Tag Archive for: Solar Grazing

This publication reviews planning the use of land for large-scale utility solar energy.

Utility-scale solar development has expanded rapidly across the U.S. in recent years, driven by declining costs and improving technology. The most recent Lazard levelized cost of energy (LCOE) analysis shows utility-scale solar now equivalent to or below the cost of conventional generation, with a price range of $36-44 per megawatt-hour (MWh). Thirty-two gigawatts (GW) of utility-scale solar have been installed in the United States to date, and another 50 GW are planned or in development. By 2030, the Department of Energy SunShot program estimates that solar development will encompass between 1 to 3 million acres of land. As the geographic footprint of solar increases beyond the arid southwestern United States, so too has interest in the land use under the panels. In these new geographies, including the Midwest and Northeast, solar is often sited on agricultural land. The ideal tract of land for solar development is flat, dry, unshaded, and close to transmission and load. All of these characteristics are associated with farmland, raising possible tensions between solar and farming as competing land uses. For the most part, solar developers plant shallow-rooted turfgrass or spread gravel under panels, rendering that land unproductive aside from the generation of electricity. However, the co-location of solar projects and innovative vegetation management plans offers the potential to ameliorate this potential land use conflict. Improving the “landscape compatibility” of utility-scale solar has become a topic of great interest in the energy, land use and agricultural research communities. Examples of co-location include growing crops underneath solar trackers; grazing cattle or sheep among elevated solar panels that also provide shade for the livestock; and installing solar in the non-irrigated corners of center-pivot irrigation plots. These approaches can be grouped under the recently coined umbrella term “agrivoltaics.” The researchers developed an Excel-based modelling tool to understand the tradeoffs, costs and benefits between maintaining land as conventional farmland or converting a portion of it to either a conventional solar facility or a pollinator-friendly solar facility. The model accounts for spatial, economic and environmental differences across three counties in South-central Minnesota: Fillmore, Hennepin and Rock. The model is designed as a cash-flow project finance model that incorporates monetized environmental and social costs and benefits. As project finance is the predominant method for financing solar projects in the United States, and a large proportion of a project’s financial return is delivered through preferred tax status and tax credits, they modeled both pre- and post-tax cash flows from the solar projects. Their model also includes a cash-flow operating model for a conventional soy or corn farm. For all land uses, the model incorporates the monetized value of environmental externalities, including carbon emissions, soil erosion and groundwater recharge. Not all externalities and ecosystem services were modeled, due to data limitations and difficulties in quantifying benefits such as habitat creation and biodiversity. We created multiple scenarios within the model to analyze differences in private and social value streams across counties, crop type, and a range of upside and downside inputs. The model outputs are a series of cost-benefit analyses comparing the three main land uses — pollinator-friendly solar, conventional solar, and farming. The financial return of each use varies by crop type, location and upside/downside scenarios. Solar development in Minnesota and across the Midwest is poised to continue on land traditionally devoted to conventional agriculture. Growing interest in low-impact solar development and co-location of solar projects with pollinator-friendly plants represents an opportunity to mitigate energy-versus-food tensions and provide additional benefits to agriculture, ecosystems, and private developers alike. The model presented in this paper takes an important step towards quantifying and monetizing the benefits of pollinator-friendly solar development as a land use option in Minnesota. Understanding the full monetary value of pollinator-friendly solar is necessary to design policies that efficiently and effectively support its development in locations that optimize project value. As the practice continues to gain popularity, there is a pressing need for additional research that clarifies the value of ecosystem services created by this innovative land use. Improved understanding of the diverse social and private benefits of pollinator-friendly solar will allow for strategic deployment of these projects — and will maximize returns for all stakeholders.

Renewable energy is a promising alternative to fossil fuel based energy, but its development can require a complex set of environmental tradeoffs. A recent increase in solar energy systems, especially large, centralized installations, underscores the urgency of understanding their environmental interactions. Synthesizing literature across numerous disciplines, the researchers review direct and indirect environmental impacts both beneficial and adverse of utility scale solar energy (USSE) development, including impacts on biodiversity, land use and land cover change, soils, water resources, and human health. Additionally, they review feedbacks between USSE infrastructure and land atmosphere interactions and the potential for USSE systems to mitigate climate change. Several characteristics and development strategies of USSE systems have low environmental impacts relative to other energy systems, including other renewables. We show opportunities to increase USSE environmental co benefits, the permitting and regulatory constraints and opportunities of USSE, and highlight future research directions to better understand the nexus between USSE and the environment. Increasing the environmental compatibility of USSE systems will maximize the efficacy of this key renewable energy source in mitigating climatic and global environmental change. Utility scale solar energy systems are on the rise worldwide, an expansion fueled by technological advances, policy changes, and the urgent need to reduce both our dependence on carbon intensive sources of energy and the emission of greenhouse gases to the atmosphere. Recently, a growing interest among scientists, solar energy developers, land managers, and policy makers to understand the environmental impacts both beneficial and adverse of USSE, from local to global scales, has engendered novel research and findings. This review synthesizes this body of knowledge, which conceptually spans numerous disciplines and crosses multiple interdisciplinary boundaries. The disadvantageous environmental impacts of USSE have not heretofore been carefully evaluated nor weighted against the numerous environmental benefits particularly in mitigating climate change and co benefits that solar energy systems offer. Indeed, several characteristics and development strategies of USSE systems have low environmental impacts relative to other energy systems, including other renewable energy technologies. Major challenges to the widespread deployment of USSE installations remain in technology, research, and policy. Overcoming such challenges, high lighted in the previous sections, will require multidisciplinary approaches, perspectives, and collaborations. This review serves to induce communication across relatively disparate disciplines but intentional and structured coordination will be required to further advance the state of knowledge and maximize the environmental benefits of solar energy systems at the utility scale.

