Solar photovoltaic (PV) systems are frequently installed in climates with significant snowfall. To better understand the effects of snowfall on the performance of PV systems, a multi-angle, multi-technology PV system was commissioned and monitored over two winters. A novel methodology was introduced and validated with this system, which allows for the determination of snowfall losses from time-series performance data with correlated meteorological observations down to a 5-min resolution. In addition, a new method for determining the probability distribution of snow deposition on a module from image data was developed. It was found that the losses due to snowfall are dependent on the angle and technology being considered and the effects of increased albedo in the surroundings of a PV system can increase expected yields, particularly in the case of high tilt angle systems. Existing methods for predicting losses due to snowfall were investigated, and were found to provide overly conservative estimates of snow losses. Overall the results show that the proper assessment of snow related losses can help improve system performance and maintenance. It is concluded that proper characterization of the snowfall effect on PV system performance can influence better systems optimization for climates experiencing snowfall.

This study presents a retrofit strategy: integrating optimized photovoltaics (PV) in the form of responsive shading devices using a dual-axis solar tracking system. A prototype-based model was fabricated to compare the efficiency of PV in this implementation with the conventional fixed installation. The office building, T1 Empire World in Erbil, was selected as a retrofit case study and for the application of the proposed integration system. In order to assess the effectiveness of the proposed retrofit method, the energy performance of the base case is simulated to be compared later with the energy performance simulations after the integration technique. The amount of generated electricity from the PV surfaces of the integrated shading elements is calculated. The energy simulations were performed using OpenStudio ® (NREL, Washington, DC, USA), EnergyPlus TM (NREL, Washington, DC, USA), and Grasshopper/ Ladybug tools in which the essential results were recorded for the baseline reference, as well as the energy performance of the retrofitted building. The results emphasize that the PV-integrated responsive shading devices can maximize the efficiency of PV cells by 36.8% in comparison to the fixed installation. The integrated system can provide approximately 15.39% of the electricity demand for operating the building. This retrofit method has reduced the total site energy consumption by 33.2% compared to the existing building performance. Total electricity end-use of the various utilities was lowered by 33.5%, and the total natural gas end-use of heating demand was reduced by 30.9%. Therefore, the percentage reduction in electricity cooling demand in July and August is 42.7% due to minimizing the heat gain in summer through blocking the sun's harsh rays from penetrating into interior spaces of the building. In general, this system has multiple benefits, starting with being extremely efficient and viable in generating sustainable alternative energy—which is the global growing concern of today's sustainable development—providing thermal comfort for occupants, and granting a dynamic appearance to the building when the PV-integrated elements rotate according to the sun's position in the sky.

Bifacial photovoltaic dual-axis tracker systems have the potential to out-perform other module/mounting configurations at high latitudes, where the reflectivity of snow in winter boosts bifacial performance and the low solar angle-of-incidence favors dual-axis tracking. Two years of empirical data from dual-axis experimental systems in Vermont support this assertion, demonstrating that bifacial modules on a dual-axis tracker produced 14 percent more electricity in a year than their monofacial counterparts and as much as 40 percent during the peak winter months. These bifacial gains are in addition to the estimated 35-40 percent energy gains of a dual-axis tracker relative to a fixed-tilt system. Such findings suggest that bifacial two-axis tracker systems could be economically attractive in northern latitudes, with high-efficiency modules compensating for the trackers' installation and maintenance costs, and future design improvements enabling further performance gains.

Solar photovoltaic (PV) systems have the greatest potential to meet the scale of sustainable energy demands, yet large surface areas beyond rooftop areas are required. One source of additional surface area that avoids conflict with food production while scaling with population density is noise barriers, which provide dual use of land area both as noise abatement and energy generation. This paper provides a method to quantify the potential of mass scale deployment of photovoltaic noise barrier (PVNB) systems in a country. Based on a feasibility analysis of the irradiation levels and noise barrier locations, the PV power potential and the energy output for the photovoltaic modules is calculated for specific locations using a tool chain of free software. This method, is then demonstrated with a case study for the state of California and the results are then extrapolated for the entire U.S. The U.S. is an ideal candidate country because noise abatement mandates fall well short of World Health Organizations guidelines and PVNB technology has not been implemented on a wide scale. Using conservative assumptions, the results show that the total PVNB power potential for the U.S. ranges from 7 to 9 GW using only existing noise barriers. According to findings of the paper the installed capacity of the large scale photovoltaic system deployed on noise barriers in a single state is comparable to the installed capacities of the largest solar farms in the U.S. and yet due to the unique mounting of PVNB, such systems provide better land utilization ratios for energy production than conventional solar PV farms.

