Productivity and radiation use efficiency of lettuces grown in the partial shade of photovoltaic panels

Combining photovoltaic panels (PVPs) and crops on the same land unit were recently proposed as an alternative to the conversion of cropland into photovoltaic plants. This could alleviate the increasing competition for land between food and energy production. In such agrivoltaic systems, an upper layer of PVPs partially shades crops at ground level. The aim of this work was to (i) assess the effect on crop yield of two PVPs densities, resulting in two shade levels equal to 50% and 70% of the incoming radiation and (ii) identify morphological and physiological determinants of the plant response to shade. Experiments were conducted on four varieties of lettuces (two crisphead lettuces and two cutting lettuces), during two seasons. In all cases, the relative lettuce yield at harvest was equal or higher than the available relative radiation. Lettuce yield was maintained through an improved Radiation Interception Efficiency (RIE) in the shade, while Radiation Conversion Efficiency (RCE) did not change significantly. Enhanced RIE was explained by (i) an increase in the total leaf area per plant, despite a decrease in the number of leaves and (ii) a different distribution of leaf area among the pool of leaves, the maximal size of leaves increasing in the shade. Our result provides a framework for the selection of adapted varieties according to their morphological traits and physiological responses to PVP shade, in order to optimize agrivoltaic systems

Policy and Environmental Implications of Photovoltaic Systems in Farming in Southeast Spain: Can Greenhouses Reduce the Greenhouse Effect?

Solar photovoltaic (PV) systems have grown in popularity in the farming sector, primarily because land area and farm structures themselves, such as greenhouses, can be exploited for this purpose, and, moreover, because farms tend to be located in rural areas far from energy production plants. In Spain, despite being a country with enormous potential for this renewable energy source, little is being done to exploit it, and policies of recent years have even restricted its implementation. These factors constitute an obstacle, both for achieving environmental commitments and for socioeconomic development. This study proposes the installation of PV systems on greenhouses in southeast Spain, the location with the highest concentration of greenhouses in Europe. Following a sensitivity analysis, it is estimated that the utilization of this technology in the self-consumption scenario at farm level produces increased profitability for farms, which can range from 0.88% (worst scenario) to 52.78% (most favorable scenario). Regarding the Spanish environmental policy, the results obtained demonstrate that the impact of applying this technology mounted on greenhouses would bring the country 38% closer to reaching the 2030 greenhouse gas (GHG) target. Furthermore, it would make it possible to nearly achieve the official commitment of 20% renewable energies by 2020. Additionally, it would have considerable effects on the regional socioeconomy, with increases in job creation and contribution to gross domestic product (GDP)/R&D (Research and Development), allowing greater profitability in agrifood activities throughout the entire region

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

Agrivoltaic systems: a literature review

Agrivoltaic systems integrate solar energy generation with agricultural production to achieve efficient land use and mitigate climate change. This study presents a bibliometric analysis of the scientific literature on this topic, published from 2013 to 2023, to identify key trends, research areas, and emerging topics. Using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology and data from the Scopus database, the analysis was conducted with the R package bibliometrix and VOSviewer software. The results show remarkable growth in scientific output since 2020, with the United States, China, and Germany as the leading countries. The findings reveal the benefits of agrivoltaic systems, such as increased crop productivity, water-use efficiency, and income diversification for farmers. Emerging topics include the optimization of panel configurations and socioeconomic implications. Despite these benefits, challenges like high initial costs, social acceptance, and the need for adaptable designs persist. The conclusions underscore the importance of specific policies and incentives to support the adoption of these technologies. This analysis provides a comprehensive overview of the state of agrivoltaic systems, offering valuable insights for researchers, policymakers, and other stakeholders

Technical Potential and Challenges for Agrivoltaic Development in Nigeria

The co-location of agriculture and solar photovoltaic (PV) infrastructure, known as agrivoltaics, is an increasingly popular practice that offers co-benefits like reduced plant drought stress and improved yields of shade-tolerant crops, particularly in water-scarce agricultural regions. Despite its global growth, knowledge on the technical potential, opportunities, and challenges for agrivoltaic development remains limited in the Global South. Here we address this knowledge gap for Nigeria, Africa’s most populous country, by identifying high-potential regions based on the premise that agrivoltaic co-benefits are generally most pronounced in arable lands with both high solar irradiation and water stress. We find that northern regions, where cropland is abundant and electricity access is low, exhibit high potential for co-benefits due to their dry climate and strong solar irradiance. This includes two of the Nigeria’s most populous states, Kano and Katsina. In contrast, the humid forest regions of southern Nigeria—including Lagos, another populous state—have limited cropland, lower solar irradiance, and thus lower potential for agrivoltaic co-benefits. Further, our findings reveal that northern states could fully meet their projected solar energy capacity expansions through agrivoltaics by covering modest portions of their cropland (\u3c5%), whereas southern states would require substantial shares, often approaching full coverage of available cropland, for similar outcomes. Despite this potential, we identify several potential challenges for agrivoltaics buildout, including high initial costs, land ownership disputes, technical expertise gaps, and regional security concerns. Our analysis provides an initial assessment of agrivoltaics’ technical potential in Nigeria and highlights potential obstacles to overcome for the successful integration of solar power with agriculture

