scholarly journals Methodology to Determine Photovoltaic Inverter Conversion Efficiency for the Equatorial Region

2019 ◽  
Vol 10 (1) ◽  
pp. 201
Author(s):  
Azhan Ab. Rahman ◽  
Zainal Salam ◽  
Sulaiman Shaari ◽  
Mohd Zulkifli Ramli

Photovoltaic inverter conversion efficiency is closely related to the energy yield of a photovoltaic system. Usually, the peak efficiency (ηmax) value from the inverter data sheet is used, but it is inaccurate because the inverter rarely operates at the peak power. The weighted efficiency is a preferable alternative as it inherently considers the power conversion characteristics of the inverter when subjected to varying irradiance. However, since the weighted efficiency is influenced by irradiance, its value may not be appropriate for different climatic conditions. Based on this premise, this work investigates the non-suitability of the European weighted efficiency (ηEURO) for inverters installed in the Equatorial region. It utilizes a one year data from the Equatorial irradiance profile to recalculate the value of ηEURO (ηEURO_recal) and to compare it with the original ηEURO. Furthermore, a new weighted efficiency formula for the Equatorial climate (ηEQUA) is proposed. Validation results showed that calculated energy yield with ηEQUA closely matched the real energy yield of 3 kW system with only 0.16% difference. It is envisaged that the usage of ηEQUA instead of ηmax or ηEURO will results in a more accurate energy yield and return of investment calculations for PV systems installed in Equatorial regions.

2019 ◽  
Vol 9 (7) ◽  
pp. 1397 ◽  
Author(s):  
Wael Al-Kouz ◽  
Sameer Al-Dahidi ◽  
Bashar Hammad ◽  
Mohammad Al-Abed

This paper proposes computational models to investigate the effects of dust and ambient temperature on the performance of a photovoltaic system built at the Hashemite University, Jordan. The system is connected on-grid with an azimuth angle of 0° and a tilt angle of 26°. The models have been developed employing optimized architectures of artificial neural network (ANN) and extreme learning machine (ELM) models to estimate conversion efficiency based on experimental data. The methodology of building the models is demonstrated and validated for its accuracy using different metrics. The effect of each parameter was found to be in agreement with the well-known relationship between each parameter and the predicted efficiency. It is found that the optimized ELM model predicts conversion efficiency with the best accuracy, yielding an R2 of 91.4%. Moreover, a recommendation for cleaning frequency of every two weeks is proposed. Finally, different scenarios of electricity tariffs with their sensitivity analyses are illustrated.


Author(s):  
Amina Mahmoud Shakir ◽  
Siba Monther Yousif ◽  
Anas Lateef Mahmood

Bifacial photovoltaic (PV) module can gain 30% more energy compared to monofacial if a suitable location were chosen. Iraq (a Middle East country) has a variable irradiation level according to its geographic coordinates, thus, the performance of PV systems differs. This paper an array (17 series, 13 parallel) was chosen to produce 100 kWp for an on-grid PV system. It investigates the PV system in three cities in Iraq (Mosul, Baghdad, and Basrah). Effect of albedo factor, high and pitch of the bifacial module on energy yield have been studied using PVsyst (software). It has been found that the effect is less for a pitch greater than 6 m. The energy gained from bifacial and monofacial PV system module in these cities shows that Mosul is the most suitable for installing both PV systems followed by Baghdad and lastly Basrah. However, in Basrah, the bifacial gain is 12% higher in the energy than monofacial as irradiation there is higher than the other locations, especially for elevation above 1.5 m. Moreover, the cost of bifacial array is 7.23% higher than monofacial, but this additional cost is acceptable since the bifacial gain is about 11.3% higher energy compared to the monofacial.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2360
Author(s):  
Ngoc Hai Vu ◽  
Thanh Tuan Pham ◽  
Seoyong Shin