This paper elaborates a comprehensive overview of a photovoltaic (PV) system model, and compares the attributes of various conventional and improved incremental conductance algorithms, perturbation and observation techniques, and other maximum power point tracking (MPPT) algorithms in normal and partial shading conditions. Performance evaluation techniques are discussed on the basis of the dynamic parameters of the PV system. Following a discussion of the MPPT algorithms in each category, a table is drawn to summarize their key specifications. In the performance evaluation section, the appropriate PV module technologies, atmospheric effects on PV panels, design complexity, and number of sensors and internal parameters of the PV system are outlined. In the last phase, a comparative table presents performance-evaluating parameters of MPPT design criterion. This paper is organized in such a way that future researchers and engineers can select an appropriate MPPT scheme without complication.

Ground-mounted large photovoltaic (PV) arrays are the least-cost design solution for installing PV, they account for the majority of the solar power installed today. With the increase of both the number and size of installations, the attention to their impacts in terms of land -use and land-transformation is growing, as well as concerns about landscape preservation and possible losses of ecosystem services. The community acceptance is often a barrier. The current design is generally straight-forward and is aimed to the maximize energy generation given a certain land area. This paper brings forward the idea that PV systems should be designed as an element of the landscape they belongs to, according to an 'inclusive' design approach that does not focus only on the overall energy efficiency of the system, but extends to other additional ecological and landscape objectives. An original energy-design vision for on-ground PV is advanced, rooted in an original concept of 'photovoltaic landscape'. An understanding of PV landscapes in terms of patterns is given, and new patterns for PV are investigated. Based on literature new patterns for PV are assessed quantitatively in terms of land use energy intensity; and qualitatively in terms of perception-aesthetics related aspects. Design domain freedom and boundary restrictions have been investigated with reference to possible negative and positive overall ecological performances; the weight of each design parameter has been qualitatively assessed, so that some first design guidelines could be formulated. Furthermore, a quantitative approach for calculating the life cycle costs of the energy generated from PV landscapes, focusing on land use, has been proposed. The study demonstrates that new patterns would help in allowing a better ecological performance of the PV landscape, and opens many research questions, such as the quantitative assessment of the ecological positive impacts generated by new PV patterns.

The economics in the U.S. of solar photovoltaic (PV) systems is changing rapidly as the cost per unit power of PV modules has dropped quickly. These costs reductions have two important results: marked decrease in levelized cost of electricity (LCOE) into ranges competitive or better than traditional electricity-generation technologies and the economic role of racking has been gaining prominence relative to that of modules. As the relative importance of costs of PV racking has been marginal historically, there has been relatively little progress on reducing the materials and costs associated with it, which has caused racking to contribute to a significant portion of costs of entire PV systems. In order to overcome this challenge this study investigates a novel low-weight PV racking system for commercial rooftops based on crossed cables (X-wires) and compares it to racking systems already available on the market on capital costs, labor costs for installation, and technical specifications such as adaptability and power packing factor. The results of over 80% cost reduction and 33% increase in power density are presented and conclusions are drawn about the potential for tension-based racking systems to further reduce total PV systems costs on commercial flat roof tops resulting in LCOE savings of $0.01–$0.02/kW h.

Aggressive growth of land-based solar photovoltaic (PV) farms can create a land use conflict with agricultural production. Fortunately, this issue can be resolved using the concept of agrivoltaics, which is co-development of land area for both solar PV and agriculture. To investigate and quantify PV generation potential, without harming agriculture output, this study explores the viability of agrivoltaic farms deployment on existing grape farms in India. Considering the shade tolerance of grapes, an techno-economicanalysis is run for the installation of PV systems in the area available between the trellises on a grape farm. The electrical energy generation potential is determined per unit area and economic benefits for the cultivators is quantified over a number of design options. The results show the economic value of the grape farms deploying the proposed agrivoltaic systems may increase more than 15 times as compared to conventional farming, while maintaining the same grape production. If this dual use of land is implemented nationwide, it can make a significant impact by generating over 16,000 GWh electricity, which has the potential of meeting the energy demands of more than 15 million people. In addition, grape-based agrivoltaics can be implemented in rural areas to enable village electrification.

Bodies of water provide essentials for both human society as well as natural ecosystems. To expand the services these water provide, hybrid food-energy-water systems can be designed. This paper reviews the fields of floatovoltaic (FV) technology (water deployed solar photovoltaic systems) and aquaculture (farming of aquatic organisms) to investigate the potential of hybrid floatovoltaic-aquaculture synergistic applications for improving food-energy-water nexus sustainability. The primary motivation for combining electrical energy generation with aquaculture is to promote the dual use of water, which has historically high unused potential. Recent advances in FV technology using both pontoon and thin film structures provides significant flexibility in deployment in a range of water systems. Solar generated electricity provides off-grid aquaculture potential. In addition, several other symbiotic relationships are considered including an increase in power conversion efficiency due to the cooling and cleaning of module surfaces , a reduction in water surface evaporation rates, ecosystem redevelopment, and improved fish growth rates through integrated designs using FV-powered pumps to control oxygenation levels as well as LED lighting. The potential for a solar photovoltaic-aquaculture or aquavoltaic ecology was found to be promising. If a U.S. national average value of solar flux is used then current aquaculture surface areas in use, if incorporated with appropriate solar technology could account for 10.3% of total U.S. energy consumption as of 2016.