Analysis of spatial fixed PV arrays configurations to maximize energy harvesting in BIPV applications

This paper presents a new approach for efficient utilization of building integrated photovoltaic (BIPV) systems under partial shading conditions in urban areas. The aim of this study is to find out the best electrical configuration by analyzing annual energy generation of the same BIPV system, in terms of nominal power, without changing physical locations of the PV modules in the PV arrays. For this purpose, the spatial structure of the PV system including the PV modules and the surrounding obstacles is taken into account on the basis of virtual reality environment. In this study, chimneys which are located on the residential roof-top area are considered to create the effect of shading over the PV array. The locations of PV modules are kept stationary, which is the main point of this paper, while comparing the performances of the configurations with the same surrounding obstacles that causes partial shading conditions. The same spatial structure with twelve distinct PV array configurations is considered. The same settling conditions on the roof-top area allow fair comparisons between PV array configurations. The payback time analysis is also performed with considering local and global maximum power points (MPPs) of PV arrays by comparing the annual energy yield of the different configurationsPeer ReviewedPostprint (author’s final draft

PV installations based on vertically mounted bifacial modules evaluation of energy yield and shading effects

Bifacial solar modules promise an increased energy yield, compared to systems with standard, monofacial panels, and also offer new opportunities with regard to the installation. One particular approach is the vertical mounting of PV modules, which is reported to be an effective measure to avoid soiling or dust deposition and is an option to obtain a broadened energy generation profile. In spite of the general interest in this type of installation, the amount of published data is very limited, especially with regard to arrays, for which pronounced shading effects can be expected. In this work we present an analysis of the energy yield and the respective losses for arrays of vertically mounted bifacial solar modules with varied installation conditions

Design of Improved Soft Computing based Maximum Power Point Tracking System for Operational Efficiency Enhancement of Solar Photovoltaic Energy System

The most promising renewable energy source is solar energy, which has enormous potential but has not yet been fully investigated or converted into useful power. The process of converting solar radiation into electrical power is marked by fluctuations in output and waste. These losses are associated with the processes of conversion, transformation, and usage. Temperature, irradiance, and shade are the main operating conditions that affect how well a solar photovoltaic system performs. The efficiency with which power is converted from the panel to the load determines the operational efficiency. Charge controllers are made to convert solar photovoltaic power into electricity for an external circuit. The goal of the research is to look into efficient algorithms that can improve the solar photovoltaic energy system's operating efficiency. In order to increase the operational efficiency of solar photovoltaic systems, research is concentrated on developing maximum power point tracking systems (MPPT) under a variety of operating scenarios, including partial shade and fluctuating irradiance. The performance of the system under various operating conditions has been investigated through the simulation of an equivalent mathematical model. A unique method for charge controller duty cycle control and solar system cooling has been developed. It is based on hybridization of PV-T System and cuckoo search optimization. Simulations of the suggested system have been run under standard, complex, and changing shading pattern and operating conditions. Simulations have shown that the devised method performs better in terms of tracked power, tracking time, and tracking stability. Comparing the suggested research to heuristic approaches based on conventional and soft computing, the solar photovoltaic system's operational performance is much improved

Opto-Electro-Thermal Approach to Modeling Photovoltaic Performance and Reliability from Cell to Module

Thanks to technology advancement in recent decades, the levelized cost of electricity (LCOE) of solar photovoltaics (PV) has finally been driven down close to that of traditional fossil fuels. Still, PV only provides approximately 0.5% of the total electricity consumption in the United States. To make PV more competitive with other energy resources, we must continuously reduce the LCOE of PV through improving their performance and reliability. As PV efficiencies approach the theoretical limit, however, further improvements are difficult. Meanwhile, solar modules in the field regularly fail prematurely before the manufacturers 25-year warranty. Therefore, future PV research needs innovative approaches and inventive solutions to continuously drive LCOE down. In this work, we present a novel approach to PV system design and analysis. The approach, comprised of three components: multiscale, multiphysics, and time, aims at systemically and collaboratively improving the performance and reliability of PV. First, we establish a simulation framework for translating the cell-level characteristics to the module level (multiscale). This framework has been demonstrated to reduce the cell-to-module efficiency gap. The framework also enables the investigation of module-level reliability. Physics-based compact models -the building blocks for this multiscale framework are, however, still missing or underdeveloped for promising materials such as perovskites and CIGS. Hence, we have developed compact models for these two technologies, which analytically describe salient features of their operation as a function of illumination and temperature. The models are also suitable for integration into a large-scale circuit network to simulate a solar module. In the second aspect of the approach, we study the fundamental physics underlying the notorious self-heating effects for PV and examine their detrimental influence on the electrical performance (multiphysics). After ascertaining the sources of self-heating, we propose novel optics-based self-cooling methodologies to reduce the operating temperature. The cooling technique developed in this work has been predicted to substantially enhance the efficiency and durability of commercial Si solar modules. In the third and last aspect of the approach, we have established a simulation framework that can forward predict the future energy yield for PV systems for financial scrutiny and inversely mine the historical field data to diagnose the pathology of degraded solar modules (time). The framework, which physically accounts for environmental factors (e.g., irradiance, temperature), can generate accurate projection and insightful analysis of the geographic-and technology-specific performance and reliability of solar modules. For the forward modeling, we simulate the optimization and predict the performance of bifacial solar modules to rigorously evaluate this emerging technology in a global context. For the inverse modeling, we apply this framework to physically mine the 20-year field data for a nearly worn-out silicon PV system and successfully pin down the primary degradation pathways, something that is beyond the capability of conventional methods. This framework can be applied to solar farms installed globally (an abundant yet unexploited testbed) to establish a rich database of these geographic-and technology-dependent degradation processes, a knowledge prerequisite for the next-generation reliability-aware design of PV systems. Finally, we note that the research paradigm for PV developed in this work can also be applied to other applications, e.g., battery and electronics, which share similar technical challenges for performance and reliability

