The 5 Cs of Agrivoltaic Success Factors in the United States: Lessons From the InSPIRE Research Study

This report examines the NREL Innovative Solar Practices Integrated with Rural Economies and Ecosystems (InSPIRE) project, which was funded by the U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO) starting in 2015. Over the past seven years, the project’s multiple phases have studied the colocation of solar with crops, grazing cattle or sheep, and/or pollinator-friendly native plants, and the resulting ecological and agricultural benefits.

According to InSPIRE research, there are five central elements that lead to agrivoltaic success:

  • Climate, Soil, and Environmental Conditions – The location must be appropriate for both solar generation and the desired crops or ground cover. Generally, land that is suitable for solar is suitable for agriculture, as long as the soil can sustain growth.
  • Configurations, Technologies, and Designs – The choice of solar technology, the site layout, and other infrastructure can affect everything from how much light reaches the solar panels to whether a tractor, if needed, can drive under the panels.
  • Crop Selection and Cultivation Methods, Seed and Vegetation Designs, and Management Approaches – Agrivoltaic projects should select crops or ground covers that will thrive in the local climate and under solar panels, and that are profitable in local markets.
  • Compatibility and Flexibility – Agrivoltaics should be designed to accommodate the competing needs of solar owners, solar operators, and farmers or landowners to allow for efficient agricultural activities.
  • Collaboration and Partnerships – For any project to succeed, communication and understanding between groups is crucial.

Successes and failures of prior agrivoltaic projects will inform new innovations as agrivoltaic projects continue to be deployed globally. This report represents a synthesis of lessons learned from agrivoltaic research field sites located across the United States as part of the InSPIRE project. The projects considered represent a diverse mix of geographies, agrivoltaic activities, and technology configurations. In this report, we have provided a list of features that contribute to the success of agrivoltaic installations and research projects, with partnerships playing a crucial role in both. The researchers suggest future research activities that align with these core principles as well as other approaches to grow agrivoltaic research efforts globally.

83566Download
,

Geospatial Assessment of Elevated Agrivoltaics on Arable Land in Europe to Highlight the Implications on Design, Land Use and Economic Level

Agrivoltaic systems have an increasing interest. Realizing this upcoming technology raises still many challenges at design, policy and economic level. This study addresses a geospatial methodology to quantify the important design and policy questions across Europe. An elevated agrivoltaic system on arable land is evaluated: three crop light requirements (shade-loving, shade-tolerant and shade-intolerant) are simulated at a spatial resolution of 25 km across the European Union (EU). As a result, this study gives insight into the needed optimal ground coverage ratio (GCR) of the agrivoltaic system for a specific place. Additionally, estimations of the energy production, levelized cost of energy (LCOE) and land equivalent ratio (LER) are performed in comparison with a separated system. The results of the study show that the location-dependent solar insolation and crop shade tolerance have a major influence on the financial competitiveness and usefulness of these systems, where a proper European policy system and implementation strategy is required. Finally, a technical study shows an increase in PV power of 1290 GWp (almost × 10 of the current EU’s PV capacity) if potato cultivation alone (1% of the total arable agricultural area) is converted into agrivoltaic systems.

1-s2.0-S2352484722012185-mainDownload

Open-Source Design and Economics of Manual Variable-Tilt Angle DIY Wood-Based Solar Photovoltaic Racking System

Fixed-tilt mechanical racking, consisting of proprietary aluminum extrusions, can dominate the capital costs of small-scale solar photovoltaic (PV) systems. Recent design research has shown that wood-racking can decrease the capital costs of small systems by more than 75% in North America. To determine if wood racking provides enough savings to enable labor to be exchanged profitably for higher solar electric output, this article develops a novel variable tilt angle open-source wood-based do-it-yourself (DIY) PV rack that can be built and adjusted at exceptionally low costs. A detailed levelized cost of electricity (LCOE) production analysis is performed after the optimal monthly tilt angles are determined for a range of latitudes. The results show the racking systems with an optimal variable seasonal tilt angle have the best lifetime energy production, with 5.2% more energy generated compared to the fixed-tilt system. Both fixed and variable wooden racking systems show similar LCOE, which is only 29% of the LCOE of commercial metal racking.

 



designs-06-00054-small

,

Tunable Photovoltaics: Adapting Solar Cell Technologies to Versatile Applications

This report discusses the main principles of different tuning approaches in customizable photovoltaic designs and provides an overview of relevant concepts of tunable SC technologies. The report provides a systematic analysis addressing photovoltaic materials, electrode layers, optical structures, substrates and encapsulates. Also included is a summary of integrations of cutting-edge tunable PV adapted to versatile applications, current challenges, and insightful perspectives into potential future opportunities for tunable PV systems.

