Entries by Carl Berntsen

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Solar Photovoltaic Architecture and Agronomic Management in Agrivoltaic System: A Review

Agrivoltaic systems (AVS) offer a symbiotic strategy for co-location sustainable renewable energy and agricultural production. This is particularly important in densely populated developing and developed countries, where renewable energy development is becoming more important; however, profitable farmland must be preserved. As emphasized in the Food-Energy-Water (FEW) nexus, AVS advancements should not only focus on energy management, but also agronomic management (crop and water management). The researchers critically review the important factors that influence the decision of energy management (solar PV architecture) and agronomic management in AV systems. The outcomes show that solar PV architecture and agronomic management advancements are reliant on (1) solar radiation qualities in term of light intensity and photosynthetically activate radiation (PAR), (2) AVS categories such as energy-centric, agricultural-centric, and agricultural-energy-centric, and (3) shareholder perspective (especially farmers). Next, several adjustments for crop selection and management are needed due to light limitation, microclimate condition beneath the solar structure, and solar structure constraints. More importantly, a systematic irrigation system is required to prevent damage to the solar panel structure. The advancements of AVS technologies should not only focus on energy management, but also food (agriculture) and water management, as these three factors are nexus domains. Since the management of agriculture (crop) and water are parts of agronomic management, future enhancements should emphasize the importance of balancing the two. The agronomic management in AV systems that requires improvement includes crop selection recommendations, improved crop management guidelines, and a systematic irrigation system that minimizes environmental impacts caused by excess water and subsequent agrichemical leaching that could affect the solar PV structure. In conclusion, the advancements of AVS technology are expected to reduce reliance on nonrenewable fuel sources and mitigate the effects of global warming, as well as addressing the food-energy-water nexus’s demands.

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Semi-Transparent Organic Photovoltaics Applied as Greenhouse Shade for Spring and Summer Tomato Production in Arid Climate

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semitransparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section, after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.

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Guide to Farming Friendly Solar

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.

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Exploring Farming and Solar Synergies: An Analysis Using Maryland Data

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.

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Agrivoltaic Systems Design and Assessment: A Critical Review, and a Descriptive Model towards a Sustainable Landscape Vision (Three-Dimensional Agrivoltaic Patterns)

As an answer to the increasing demand for photovoltaics as a key element in the energy transition strategy of many countries—which entails land use issues, as well as concerns regarding landscape transformation, biodiversity, ecosystems and human well-being—new approaches and market segments have emerged that consider integrated perspectives. Among these, agrivoltaics is emerging as very promising for allowing benefits in the food–energy (and water) nexus. Demonstrative projects are developing worldwide, and experience with varied design solutions suitable for the scale up to commercial scale is being gathered based primarily on efficiency considerations; nevertheless, it is unquestionable that with the increase in the size, from the demonstration to the commercial scale, attention has to be paid to ecological impacts associated to specific design choices, and namely to those related to landscape transformation issues. This study reviews and analyzes the technological and spatial design options that have become available to date implementing a rigorous, comprehensive analysis based on the most updated knowledge in the field, and proposes a thorough methodology based on design and performance parameters that enable us to define the main attributes of the system from a trans-disciplinary perspective. The energy and engineering design optimization, the development of new technologies and the correct selection of plant species adapted to the PV system are the areas where the current research is actively focusing in APV systems. Along with the continuous research progress, the success of several international experiences through pilot projects which implement new design solutions and use different PV technologies has triggered APV, and it has been met with great acceptance from the industry and interest from governments. It is in fact a significant potential contribution to meet climate challenges touching on food, energy, agriculture and rural policies. Moreover, it is understood—i.e., by energy developers—as a possible driver for the implementation of large-scale PV installations and building integrated agriculture, which without the APV function, would not be successful in the authorization process due to land use concerns. A sharp increase is expected in terms of number of installations and capacity in the near future. Along this trend, new concerns regarding landscape and urban transformation issues are emerging as the implementation of APV might be mainly focused on the efficiency of the PV system (more profitable than agriculture), with insufficient attention on the correct synergy between energy and food production. The study of ecosystem service trade-offs in the spatial planning and design for energy transition, to identify potential synergies and minimize trade-offs between renewable energy and other ecosystem services, has been already acknowledged as a key issue for avoiding conflicts between global and local perspectives. The development of new innovative systems (PV system technology) and components (photovoltaic devices technology) can enhance the energy performance of selected design options for APV greenhouse typology.

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Agrivoltaics Provide Mutual Benefits Across the Food-Energy-Water Nexus in Drylands