Assessment of the photovoltaic potential at urban level based on 3D city models: A case study and new methodological approach

The use of 3D city models combined with simulation functionalities allows to quantify energy demand and renewable generation for a very large set of buildings. The scope of this paper is to determine the solar photovoltaic potential at an urban and regional scale using CityGML geometry descriptions of every building. An innovative urban simulation platform is used to calculate the PV potential of the Ludwigsburg County in south-west Germany, in which every building was simulated by using 3D city models. Both technical and economic potential (considering roof area and insolation thresholds) are investigated, as well as two different PV efficiency scenarios. In this way, it was possible to determine the fraction of the electricity demand that can be covered in each municipality and the whole region, deciding the best strategy, the profitability of the investments and determining optimal locations. Additionally, another important contribution is a literature review regarding the different methods of PV potential estimation and the available roof area reduction coefficients. An economic analysis and emission assessment has also been developed. The results of the study show that it is possible to achieve high annual rates of covered electricity demand in several municipalities for some of the considered scenarios, reaching even more than 100% in some cases. The use of all available roof space (technical potential) could cover 77% of the region’s electricity consumption and 56% as an economic potential with only high irradiance roofs considered. The proposed methodological approach should contribute valuably in helping policy-making processes and communicating the advantages of distributed generation and PV systems in buildings to regulators, researchers and the general public

Review of mismatch mitigation techniques for PV modules

The installation of photovoltaic (PV) systems is continuously increasing in both standalone and grid-connected applications. The energy conversion from solar PV modules is not very efficient, but it is clean and green, which makes it valuable. The energy output from the PV modules is highly affected by the operating conditions. Varying operating conditions may lead to faults in PV modules, e.g. the mismatch faults, which may occur due to shadows over the modules. Consequently, the entire PV system performance in terms of energy production and lifetime is degraded. To address this issue, mismatch mitigation techniques have been developed in the literature. In this context, this study provides a review of the state-of-the-art mismatch mitigation techniques, and operational principles of both passive and active techniques are briefed for better understanding. A comparison is presented among all the techniques in terms of component count, complexity, efficiency, cost, control, functional reliability, and appearance of local maximums. Selected techniques are also benchmarked through simulations. This review serves as a guide to select suitable techniques according to the corresponding requirements and applications. More importantly, it is expected to spark new ideas to develop advanced mismatch mitigation techniques.</p

A 3-D Pareto-based shading analysis on solar photovoltaic system design optimization

Peer ReviewedPostprint (author's final draft

Effects of Dynamic Shading on Thermal Exergy and Exergy Efficiency of a Photovoltaic Array

In this study, the effects of dynamic shading caused by an incorrectly positioned transformer building in a Photovoltaic array were investigated regarding the exergy efficiency and thermal exergy for a year. Experimental and theoretical results show that the thermal exergy is affected by the surface temperature of solar panels depending on their shading ratio. In addition, as the shading ratio increases, the electrical exergy and power conversion efficiency decrease. It is also seen that the thermal exergy and exergy efficiency of the PV power system is negatively affected by the increasing solar cell temperature. The average shading ratio of 3.11% during a year causes an increase of about 23.32% of the thermal exergy, and loss in power conversion efficiency of about 4.88% and loss in exergy efficiency of about 13.72% over a year. Overall, it can be concluded that the long-term shading will significantly adversely affect the PV array performance in terms of electrical exergy and thermal exergy

OPTIMUM TILT ANGLE AND NEAR SHADING ANALYSIS FOR 1000 WATT PEAK PHOTOVOLTAIC APPLICATION SYSTEM

Teknologi pemanfaatan energi matahari mengalami peningkatan dan berperan peran penting dalam mendukung kebutuhan energi di masa depan sehingga mampu didistribusikan secara luas. Dalam tulisan ini penentuan sudut kemiringan atau tilt angle yang optimal dan sudut azimuth optimal panel photovoltaic, menggunakan PVSyst simulation software. Studi ini didasarkan nilai radiasi matahari global dan temperatur permukaan horizontal. Sudut kemiringan optimal untuk setiap bulan memungkinkan kita untuk mengumpulkan energi matahari maksimum pertahun. Hasil pemodelan yang dilakukan pada sistem PLTS 1000 Wp di lintang 6˚53'2.69"S dan bujur 107˚32'28.69", menghasilkan kerugian rata-rata 0.6%, dan global irradiance yang mampu diserap oleh panel surya adalah 1747 kWh/m2 pertahun dengan sudut kemiringan panel surya 15˚. Hasil simulasi faktor near shading menunjukkan faktor bayangan pada luas daerah yang diarsir setiap modul surya adalah 0.68 m2