The Study of Decrement in Insulation Resistance of PV String and its Effects on PV System Degradation

2016 ◽  
Vol 675-676 ◽  
pp. 734-738 ◽  
Author(s):  
Nopphadol Sitthiphol ◽  
Chatchai Sirisamphanwong ◽  
Nipon Ketjoy ◽  
Kobsak Sriprapha

This paper presents the investigated variations in insulation resistances of amorphous silicon (a-Si), multi crystalline silicon (MC-Si) and hybrid solar cell (HIT). The insulation resistance of PV string of each system was measured and used to represent leakage current in photovoltaic system and the analysis was done in accordance with IEC 61215 Standard. The 10.152 kW multi-PV cell technologies grid connected system supports the energy demand of the 10 kW Building at School of Renewable Energy Technology (SERT), Naresuan University since July 2005 till date. In general the system was found effectively working under hot and humid climatic conditions of Thailand for a long duration. However the decrement in insulation resistance (MΩ) of a-Si string, MC-Si string and HIT string have affected electrical parameter of each system. The decrements in fill factor (F.F) over the 10 years period (July 13, 2005 – January 25, 2015) of a-Si, MC-Si and HIT were-27.4%, -21.9% and-6.2% respectively.

Author(s):  
K. Agyenim-Boateng ◽  
R. F. Boehm

The promise of large-scale use of renewables such as wind and solar for supplying electrical power is tempered by the sources’ transient behavior and the impact this would have on the operation of the grid. One way of addressing this is through the use of supplemental energy storage. While the technology for the latter has not been proven on a large scale or to be economical at the present time, some assessments of what magnitude is required can be made. In performing this work we have used NREL’s Solar Advisor Model (SAM 2010) with TMY3 solar data to estimate the photovoltaic system power generation. Climatic conditions close to load centers were chosen for the simulations. Then the PV output for varying sizes of arrays were examined and the impact of varying amounts of storage investigated. The storage was characterized by maximum limiting energy and power capacities based on annual hourly peak load, as well as its charging and discharging efficiencies. The simulations were performed using hourly time steps with energy withdrawn from, or input to, storage only after considering base generation and the PV system output in serving the grid load. In this work, we examined the load matching capability of solar PV generation (orientated for maximum summer output) for a sample Southwestern US utility grid load of 2008. Specifically we evaluated the daily and seasonal peak load shifting with employing varying storage capacities. The annual average energy penetration based on the usable solar PV output is also examined under these conditions and at different levels of system flexibility.


2018 ◽  
Vol 19 (4) ◽  
pp. 790-816 ◽  
Author(s):  
Paula Fonseca ◽  
Pedro Moura ◽  
Humberto Jorge ◽  
Aníbal de Almeida

Purpose The purpose of this study was to design a renovation plan for a university campus building (Department of Electrical and Computer Engineering) with the aim to achieve nearly zero energy performance, ensuring a low specific demand (lower than 44 kWh/m2) and a high level of on-site renewable generation (equivalent to more than 20 per cent of the energy demand). Design/methodology/approach The baseline demand was characterized based on energy audits, on smart metering data and on the existing building management system data, showing a recent reduction of the electricity demand owing to some implemented measures. The renovation plan was then designed with two main measures, the total replacement of the actual lighting by LEDs and the installation of a photovoltaic system (PV) with 78.8 kWp coupled with an energy storage system with 100 kWh of lithium-ion batteries. Findings The designed renovation achieved energy savings of 20 per cent, with 27.5 per cent of the consumed energy supplied by the PV system. This will ensure a reduction of the specific energy of the building to only 30 kWh/m2, with 42.4 per cent savings on the net-energy demand. Practical implications The designed renovation proves that it is possible to achieve nearly zero energy goals with cost-effective solutions, presenting the lighting renovation and the solar PV generation system a payback of 2.3 and 6.9 years, respectively. Originality/value This study innovated by defining ambitious goals to achieve nearly zero energy levels and presenting a design based on a comprehensive lighting retrofit and PV generation, whereas other studies are mostly based on envelope refurbishment and behaviour changes.