In this research, we present a novel design for a large scale spectral splitting concentrator photovoltaic system based on double flat waveguides. The sunlight concentrator consists of a Fresnel lens array and double waveguides. Sunlight is firstly concentrated by Fresnel lenses then reaches an upper flat waveguide (UFW). The dichroic mirror-coated prisms are positioned at each focused area to divide the sunlight spectrum into two bands. The mid-energy (mid E) band is reflected at the prism surface and coupled to the UFW. The GaInP/GaAs dual-junction solar cell is attached at the exit port of the UFW to maximize the electrical conversion efficiency of the mid E band. The low-energy (low E) band is transmitted and reaches a bottom flat waveguide (BFW). The mirror coated prisms are utilized to redirect the mid E band sunlight for coupling with the BFW. The GaInAsP/GaInAs dual-junction solar cell is applied to convert the low E band to electricity. The system was modeled using the commercial optic simulation software LightTools™. The results show that the proposed system can achieve optical efficiencies of 84.02% and 80.01% for the mid E band and low E band, respectively, and a 46.1% electrical conversion efficiency for the total system. The simulation of the system performance and comparison with other PV systems prove that our proposed design is a new approach for a highly efficient photovoltaic system.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6757
Author(s):  
Markus Rinio

Having a photovoltaic (PV) system raises the question of whether it runs as expected. Measuring its energy yield takes a long time and the result still contains uncertainties from varying weather conditions and possible shading of the modules. Here, a free software PVcheck to measure the peak power of the system is announced, using the power data of a single sunny day. The software loads a data file of the generated power as a function of time from this day. This data file is provided by typical inverters. The software then simulates this power curve using known parameters like angle and location of the PV system. The assumed peak power of the simulation can then be adjusted so that the simulated curve matches the measured one. The software runs under Microsoft Windows™ and makes use of the free library pvlib python. The simulation can be refined by importing weather data like temperature, wind speed, and insolation. Furthermore, curves describing the nominal module efficiency as a function of the illumination intensity as well as the power-dependent inverter efficiency can be included in the simulation. First results reveal a good agreement of the simulation with experimental data. The software can be used to detect strong problems in PV systems after installation and to monitor their long-time operation.


2020 ◽  
Vol 12 (15) ◽  
pp. 6162
Author(s):  
Mariusz T. Sarniak

The paper analyzes a case study of the impact of changing the nominal power ratio (NPR) on the efficiency of a PV (photovoltaic) system located in Poland. In the first stage of the research, the acceptable range of variability for NPR was determined based on simulation calculations, taking into account the parameters of PV modules, inverter, and climatic conditions. The second stage was verification tests for two acceptable extreme cases, carried out based on the analysis of detailed data from the monitoring of PV installations. The results of the verification tests for the two considered periods of operation of the PV system with the change of the NPR coefficient from 82% to 98% resulted in an increase in the annual energy yield by 446.2 kWh. On the other hand, higher relative values of generated energy were obtained only for the months with the lowest insolation in December and in January by 8.2 and 6.04 kWh/kWp, respectively. Higher oversizing of the PV generator (for NPR = 82%) also resulted in an increase by 6.4% in the frequency of operation of the PV inverter in the largest power range (2250–2500 W) and a decrease by 3.7% in the frequency in the lowest power range (0–250 W) for the whole year.


2021 ◽  
Vol 13 (14) ◽  
pp. 7636
Author(s):  
Khaled M. Alawasa ◽  
Rashid S. AlAbri ◽  
Amer S. Al-Hinai ◽  
Mohammed H. Albadi ◽  
Abdullah H. Al-Badi

For a decade, investments in solar photovoltaic (PV) systems have been increasing exponentially in the Middle East. Broadly speaking, these investments have been facing tremendous challenges due to the harsh weather in this particular part of the world. Dust accumulation is one the challenges that negatively affects the performance of solar PV systems. The overall goal of this paper is to thoroughly investigate the effect of dust accumulation on the energy yield of car park PV systems. With this aim in mind, the paper presents scientific values for further research and opens the horizon for attracting further investments in solar PV systems. This study is based on a real PV system in the Sultanate of Oman and considers different cleaning cycles for 16 months (from 29 July 2018 to 10 November 2019). Furthermore, four different PV groups were assessed, and the system was monitored under different cleaning frequencies. In general, it was found that dust accumulation has a significant impact; under 29-day, 32-day, 72-day, and 98-day cleaning cycles, the average percentages of energy loss due to soiling were 9.5%, 18.2%, 31.13%, and 45.6%, respectively. In addition, the dust effect has a seasonal variation. The study revealed that dust accumulation has a more negative impact during summer than during winter. During summer, the energy losses due to soiling were 8.7% higher than those during winter. The difference was attributed to different environmental conditions, with high humidity and low wind speed being the main factors that worsen the impact of dust during summer. Based on the findings of this research, a monthly cleaning program is highly recommended in the city of Muscat.


