In this study, researchers used field measurements and a plant hydraulic model to quantify carbon-water cycling in a semi-arid C3 perennial grassland growing beneath a single-axis tracking solar array in Colorado, USA. Although the agrivoltaic array reduced light availability by 38%, net photosynthesis and aboveground net primary productivity were reduced by only 6–7% while evapotranspiration decreased by 1.3%. The minimal changes in carbon-water cycling occurred largely because plant photosynthetic traits underneath the panels changed to take advantage of the dynamic shading environment. The results indicate that agrivoltaic systems can serve as a scalable way to expand solar energy production while maintaining ecosystem function in managed grasslands, especially in climates where water is more limiting than light.
The objective of this thesis work is to evaluate the introduction of agrivoltaics in Italy through the study of the effect of the presence of photovoltaic panels on the final yield of potatoes in Ferrara, Italy. The findings of this preliminary study indicate that agrivoltaic systems should be designed while taking into account the need to ensure a minimum level of incident radiation at least in the first two months of cultivation, to avoid an inter-row production drop. Furthermore, photovoltaic panels are not responsible for the absolute low yield in years with unfavorable weather conditions, such as cold years; on the contrary, they may mitigate the damages to the crop by creating an underneath microclimate and the resulting higher temperature, which however is a hypothesis to be verified in more detail in future studies.
In this study, researchers monitored the microclimate, soil moisture, panel temperature, electricity generation and soil properties at a utility-scale solar facility in a continental climate with different site management practices. The vegetated solar areas had significantly higher soil moisture, carbon, and other nutrients compared to bare solar areas. However, the benefits of vegetation cooling effects on electricity generation are rather site-specific and depend on the background climate and soil properties.
In this article, researchers evaluated seasonal patterns of soil moisture (SM) and diurnal variation in incident sunlight (photosynthetic photon flux density [PPFD]) in a single-axis-tracking agrivoltaic system established in a formerly managed semiarid C3 grassland in Colorado. Their goals were to (1) quantify dynamic patterns of PPFD and SM within a 1.2 MW photovoltaic array in a perennial grassland, and (2) determine how aboveground net primary production (ANPP) and photosynthetic parameters responded to the resource patterns created by the photovoltaic array. Investigators found relatively weak relationships between SM and ANPP despite significant spatial variability in both. Further, there was little evidence that light-saturated photosynthesis and quantum yield of CO2 assimilation differed for plants growing directly beneath (lowest PPFD) versus between (highest PPFD) PV panels. Overall, the AV system established in this semiarid managed grassland did not alter patterns of ANPP in ways predictable from past studies of controls of ANPP in open grasslands.
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.
Solar energy is the fastest growing renewable energy source. It is predicted that 20-29% of global power will be sourced by solar by 2100. Solar energy requires larger land footprints and long-term commitments. Vegetation left under solar panels reduces soil degradation and opens up the potential for solar grazing as a dual income for farmers and vegetation management for solar utilities. Research conducted on multiple solar sites in Minnesota reveal there can be meaningful forage in 45% shade and 80% shade from solar panels. Furthermore, grazing sheep under solar panels produces both a higher content of carbon and nitrogen in the soil. Managed episodic grazing can be used as a strategy for carbon sequestration and vegetation management. Soil properties show an overall improvement and benefits depending on soil properties. Future work must be done to measure the long term soil carbon and hydrological properties.
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.
Global energy demand is increasing as greenhouse gas driven climate change progresses, making renewable energy sources critical to future sustainable power provision. Land-based wind and solar electricity generation technologies are rapidly expanding, yet our understanding of their operational effects on biological carbon cycling in hosting ecosystems is limited. Wind turbines and photovoltaic panels can significantly change local ground-level climate by a magnitude that could affect the fundamental plant–soil processes that govern carbon dynamics. We believe that understanding the possible effects of changes in ground-level microclimates on these phenomena is crucial to reducing uncertainty of the true renewable energy carbon cost and to maximize beneficial effects. In this Opinions article, we examine the potential for the microclimatic effects of these land-based renewable energy sources to alter plant–soil carbon cycling, hypothesize likely effects and identify critical knowledge gaps for future carbon research. Land use change for land-based renewables (LBR) is global, widespread and predicted to increase. Understanding of microclimatic effects is growing, but currently incomplete, and subsequent effects on plant–soil C cycling, greenhouse gas (GHG) emissions and soil C stocks are unknown. We urge the scientific community to embrace this research area and work across disciplines, including plant–soil ecology, terrestrial biogeochemistry and atmospheric science, to ensure we are on the path to truly sustainable energy provision.
This publication discusses site selection and soil preparation for fruit plantings. It also describes cover crop and mulching options for orchards and vineyard floors, and discusses fertilization and the role of mycorrhizae in maintaining healthy fruit plants. A list of additional resources is included.