TECCIENCIA ◽  
2021 ◽  
Vol 16 (31) ◽  
pp. 15-28
Author(s):  
Asad A. Naqvi ◽  
Talha Bin Nadeem ◽  
Ahsan Ahmed ◽  
Asad Ali Zaidi

Off-grid Photovoltaic (PV) system along with battery storage is very effective solution for electrification in remote areas. However, battery capacity selection is the most challenging task in system designing. In this study, an off-grid PV system along with battery storage is designed for the remote area of Karachi, Pakistan. The system is designed by considering the maximum energy requirement in summer season. The battery storage is selected to fulfill the energy demand during the night and cloudy seasons. On the basis of load, a total of 6 kW system is required to fulfill the energy demand. For such system, 925 Ah of battery is required to meet the energy requirement for a day in absence of solar irradiation. A regression-based correlation between battery capacity and energy demand is prepared for suitable battery sizing using Minitab. An economic analysis of the project is also carried out from which a net present value and simple payback are determined as USD 10,348 and 3 years, respectively. The environmental benefits are also been determined. It is found that the system will reduce around 7.32 tons of CO2 per annum which corresponds to the 183.69 tons of CO2 not produced in the entire project life.


Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 149 ◽  
Author(s):  
Henrik Zsiborács ◽  
Nóra Hegedűsné Baranyai ◽  
Szilvia Csányi ◽  
András Vincze ◽  
Gábor Pintér

The energy demand of mankind is constantly growing, thus the utilization of various renewable energy sources, which also reduces negative environmental effects, is becoming more and more important. Because of the achievement of climate protection targets, photovoltaic (PV) energy has an increasing role in the global energy mix. This paper presents the technical and economic aspects of different photovoltaic system configurations designed to suit the Hungarian renewable energy regulations. In this study, five alternative PV configurations were examined for systems with a capacity from 50 kW to 500 kW, related to low- and medium-voltage installations. This article also introduces and explains the Hungarian economic PV and Feed-in-Tariff (FiT) regulations, where three different investment alternatives are analyzed with the help of economic indicators. This study could help stakeholders in the market (e.g., the Hungarian industry sector and local governments) understand the possible directions of technical and economic PV development. According to the results, the payback periods in all the studied economic-technical cases were below 10 years. The experimental results show that each investment option may be a good decision from an economic and technical point of view under the Hungarian regulations in force in 2019.


Author(s):  
Anand S. Joshi ◽  
Ibrahim Dincer ◽  
Bale V. Reddy

In this paper, an attempt is made to investigate the thermodynamic characteristics of a photovoltaic (PV) system based on exergy. A new efficiency is developed that is useful in studying the PV performance and possible improvements. Exergy analysis is applied to a PV system and its components, in order to evaluate the effect of various parameters e.g., voltage, current, area of the PV panel, fill factor and ambient temperature on exergy efficiency. Effect of solar radiation on power conversion efficiency is also evaluated.


2018 ◽  
Vol 49 ◽  
pp. 00014
Author(s):  
Bartosz Chwieduk ◽  
Adam Szelągowski

The paper presents results of analysis of possible cooperation of a photovoltaic system with the space cooling devices. The size of the photovoltaic system was determined on the basis of electricity demand of the selected single family house. The demand for the electricity use for cooling and air conditioning had not been taken into account while calculating the size of PV system. On the basis of the heat balance of the building, the demand for cooling in the following hours of a year was determined. The demand for cooling and heating is affected by the heat transfer through walls, windows, floor, roof, and air exchanged through ventilation. Also solar and internal gains were taken into account. Based on Next, a cooling unit was selected. A cooling device was selected to provide enough energy to maintain the thermal comfort of the building in summer. Taking into account parameters of the selected device, the demand for electricity was determined. Based on time and hours of operation of electrical appliances in the building, a chart of electricity demand was created. The demand for cooling was included. Calculated values of the energy demand required to power all devices in the building were compared with the energy gains from the photovoltaic system. In order to calculate the energy generated by the PV system (in following hours of a year) the isotropic model of solar irradiation was used. The input solar radiation data on horizontal surface were downloaded from the website of the Ministry of Investment and Economic Development. In the last paragraphs, savings obtained in result of using the energy generated by the PV system to drive the space cooling system were determined and conclusions from the calculations were presented.


Author(s):  
Mostafizur Rahman ◽  
Md. Mahmudur Rahman

This paper presents a detailed theoretical study of photovoltaic (PV) systems and their operation using the MPPT (Maximum Power Point Tracking) method and presents the simulation of photovoltaic modules validated by computer software simulation followed by an experimental setup of MATLAB R2017a. The first approach to build the performance of a photovoltaic solar panel is to use a maximum power point tracker in rapidly changing climatic conditions and use a DC-DC converter to maximize the output power. This framework can operate at the maximum power point MPP and produces its highest power in different irradiance conditions when the solar panels are partially shaded. The main perspectivesis design and simulation of a simple but efficient charge controller by utilizing maximum power point tracker for photovoltaic system and analysis results show that this MPPT system with perturb & observe (P&O) method and the DCDC Boost converter can significantly increase the efficiency and the performance of PV.