The Effect of Agrivoltaics on Irrigation Water Consumption in Central California

An agricultural system where solar energy generation and agricultural systems are used together for mutual benefit, agrivoltaics reduces loss of water due to evaporation, particularly in drylands. Central California has faced extreme droughts, and water has become a scarce resource. However, the wide-scale use of agrivoltaics has been limited due to lack of knowledge about agrivoltaics and also the lack of funding for start-up agrivoltaics projects. Therefore, this research investigated the potential for agrivoltaics in Central California to reduce irrigation water consumption using a review of multiple crop studies using agrivoltaics to determine an optimal crop for agrivoltaics and a high revenue crop in California. A Suitability Model was created using Geospatial Information Systems software by comparing climate conditions and crop location to determine areas suitable for agrivoltaics. This study looked at policies on agrivoltaics and provided possible inclusions to future bills, in order to better incentivize agrivoltaics installation. Agrivoltaics could be a potential solution to water scarcity in California by reducing irrigation water usage, ultimately providing resiliency for tomato crop farms during drought conditions and decreased water supply

Exploring the potential of agrivoltaics to integrate energy production, agriculture and wildlife

The world faces pressing challenges in reducing greenhouse gas emissions and mitigating the impacts of climate change. Failure to address these issues could result in global average temperatures surpassing the 1.5-degree goal set by the United Nations, leading to severe consequences. Simultaneously, land use change and loss of nature pose significant threats to biodiversity and ecosystem services. Agrivoltaic systems, which integrate solar energy production with agricultural activities, could serve as a valuable approach in addressing these challenges. This thesis explores the design considerations for agrivoltaic systems, focusing on their impact on wildlife, agricultural production, and electricity generation. The research aims to provide insights into optimizing agrivoltaic system design to minimize negative impacts on wildlife while ensuring efficient agricultural and renewable energy production. The analysis of various solar panel configurations and their suitability for different agricultural practices reveals the potential of agrivoltaics to enhance crop production, particularly in dry conditions. The thesis presents several design proposals and principles, such as prioritizing site selection, incorporating wildlife-friendly features, and adapting row spacing and panel height, to address the different considerations. However, the lack of comprehensive studies and empirical data specific to Norway and temperate regions presents challenges in fully understanding the potential and limitations of agrivoltaic systems in these contexts. The thesis emphasizes the importance of further research, field trials, and long-term monitoring to assess the performance, challenges, and opportunities of agrivoltaic systems under local conditions

UTILITY SCALE AGRIVOLTAICS DEVELOPMENT PROXIMATE TO MICHIGAN COMMUNITIES WITH 100% RENEWABLE ENERGY GOALS

This report aims to assess the potential of agrivoltaics (combined solar and agricultural systems) for development geographically proximate to the six Michigan (MI) communities that have set 100% renewable energy (RE) goals. I focus on one major research question: What is the total acreage of low-impact sites available for utility-scale (USS) agrivoltaics development proximate (within county boundaries) to MI communities with 100% RE goals? SAM is used to estimate land acreage required for a 10 MW agrivoltaic system development. ArcGIS Pro is used to determine the total acreage of low-impact sites proximate to MI communities with 100% RE goals. Proximate low-impact sites are defined as agricultural land with minimal environmental and land use impacts, having access to transmission and distribution infrastructure, and are located within the same county as the community with the RE goal. This study finds that USS agrivoltaics development is possible in all six counties. On the premise that the benefits and ills of an energy technology should be distributed equitably within society regardless of social and economic factors, USS agrivoltaic systems could provide a source of revenue for farmers and promote local employment within the county. In addition, such systems can help support the state of MI to achieve its current RPS of 15% and carbon neutrality by 2050. This report provides a first step in assessing the potential of agrivoltaic development in Michigan, which can inform future work that integrates other considerations relevant to solar development

Influence of the Albedo on Agrivoltaics Electricity Production

This paper aims to quantify to what extent the electricity production of two types of agrivoltaics installations (fixed vertical bifacial and horizontal single axis tracker) is affected by the installation of different ground cloths. In order to assess the potential benefits of the use of these cloths, a series of ray-tracing simulations and an extensive measurement campaign were conducted. For the fixed vertical bifacial system, the simulations showed that the white ground cloth should result in an average increase in incident irradiance of about 8% for simulated periods occurring in both March (+8.2%) and June (+7.3%). However, measurements on the vertical bifacial setup over a period of 5.5 months indicated that no measurable differences occurred between the different ground covers. Measurements on the tracker setup did show a clear measurable difference with an average increase of 25% in cumulative rear incident irradiance, also resulting in an increase in revenues, for the tracker with the white ground cloth compared to the reference tracker

Agrivoltaic System: a Case Study of PV Production and Olive Cultivation in Southern Italy

The double use of the land in the AgriVoltaic (AV) sites allows to "doubly harvest from the sun", increasing the land use exploitation with lower environmental impact. This effect strongly depends on the system configuration for both the PV and agricultural sides. The choice is between a high-density PV module arrangement, with high PV production and low agricultural harvesting, or a highly spaced arrangement with lower PV production. The present work presents a case study in Southern Italy: the simulated PV plant can have two different layouts (rated power of 7.13 MW or 5.68 MW), and each hectare can include the plantation of about 900 Arbequina olive trees