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.
The purpose of this paper is to systematically synthesize the potential ecosystem services of agrivoltaics and summarize how these development strategies could address several United Nations Sustainable Development Goals. Led by Agrisolar Clearinghouse partner Leroy Walston, researchers focused on four broad potential ecosystem services of agrivoltaics: (1) energy and economic benefits; (2) agricultural provisioning services of food production and animal husbandry; (3) biodiversity conservation; and (4) regulating ecosystem services such ascarbon sequestration and water and soil conservation.
In this article, researchers argue that the divide between food and energy production groups can be lessened with the co-generation of food and energy on the same land. This paper demonstrates the importance of different light spectra, and show that those spectra, if optimized in terms of their utilization, could lead to sustainable and more efficient food and energy systems.
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.
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.
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.
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.
The triple benefits of the AgriVoltaic Systems Development (AVSD) have been well demonstrated, not only for the PV electricity generation but also for reduced water evaporation, enhancing further the benefits of simultaneously crop growth on the same land area. However, the reduction rate of the water evaporation of AVSD has not been investigated in a quantitative way. Therefore, this study conducted experiments to measure water evaporation reduction under the Concentrated-lighting Agrivoltaic System (CAS) and the Even-lighting Agrivoltaic System (EAS). Evaporation containers and pans were placed in the bare soil (CK) under the CAS and the EAS. Our results showed a significant reduction in water evaporation under CAS and EAS. Cumulative soil surface evaporation of CK, CAS, and EAS for 45 days was 80.53 mm, 63.38 mm, and 54.14 mm. The cumulative water evaporation from soil and pan surfaces decreased by 21 % and 14 % (under CAS), 33 %, and 19 % (under EAS), respectively. The slope β1 ∕= 0 of simple linear regression showed a significant positive relationship between evaporation time and cumulative water evaporation. The correlation coefficient in all treatments was more than 0.91, suggesting a robust linear relationship. The feasibility of AVSD could significantly reduce irrigation water, enhance crop growth, and generate electricity simultaneously on the same agricultural land.
Agrivoltaics is a concept in which a piece of land is simultaneously used for both energy and food production by mounting photovoltaic modules at a certain height above (or in between strips of) agricultural land. A local and system-level incorporation of water management is imperative to the sustainable implementation of agrivoltaics. Water raining on the module can be gathered and used for distinct purposes: groundwater recharge, crop irrigation, and cleaning and cooling of the PV modules. This research provides an initial overview of positive and negative impacts for each water use concept and outlines issues that should be taken into consideration and the potential for research and development. Various Managed Aquifer Recharge (MAR) technologies are a way to clean and store the water periodically in an underlying aquifer. Irrigation increases yield within the plant level and therefore increases the system’s output. Thanks to the power supply generated by the PV modules, high-tech irrigation systems can be implemented in agrivoltaic systems; the special adaption of irrigation systems to agrivoltaics poses significant potential for research and development. Meanwhile, the necessity, i.e., profitability of cleaning and/ or cooling PV modules depends on local environment and economic factors. Several cleaning techniques have been developed to mitigate soiling, ranging from manual cleaning to fully automatic cleaning systems. In agrivoltaics systems, the soiling risk can increase. Semi-automatic systems seem to have the greatest potential for agrivoltaics, because they can be used with farming equipment. Multiple cooling techniques have been developed to decrease cell temperature to increase power output, with some of them involving water. Water flowing over the module surface is a promising a promising cooling technique for agrivoltaic applications. Attaching a perforated tube to the upper edge, the entire module can be covered in a thin film of water which cools very effectively (while also cleaning the surface). A closed-circuit system could be created involving the technical components used for rainwater harvesting. The economic feasibility of cooling panels in agrivoltaic systems needs to be investigated. In certain locations, rainwater-harvesting could also be relevant for ground-mounted PV systems.
Land use change is a major driver of soils’ properties variation and potential degradation. Solar photovoltaic plants installed on the ground represent a key to mitigating global climate change and greenhouse gas emissions. However, it could represent an emerging source of land consumption, although reversible, which prevents the use of soils for agricultural purposes and may affect crucial ecosystems services. Despite the large widespread deployment of photovoltaic plants, their potential effect on soil properties has been poorly investigated. The aim of this study was to assess changes of soil physical, chemical and biochemical properties seven years after the installation of the panels. For this purpose, the soil under photovoltaic panels was compared with the GAP area between the panels’ arrays and with an adjacent soil not affected by the plant. The main results showed that seven years of soil coverage modified soil fertility with the significant reduction of water holding capacity and soil temperature, while electrical conductivity (EC) and pH increased. Additionally, under the panels soil organic matter was dramatically reduced (-61% and -50% for TOC and TN, respectively compared to GAP area) inducing a parallel decrease of microbial activity assessed either as respiration or enzymatic activities. As for the effect of land use change, the installation of the power plant induced significant changes in soils’ physical, chemical and biochemical properties creating a striped pattern that may require some time to recover the necessary homogeneity of soil properties but shouldn’t compromise the future re-conversion to agricultural land use after power plant decommissioning.
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