Author(s):  
F. Slama ◽  
H. Radjeai ◽  
S. Mouassa ◽  
A. Chouder

Purpose. In last decade the problem of energy management system (EMS) for electric network has received special attention from academic researchers and electricity companies. In this paper, a new algorithm for EMS of a photovoltaic (PV) grid connected system, combined to an storage system is proposed for reducing the character of intermittence of PVs power which infect the stability of electric grid. In simulation model, the PV system and the energy storage system are connected to the same DC bus, whereas EMS controls the power flow from the PV generator to the grid based on the predetermined level of PV power. In the case where the PV power is less than the predefined threshold, energy is stored in the batteries banc which will be employed in the peak energy demand (PED) times. Otherwise, it continues to feed the principal grid. The novelty of the proposed work lies in a new algorithm (smart algorithm) able to determine the most suitable (optimal) hours to switching between battery, Solar PVs, and principal grid based on historical consumption data and also determine the optimal amount of storage energy that be injected during the peak demand. Methods. The solution of the problem was implemented in the Matlab R2010a Platform and the simulation conducted on Laptop with a 2.5 GHz processor and 4 GB RAM. Results. Simulation results show that the proposed model schedules the time ON/OFF of the switch in the most optimal way, resulting in absolute control of power electric path, i.e. precise adaptation at the peak without compromising consumers comfort. In addition, other useful results can be directly obtained from the developed scheme. Thus, the results confirm the superiority of the proposed strategy compared to other improved techniques.


Author(s):  
Wojciech RZEŹNIK ◽  
Ilona RZEŹNIK ◽  
Paulina MIELCAREK

Farm buildings have a large number of unused roofs, where photovoltaic panels may be installed without limiting the agricultural land. In piggeries the largest demand for electricity has the ventilation system. The daily distribution of electricity demand is correlated to the diurnal variation of solar radiation. This allows immediate use the energy produced by photovoltaic panels. The aim of the study was to determine the energy demand of the ventilation system, to design a photovoltaic system for its operation and to determine the CO2 emission reduction. The research was carried out for the deep-litter piggery located in Poland. The demand for electricity was determined on the basis of three-year measurements of electricity consumption in the studied piggery. The photovoltaic system was designed to power the ventilation system. Mean annual demand was 26046 kWh. The designed PV system has power of 27 kWp (23984 kWh yr-1). Energy deficits (4591 kWh·yr-1) were noted for 8 months, and energy surpluses (2528 kWh·yr-1) for 4 months in a year. The reduction of CO2 emissions resulting from the use of a photovoltaic system to supply the ventilation system is 19.1 Mg CO2·yr-1 and represents 3% of the total greenhouse gases emissions from the piggery, expressed in CO2 equivalent. It may increase to 8.6% in case of installing the maximum number of PV panels system (maximum power of 78 kWp; total energy production 68526 kWh yr-1) on the southern part of the roof, but it requires the financial support for renewable energy by the government.


Clean Energy ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 273-287
Author(s):  
Ahmad Mayyas ◽  
Assia A Chadly ◽  
Iman Khaleel ◽  
Maher Maalouf

Abstract Green buildings have become broadly adopted in commercial and residential sectors with the objective of minimizing environmental impacts through reductions in energy usage and water usage and, to a lesser extent, minimizing environmental disturbances from the building site. In this paper, we develop and discuss a techno-economic model for a green commercial building that is 100% powered by a photovoltaic (PV) system in stand-alone configuration. A medium-sized office building in El Paso, TX was modelled to rely on a photovoltaic system to supply all of its electricity needs either directly from the PV system or through an energy-storage system (ESS) using Li-ion batteries (LIBs) or reversible fuel cells (RFCs). Cost results show that a 400-kW PV system can generate electricity at a cost of 2.21 cents/kWh in El Paso, TX and the average levelized cost of energy storage (LCOS) using 450-kW RFC is ~31.3 cents/kWh, while this could reach as low as 25.5 cents/kWh using a small LIB ESS. While the RFC provides the flexibility required to meet building-energy demand, LIBs may not be able to meet building needs unless the storage size is increased substantially, which in turn incurs more energy-storage cost, making LIBs less favourable from an economic perspective. Sensitivity analysis revealed that capital cost, discount rate and expected system lifetime play key roles in shaping the LCOS in both systems.


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