Advanced-Energy-Materials-2022-Meddeb-Tunable-Photovoltaics-Adapting-Solar-Cell-Technologies-to-VersatileDownload
, ,

Waveguide Concentrator Photovoltaic with Spectral Splitting for Dual Land Use

This research presents a highly transparent concentrator photovoltaic system with solar spectral splitting for dual land use applications. The system includes a freeform lens array and a planar waveguide. Sunlight is first concentrated by the lens array and then reaches a flat waveguide. The dichroic mirror with coated prisms is located at each focused area at the bottom of a planar waveguide to split the sunlight spectrum into two spectral bands. The red and blue light, in which photosynthesis occurs at its maximum, passes through the dichroic mirror and is used for agriculture. The remaining spectrums are reflected at the dichroic mirror with coated prisms and collected by the long solar cell attached at one end of the planar waveguide by total internal reflection. Meanwhile, most of the diffused sunlight is transmitted through the system to the ground for agriculture. The system was designed using the commercial optic simulation software LightTools™ (Synopsys Inc., Mountain View, CA, USA). The results show that the proposed system with 200× concentration can achieve optical efficiency above 82.1% for the transmission of blue and red light, 94.5% for diffused sunlight, which is used for agricultural, and 81.5% optical efficiency for planar waveguides used for power generation. This system is suitable for both high Direct Normal Irradiance (DNI) and low DNI areas to provide light for agriculture and electricity generation at the same time on the same land with high efficiency.

energies-15-02217Download
, ,

Modeling the Ecosystem Services of Native Vegetation Management Practices at Solar Energy Facilities in the Midwestern United States

In this paper, the researchers applied the InVEST modeling framework to investigate the potential response of four ecosystem services (carbon storage, pollinator supply, sediment retention, and water retention) to native grassland habitat restoration at 30 solar facilities across the Midwest United States.

1-s2.0-S2212041620301698-mainDownload
, ,

Technoeconomic Model Suggests Scaling-Up Perovskite Quantum Dots for Optoelectronics Warrants Improved Synthesis Yield, Solvent Recycling, and Automation

Colloidal quantum dots (QDs) are nanometer-sized semiconductor crystals grown via low-cost solution processing routes for a wide array of applications encompassing photovoltaics, light-emitting diodes (LEDs), electronics, photodetectors, photocatalysis, lasers, drug delivery, and agriculture. A comprehensive technoeconomic cost analysis of perovskite quantum dot optoelectronics is reported. Using economies-of-scale considerations based on price data from prominent materials suppliers, we have highlighted that increased QD synthesis yield, solvent recycling, and synthesis automation are critical to market adoption of this technology and driving quantum dot film fabrication costs down from >$50/m^2 to ∼$2−3/m^2

acsenergylett.2c00250Download
, , ,

Ground Irradiance Modelling: Of Key Importance for Designing Nature Inclusive Solar Parks and Agrivoltaics Systems

Solar electricity from solar parks in rural areas are cost effective and can be deployed fast therefore play an important role in the energy transition. The optimal design of a solar park is largely affected by income scheme, electricity transport capacity, and land lease costs. Important design parameters for utility-scale solar parks that may affect landscape, biodiversity, and soil quality are ground coverage ratio, size, and tilt of the PV tables. Particularly, low tilt PV at high coverage reduces the amount of sunlight on the ground strongly and leads to deterioration of the soil quality over the typical 25-year lifetime. In contrast, vertical PV or an agri-PV designed fairly high above the ground leads to more and homogeneous ground irradiance; these designs are favored for pastures and croplands. In general, the amount and distribution of ground irradiance and precipitation will strongly affect which crops can grow below and between the PV tables and whether this supports the associated food chain. As agrivoltaics is the direct competition between photosynthesis and photovoltaics. Understanding when, where and how much light reaches the ground is key to relate the agri-PV solar park design to the expected agricultural and electricity yields. We have shown that by increasing the minimum height of the system, decreasing the size of the PV tables and decreasing the coverage ratio, the ground irradiance increases, in particular around the gaps between the tables. The most direct way of increasing the lowest irradiance in a solar park design is to use semi-transparent PV panels, such as the commercially available bifacial glass-glass modules. In conclusion: we have shown that we can achieve similar ground irradiance levels in an east- and west-facing design with 77% ground coverage ratio as is achieved by a south-facing design at 53% coverage.

GROUND-IRRADIANCE-MODELLING-OF-KEY-IMPORTANCE-FOR-DESIGNING-NATURE-INCLUSIVE-SOLAR-PARKS-AND-AGRIVOLTAICS-SYSTEMSDownload
, ,

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.

Agrivoltaic-Systems-Design-and-Assessment-1
, ,

Wavelength-Selective Solar Photovoltaic Systems: Powering Greenhouses for Plant Growth at the Food-Energy-Water Nexus

Wavelength-Selective Photovoltaic Systems (WSPVs) combine luminescent solar cell technology with conventional silicon-based PV, thereby increasing efficiency and lowering the cost of electricity generation. WSPVs absorb some of the blue and green wavelengths of the solar spectrum but transmit the remaining wavelengths that can be utilized by photosynthesis for plants growing below. WSPVs are ideal for integrating electricity generation with glasshouse production, but it is not clear how they may affect plant development and physiological processes. The effects of tomato photosynthesis under WSPVs showed a small decrease in water use, whereas there were minimal effects on the number and fresh weight of fruit for a number of commercial species. Although more research is required on the impacts of WSPVs, they are a promising technology for greater integration of distributed electricity generation with food production operations, for reducing water loss in crops grown in controlled environments, as building-integrated solar facilities, or as alternatives to high-impact PV for energy generation over agricultural or natural ecosystems.

WavelengthSelective-PV-Powering-Greenhouses