Researchers present here a novel ecosystems approach—agrivoltaics—to bolster the resilience of renewable energy and food production security to a changing climate by creating a hybrid of colocated agriculture and solar PV infrastructure, where crops are grown in the partial shade of the solar infrastructure. They suggest that this energy- and food-generating ecosystem may become an important—but as yet quantitatively uninvestigated—mechanism for maximizing crop yields, efficiently delivering water to plants and generating renewable energy in dryland environments. We demonstrate proof of concept for agrivoltaics as a food–energy–water system approach in drylands by simultaneously monitoring the physical and biological dimensions of the novel ecosystem. We hypothesized that colocating solar and agricultural could yield several significant benefits to multiple ecosystem services, including (1) water: maximizing the efficiency of water used for plant irrigation by decreasing evaporation from soil and transpiration from crop canopies, and (2) food: preventing depression in photosynthesis due to heat and light stress, thus allowing for greater carbon uptake for growth and reproduction. An additional benefit might be (3) energy: transpirational cooling from the understorey crops lowering temperatures on the underside of the panels, which could improve PV efficiency. We focused on three common agricultural species that represent different adaptive niches for dryland environments: chiltepin pepper (Capsicum annuum var. glabriusculum), jalapeño (C. annuum var. annuum) and cherry tomato (Solanum lycopersicum var. cerasiforme). We created an agrivoltaic system by planting these species under a PV array—3.3m off the ground at the lowest end and at a tilt of 32°—to capture the physical and biological impacts of this approach. Throughout the average three-month summer growing season we monitored incoming light levels, air temperature and relative humidity continuously using sensors mounted 2.5m above the soil surface, and soil surface temperature and moisture at 5-cm depth. Both the traditional planting area (control) and agrivoltaic system received equal irrigation rates, and we tested two irrigation scenarios—daily irrigation and irrigation every 2d. The amount of incoming photosynthetically active radiation (PAR) was consistently greater in the traditional, open-sky planting area (control plot) than under the PV panels. This reduction in the amount of incoming energy under the PV panels yielded cooler daytime air temperatures, averaging 1.2+0.3 °C lower in the agrivoltaics system over the traditional setting. Night-time temperatures were 0.5+0.4 °C warmer in the agrivoltaics system over the traditional setting (Fig. 2b). Photosynthetic rates, and therefore growth and reproduction, are also regulated by atmospheric dryness, as represented by vapour pressure deficit (VPD) where lower VPD indicates more moisture in the air. VPD was consistently lower in the agrivoltaics system than in the traditional growing setting, averaging 0.52+0.15 kPa lower across the growing season. Having documented that an agrivoltaic installation can significantly reduce air temperatures, direct sunlight and atmospheric demand for water relative to nearby traditional agricultural settings, we address several questions regarding impacts of the food–energy–water nexus system.

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NY Solar Guidebook

This guidebook is a compilation of information, tools, and step-by-step instructions to support local governments with the development, installation, and maintenance of solar energy projects in their communities.

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Will Section 94-C Enable Renewable Energy Project Siting and Help New York State Achieve Its Energy Targets?

This Note examines how Section 94-C is an improvement from earlier siting regimes in NYS, which emphasized a time intensive and comprehensive approval process primarily tailored to the environmental and socioeconomic impacts of fossil-fuel power projects. This Note explains how Section 94-C sought to bridge the historical disconnect between old siting statutes with NYS’s more recent priorities for renewable energy adoption and addressing climate change. This Note demonstrates how Section 94-C can bypass massive delays, provided that ORES establishes more reasonable and predictable substantive standards, as well as reduces the complexity and extent of procedural requirements for developers.

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Standards and Requirements for Solar Equipment, Installation, and Licensing and Certification: A Guide for States and Municipalities

This is one of six program guides being produced by the Clean Energy States Alliance (CESA) as part of its Sustainable Solar Education Project. The project aims to provide information and educational resources to help states and municipalities ensure that distributed solar electricity remains consumer friendly and its benefits are accessible to low- and moderate-income households

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Long Island Solar Roadmap: Advancing Low-Impact Solar in Nassau & Suffolk Counties

Solar power offers Long Islanders a host of benefits — reductions in greenhouse gases and air pollution, healthier communities, affordable access to renewable energy, and good paying jobs. Solar can also play a significant role in helping address the climate crisis and meeting the goals of New York’s Climate Leadership and Community Protection Act (CLCPA). This nation-leading 2019 law requires 70% of the state’s electricity to be generated from renewable resources by 2030 and 100% of electricity to be generated from carbon-free sources by 2040. Many people are familiar with residential rooftop solar systems, which range in size from 3 to 10 kilowatts (kW). Larger commercial and utility-scale solar systems, which can generate hundreds to thousands of kilowatts each, offer the opportunity to realize the benefits of solar power more quickly and cost-effectively in the region. This report shows how solar power can be scaled up without impacting the natural areas that are critical for wildlife, water-quality protection, and quality of life on Long Island. Low-impact sites like rooftops, parking lots, and other land already impacted by development, such as capped landfills and remediated brownfields, are excellent locations for the development of commercial- and utility-scale arrays. Building solar on low-impact sites minimizes impacts to natural ecosystems and habitat, reduces the potential for land-use conflicts and community opposition, decreases project cost and permitting times, and avoids the harmful release of carbon pollution that results from the conversion of natural areas for development. The Nature Conservancy and Defenders of Wildlife created the Long Island Solar Roadmap (the Roadmap) with the aim of advancing deployment of mid- to-large-scale solar power on Long Island in a way that minimizes environmental impacts, maximizes benefits to the region, and expands access to solar energy, including access to benefits by underserved communities. The Roadmap’s creation was supported by a diverse group of Long Island stakeholders. Individuals from state, local, and county government; the solar industry; the farm community; environmental and community organizations; the electric utility; businesses; and academic institutions provided input and guidance on design, research, and strategies. The Roadmap identifies low-impact sites for solar arrays on Long Island and shows their energy generation potential. Key findings also highlight Long Islanders’ opinions and preferences about solar development in their communities and provide information about the costs and benefits associated with bringing more solar online. It is our hope that the cohesive set of strategies and actions provided in this report will help lower barriers to low-impact solar development that meets the needs of all Long Island communities and benefits the whole region. Together, the key findings of the Roadmap point toward a promising future for Long Island as we transition to renewable energy. Taking full advantage of Long Island’s solar potential will require the commitment and collective action of a diverse group of stakeholders, including local and state government, Long Island Power Authority (LIPA), PSEG Long Island, the solar industry, commercial and industrial property owners, farmers and farmland owners, nonprofits, and community organizations.