Entries by Carl Berntsen

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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.

Pollinator-Friendly Solar Scorecards

The push toward carbon-free and renewable energy sources has precipitated a nationwide (United States) trend to increase solar generation via ground-mounted photovoltaic (PV) arrays. Beyond carbon benefits, one possible way to provide additional ecological value of solar PV projects is to co-locate pollinator habitat when site conditions permit. Around 2015, the concept of a “scorecard” emerged that could assess the value of a solar project to pollinator species. The development and application of these scorecards, to date, has not been controlled by any central organization. Scorecards are being developed on a state-by-state basis using various processes, by a variety of subject matter experts, and using a range of oversight and review approaches. As such, there is variation between different state scorecard programs and divergent opinions regarding the scorecards themselves. Given that developing state and local laws and incentive programs are linked to the pollinator-friendly solar scorecards, it is important to consider the basis of the scorecards themselves. With interest in co-location of solar with pollinator habitat, this comprehensive study of existing pollinator solar scorecards considers the level of consistency across the scorecards, analyzes the specific scorable elements and their relative weighting, and investigates the factors that influenced scorecard development. A total of 15 state scorecards and one nonspecific scorecard available as of April 2021 were reviewed to identify common and differentiating features. A categorization system for individual scoring elements was created to facilitate numeric assessment across the available scorecards. Further, in order to understand the unique motivations and processes that influenced the design of the scorecards, interviews were conducted with 34 experts involved in scorecard design, policy development, and use, including university professors, state agency staff, and solar project developers, owners, and operators. Research uncovered a general lack of rigor, consistency, and oversight for scorecard design methodology, version control, and use. However, if the scorecards can be predictive of ecological outcomes – healthy pollinator habitat – then they may still be meeting their primary purpose. Field-based research is necessary to determine if there is a correlation between the points received on a pollinator-friendly scorecard and the actual solar PV site habitat conditions.

Lego Solar Farm Prize for Best Photo Taken During the Follow the Sun Tour

AgriSolar Clearinghouse partner Rob Davis has generously offered a full Solar Farm Lego set as a prize for the winner of the competition for best photo taken at one of the Follow the Sun tour field trips. This set is priceless and can not be purchased.  If you support the idea of a real-life Lego […]

Soil Properties Changes After Seven Years of Ground Mounted Photovoltaic Panels in Central Italy Coastal Area

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.

Techno-economic feasibility analysis of Benban solar Park

By 2035, Egypt pursues to generate 22% of the total electricity from photovoltaic power plants to meet the national spreading demand for electricity. The Egyptian government has implemented feed-in tariffs (FiT) support program to provide the economic incentives to invest in the PV power plants. The present study is carried out to evaluate the techno-economic feasibility of a largescale grid-connected photovoltaic (LS GCPV) of the Benban Solar Park with a total capacity of 1600 MW AC producing annual electricity of 3.8 TWh. The characteristics of PV panels considering the meteorological data of Benban Solar Park are evaluated. Additionally, the reduction of greenhouse gas (GHG) emissions due to constructing Benban Solar Park is assessed. As well, the influences of annual operation and maintenance cost and the interest rate on the electricity cost and the payback period are evaluated. The results indicate that the electricity cost is about 8.1¢US/kWh with 10.1 years payback period, which is indeed economically feasible with an interest rate of 12%. Furthermore, the Benban Solar Park will avoid annually almost 1.2 million tons of greenhouse gas. The working conditions of the previous study which aimed to improve the performance of solar panels using cooling water are similar to the Benban solar Park. This study showed that utilizing of water cooling for solar panels leads to an increase in the electrical energy output by 8.2%. This attributed to maximizing the benefit when cultivating the vast land area on which the station is built, and using the irrigation water to cool the PV panels, and then for the irrigation process. Thus, a double advantage can be achieved; first, an increase in the electrical energy output by 8.2% in the summer months where the panel surface temperature is high. Second, the agricultural crops as an economic value, as the solar panels are located at a height of 1.5m from the surface of the earth. The PV solar panels are installed above the existing cultivated areas while the maintained spaces among rows of PV modules provide the necessary solar radiation for crops.

Techno Economic Modeling for Agrivoltaics: Can Agrivoltaics be more profitable than Ground mounted PV?

Agrivoltaics is a dual land-use approach to collocate solar energy generation with agriculture for preserving the terrestrial ecosystem and enabling food-energy-water synergies. Here, we present a systematic approach to model the economic performance of agrivoltaics relative to standalone ground-mounted PV and explore how the module design configuration can affect the dual food-energy economic performance. A remarkably simple criterion for economic feasibility is quantified that relates the land preservation cost to dual food-energy profit. We explore case studies including both high and low value crops under fixed tilt bifacial modules oriented either along the conventional North/South facings or vertical East/West facings. For each module configuration, the array density is varied to explore an economically feasible design space relative to ground-mounted PV for a range of module to land cost ratio (𝑴𝑳) – a location-specific indicator relating the module technology (hardware and installation) costs to the soft (land acquisition, tax, overheads, etc.) costs. To offset a typically higher agrivoltaic module cost needed to preserve the cropland, both East/West and North/South orientated modules favor high value crops, reduced (<60%) module density, and higher 𝑴𝑳 (>𝟐𝟓). In contrast, higher module density and an increased feed-in-tariff (𝑭𝑰𝑻) relative to ground-mounted PV are desirable at lower 𝑴𝑳. The economic trends vary sharply for 𝑴𝑳< 10 but tend to saturate for 𝑴𝑳> 20. For low value crops, ~15% additional 𝑭𝑰𝑻 can enable economic equivalence to 𝑮𝑴𝑷𝑽 at standard module density. Researchers have presented a techno-economic modeling framework to assess and predict the economic performance of 𝐴𝑉 systems relative to the standard ground mounted 𝑃𝑉. The effects of module design configurations including array density and orientation, income from crop, technology specific and land related costs, and 𝐹𝐼𝑇 are explored. To support cropland preservation, 𝐴𝑉 typically has a higher module technology cost as compared to standard 𝑃𝑉 primarily due to elevated mounting and customized foundations that can potentially make it economically non-attractive for 𝑃𝑉 investors. They show that it is possible to design an economically attractive 𝐴𝑉 system by selecting suitable crops and module configuration for the given land costs and 𝐹𝐼𝑇.

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.

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Agrivoltaic Systems Enhance Farmers’ Profits through Broccoli Visual Quality and Electricity Production without Dramatic Changes in Yield, Antioxidant Capacity, and Glucosinolates

This paper shows that agrivoltaic systems allow us to reach sustainable food and electricity goals
with high land-use efficiency. The study shows the yield, antioxidant capacity, and secondary metabolite
of broccoli and electricity production were analyzed under an agrivoltaic system over three cultivation
periods. The study also reports that agrivoltaic with additional shading treatment produced greener broccoli with a higher level of consumer preference than open-field grown ones.