2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Hafsa Abouadane ◽  
Abderrahim Fakkar ◽  
Benyounes Oukarfi

The photovoltaic panel is characterized by a unique point called the maximum power point (MPP) where the panel produces its maximum power. However, this point is highly influenced by the weather conditions and the fluctuation of load which drop the efficiency of the photovoltaic system. Therefore, the insertion of the maximum power point tracking (MPPT) is compulsory to track the maximum power of the panel. The approach adopted in this paper is based on combining the strengths of two maximum power point tracking techniques. As a result, an efficient maximum power point tracking method is obtained. It leads to an accurate determination of the MPP during different situations of climatic conditions and load. To validate the effectiveness of the proposed MPPT method, it has been simulated in matlab/simulink under different conditions.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1121
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

A reconfiguration technique using a switched-capacitor (SC)-based voltage equalizer differential power processing (DPP) concept is proposed in this paper for photovoltaic (PV) systems at a cell/subpanel/panel-level. The proposed active diffusion charge redistribution (ADCR) architecture increases the energy yield during mismatch and adds a voltage boosting capability to the PV system under no mismatch by connected the available PV cells/panels in series. The technique performs a reconfiguration by measuring the PV cell/panel voltages and their irradiances. The power balancing is achieved by charge redistribution through SC under mismatch conditions, e.g., partial shading. Moreover, PV cells/panels remain in series under no mismatch. Overall, this paper analyzes, simulates, and evaluates the effectiveness of the proposed DPP architecture through a simulation-based model prepared in PSIM. Additionally, the effectiveness is also demonstrated by comparing it with existing conventional DPP and traditional bypass diode architecture.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2308
Author(s):  
Kamran Ali Khan Niazi ◽  
Yongheng Yang ◽  
Tamas Kerekes ◽  
Dezso Sera

Partial shading affects the energy harvested from photovoltaic (PV) modules, leading to a mismatch in PV systems and causing energy losses. For this purpose, differential power processing (DPP) converters are the emerging power electronic-based topologies used to address the mismatch issues. Normally, PV modules are connected in series and DPP converters are used to extract the power from these PV modules by only processing the fraction of power called mismatched power. In this work, a switched-capacitor-inductor (SCL)-based DPP converter is presented, which mitigates the non-ideal conditions in solar PV systems. A proposed SCL-based DPP technique utilizes a simple control strategy to extract the maximum power from the partially shaded PV modules by only processing a fraction of the power. Furthermore, an operational principle and loss analysis for the proposed converter is presented. The proposed topology is examined and compared with the traditional bypass diode technique through simulations and experimental tests. The efficiency of the proposed DPP is validated by the experiment and simulation. The results demonstrate the performance in terms of higher energy yield without bypassing the low-producing PV module by using a simple control. The results indicate that achieved efficiency is higher than 98% under severe mismatch (higher than 50%).


Author(s):  
VS Chandrika ◽  
M Mohamed Thalib ◽  
Alagar Karthick ◽  
Ravishankar Sathyamurthy ◽  
A Muthu Manokar ◽  
...  

Photovoltaic (PV) system efficiency depends on the geographical location and the orientation of the building. Until installing the building structures, the integration of the PV module must be evaluated with ventilation and without ventilation effects. This work optimises the performance of the 250 kWp grid-connected photovoltaic (GPV) for community buildings in the southern part of India. This simulation is carried out to evaluate the system efficiency of the GPV system under various ventilation conditions, such as free-standing PV (FSPV), building integrated photovoltaic ventilated (BIPV_V) and Building Integrated Photovoltaic without ventilation (BIPV). The PVsyst simulation tool is used to simulate and optimise the performance of the system with FSPV, BIPV and BIPV_V for the region of Chennai (13.2789° N, 80.2623° E), Tamilnadu, India. An annual system energy production is 446 MWh, 409 MWh and 428 MWh of FSPV, BIPV and BIPV_V system respectively. while electrical efficiency for the FSPV, BIPV_V, BIPV system is 15.45%. 15.25% and 14.75% respectively. Practical application: Integrating the grid connected photovoltaic system on the building reduces the energy consumption in the building. The integration of the PV on the roof or semi integrated on the roof is need to be investigated before installing on the buildings. The need for installation of the BIPV with ventilation is explored. This study will assist architects and wider community to design buildings roofs with GPV system which are more aesthetic and account for noise protection and thermal insulation in the region of equatorial climate zones.


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