettuce and cucumber) and a long cycle crop (durum wheat). The researchers concluded that little adaptations in cropping practices should be required to switch from an open cropping to an agrivoltaic cropping system and attention should mostly be focused on mitigating light reduction and on selection of plants with a maximal radiation use efficiency in these conditions of fluctuating shade.
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Simulated solar panels create altered microhabitats in desert landforms

Researchers in this study used experimental panels to simulate the effects of solar development on microhabitats and annual plant communities present on gravelly bajada and caliche pan habitat, two common habitat types in California's Mojave Desert. They evaluated soils and microclimatic conditions and measured community response under panels and in the open for seven years. The study's results demonstrate that the ecological consequences of solar development can vary over space and time and suggest that a nuanced approach will be needed to predict impacts across desert landforms differing in physical characteristics.
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The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

This research addresses the concern that photovoltaic systems create a "heat island" effect. Researchers examined the heat island effect with experiments spanning three biomes and found that temperatures over a photovoltaic plant are regularly 3–4°C warmer than wildlands at night, a direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures.
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Spatial Distribution Model of Solar Radiation for Agrivoltaic Land Use in Fixed PV Plants

When installing photovoltaic panels on agricultural land, one of the most important aspects to consider are the effects of the shadows of the panels on the ground. This study presents a valid methodology to estimate the distribution of solar irradiance in agrivoltaic installations as a function of the photovoltaic installation geometry and the levels of diffuse and direct solar irradiance incident on the crop land.
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Photosynthetically Active Radiation Decomposition Models for Agrivoltaic Systems Applications

Decomposition models of solar irradiance estimate the magnitude of diffuse horizontal irradiance from global horizontal irradiance. These two radiation components are well-known to be essential for the prediction of solar photovoltaic systems performance. In open-field agrivoltaic systems, that is the dual use of land for both agricultural activities and solar power conversion, cultivated crops receive an unequal amount of direct, diffuse and reflected photosynthetically active radiation (PAR) depending on the area they are growing due to the non-homogenously shadings caused by the solar panels installed (above the crops or vertically mounted). It is known that PAR is more efficient for canopy photosynthesis under conditions of diffuse PAR than direct PAR per unit of total PAR. For this reason, it is fundamental to estimate the diffuse PAR component in agrivoltaic systems studies to properly predict the crop yield.
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GROUND IRRADIANCE MODELLING: OF KEY IMPORTANCE FOR DESIGNING NATURE INCLUSIVE SOLAR PARKS AND AGRIVOLTAICS SYSTEMS

Solar electricity from solar parks in rural areas are cost effective and can be deployed fast therefore play an important role in the energy transition. The optimal design of a solar park is largely affected by income scheme, electricity transport capacity, and land lease costs. Important design parameters for utility-scale solar parks that may affect landscape, biodiversity, and soil quality are ground coverage ratio, size, and tilt of the PV tables. Particularly, low tilt PV at high coverage reduces the amount of sunlight on the ground strongly and leads to deterioration of the soil quality over the typical 25-year lifetime. In contrast, vertical PV or an agri-PV design fairly high above the ground leads to more and homogeneous ground irradiance; these designs are favored for pastures and croplands. In general, the amount and distribution of ground irradiance and precipitation will strongly affect which crops can grow below and between the PV tables and whether this supports the associated food chain. As agrivoltaics is the direct competition between photosynthesis and photovoltaics. Understanding when, where and how much light reaches the ground is key to relate the agri-PV solar park design to the expected agricultural and electricity yields.
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Solar park microclimate and vegetation management effects on grassland carbon cycling

Increasing energy demands and the drive towards low carbon (C) energy sources has prompted a rapid increase in ground-mounted solar parks across the world. This represents a significant global land use change with implications for the hosting ecosystems that are poorly understood. In order to investigate the effects of a typical solar park on the microclimate and ecosystem processes, we measured soil and air microclimate, vegetation and greenhouse gas emissions for twelve months under photovoltaic (PV) arrays, in gaps between PV arrays and in control areas at a UK solar park sited on species-rich grassland. Our results show that the PV arrays caused seasonal and diurnal variation in air and soil microclimate. Specifically, during the summer we observed cooling, of up to 5.2 °C, and drying under the PV arrays compared with gap and control areas. In contrast, during the winter gap areas were up to 1.7 °C cooler compared with under the PV arrays and control areas. Further, the diurnal variation in both temperature and humidity during the summer was reduced under the PV arrays. We found microclimate and vegetation management explained differences in the above ground plant biomass and species diversity, with both lower under the PV arrays. Photosynthesis and net ecosystem exchange in spring and winter were also lower under the PV arrays, explained by microclimate, soil and vegetation metrics. These data are a starting point to develop understanding of the effects of solar parks in other climates, and provide evidence to support the optimisation of solar park design and management to maximise the delivery of ecosystem services from this growing land use.
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Impact of an Agriphotovoltaic System on Metabolites and the
Sensorial Quality of Cabbage (Brassica oleracea var. capitata)
and Its High-Temperature-Extracted Juice

This report discusses the goal of agrisolar systems, which would generate electricity from raised solar panels and allow crop cultivation under the solar panels, and their development. Details of the report include the effect of raised solar panels and their effect on shading, which affects factors of the crops development. This information can be used to potentially optimize the design of agrisolar operations to most effectively benefit the crops included in the agrisolar operation.
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Lettuce Production under Mini-PV Modules Arranged in Pattern Designs

This study examines a variety of percentages of the total area covered with shade produced by photovoltaic modules on rooftop lettuce crops. The results of the study suggest that in areas of high radiation and temperature(s), it is possible to use the same area on rooftops to produce photovoltaic energy and effectively cultivate plant species that demand little sunlight, such as lettuce. These conclusions mean that rooftop agrisolar is effective when the strategies in this study are taken into consideration.
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Native Vegetation Performance Under a Solar PV Array at the National Wind Technology Center

Implications for vegetation growth when large opaque objects such as solar collectors are placed between the sun and ground-level vegetation across large portions of earth surface have received little attention to date. The present study seeks to address this void, advancing the state of knowledge of how constructed PV arrays affect ground-level environments, and to what degree plant cover, having acceptable characteristics within engineering constraints, can be re-established and thrive.
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Agrivoltaics Provide Mutual Benefits Across the Food-Energy-Water Nexus in Drylands

The vulnerabilities of our food, energy, and water systems to projected climatic change make building resilience in renewable energy and food production a fundamental challenge. We investigate a novel approach to solve this problem by creating a hybrid of colocated agriculture and solar photovoltaic (PV) infrastructure.