This guide has been developed to share knowledge and learnings from agrisolar practices around Australia and the world, to assist proponents of utility-scale solar, and the landholders and farmers who work with them, to integrate agricultural activities into solar farm projects. As solar grazing is the dominant form of agrisolar for utility-scale solar, this guide has a strong focus on sharing the knowledge and learnings from Australian projects that have integrated solar grazing practices to date, providing case studies from solar farms currently employing solar grazing, information on the benefits of solar grazing for proponents and farmers, and practical guidance for both farmers and proponents considering solar grazing. A further aim is to contribute to the local knowledge of trends and research from international markets about a broader range of agrisolar models which could be considered for the Australian context. With the deployment of large utility-scale solar farms commencing in Australia from around 2015 onwards, the local experience of agrisolar practices is still developing and currently dominated by the practice of sheep grazing on solar farms. The first known Australian solar farm to implement agrisolar practice was the Royalla Solar Farm which began grazing sheep in 2015. Since then, there have been over a dozen solar farms that have introduced grazing, and it has proved to be an effective partnership for both solar farm proponents and graziers. ‘Solar grazing’, as it is known, is the most prevalent form of complementary land use for utility-scale solar farms. At present, where other forms of agrisolar are being pursued in horticulture, viticulture, aquaculture and cropping, it is typically at a much smaller (ie. nonutility) scale.

This document focuses specifically on solar energy generation that is designed to be compatible with continued farming, whereby little or no land is taken out of production. Primary agricultural soils are those defined as having the best combination of physical and chemical characteristics for producing food, feed, forage, fiber and oilseed crops. Because of the value of these soils from a productivity standpoint, it is generally desirable to protect them from uses that would otherwise remove them from agricultural use. As is illustrated in the case studies, farming-friendly solar is possible. In the examples, several farms have married on-farm solar with rotational grazing of livestock. Another has located their solar system in a buffer area required as part of their organic certification. As planners, it is important not to simply reject the concept of solar on farms or farmland out of hand. Instead, it is needed to consider how these systems can benefit farmers and how they can be utilized in conjunction with active farming to achieve energy goals and protect the viability of agriculture in communities. All of these farmers were pleased with the arrangement they had made for the dual purposes of grazing and providing land space for solar panel arrays. Yet each one of them also mentioned a deep commitment to preserving the best agricultural land for agricultural uses first – and thus the common refrain of thinking it all through before any breaking of ground. The structures are large and change how the land is used. All encouraged the idea of using lower-impact places such as a roof or land that cannot be used for agricultural purposes, first. And secondly, the importance of a revenue source to the farm/farmer for the use of that land supporting the solar array.

This report explores the synergies between farming and solar photovoltaics with the premises that agricultural production on farmland should be maintained and farm profitability and soil health should be improved. Instead of focusing on solar siting, this report explores whether a strong case can be made from a public policy point of view for developing solar so that it helps to preserve and improve farmland and the ecosystem in which it is located, while enabling achievement of both energy system and food system goals. Three examples, using Maryland data, analyzed in the report illustrate the potential of this dual farming-plus-solar approach, with solar being on 10% or less of the farm operation: (i) solar on 100 acres leased from a 1,000 acre corn-soy commodity crop operation; (ii) solar owned by the farmer on 16 acres of a 300-acre dairy-grazing operation; (iii) solar on one-acre of a ten-acre horticultural farm. In each case profits increase substantially. Farm economic resilience is improved because solar revenues are independent of the vagaries of weather and crop markets. While the examples are Maryland-specific, the approach for analyzing dual-use solar is broadly applicable elsewhere in the United States.

This agreement template example, from the American Solar Grazing Association, Inc., is an example of a limited vegetation maintenance agreement between a solar site manager and a sheep farmer. The example includes terms of the agreement between parties and details regarding obligations under various circumstances for the duration of the contract.

This agreement template example, from the American Solar Grazing Association, Inc., is an example of a comprehensive vegetation maintenance agreement between a solar site manager and a sheep farmer. The example includes instructions for using a contract template, terms of the agreement between parties and details regarding obligations under various circumstances for the duration of the contract.

This is a two-page checklist covering the important issues for both shepherds and solar site managers to consider when managing vegetation under solar panels by grazing sheep. The checklist for solar-site operators includes grazing vs. mowing expectations, insurance updates, and arrangement considerations for the shepherd. The checklist for the shepherd includes determination of fencing plans, maintenance vehicle considerations, signage for property containing grazing animals, and vegetation management plans, among others.

Photovoltaic panels can provide artificial shades to protect livestock against intense solar radiation while serving as a clean energy source. This study determined livestock shade preference between photovoltaic panels and the classical 80% blockage cloth material, and quantified the reduction in radiant heat load provided by these shade structures. The results show that the cattle spent more than 70% of their time in the shade during conditions of the study. These results can be useful in determining best practices on agrisolar operations that include livestock.