scholarly journals Performance analysis of photovoltaic plants installed in dairy cattle farms

2015 ◽  
Vol 46 (2) ◽  
pp. 62
Author(s):  
Remo Alessio Malagnino

Electric production from renewable resources, such as solar photovoltaic (PV), is playing an increasingly essential role in the agricultural industry because of the progressive increase in the energy price from fossil fuels and the simultaneous decrease in the income deriving from farming activities. A central issue in the sustainable diffusion of PV technologies is represented by the actual energy efficiency of a PV system. For these reasons, a performance analysis has been carried out in order to assess the potentials offered by different PV plants within a defined geographical context with the aim of investigating the impact of each component has on the PV generator global efficiency and defining the main technical parameters that allow to maximise the annual specific electric energy yield of an architectonically integrated plant, installed in a dairy house, compared to a ground-mounted plant. The annual performances of three grid connected PV plants installed in the same dairy cattle farm have been analysed: two are architectonically integrated plants - <em>i.e.</em>, a rooftop unidirectional and a multi-field systems (both 99 kW<sub>p</sub>) - and the other is a ground-mounted plant (480 kW<sub>p</sub>). Furthermore, the electrical performances, estimated by the photovoltaic geographical information system (PVGIS), developed by the EU Joint Research Centre, and by an analytical estimation procedure (AEP), developed on the basis of a meteo-climatic database related to the records of the nearest weather station and integrated by the components’ technical specifications, have been compared with the actual yields. The best annual performance has been given by the ground-mounted PV system, with an actual increase of 26% and in the range of 6÷12% according to different estimations, compared to the integrated systems, which were globally less efficient (average total loss of 26÷27% compared to 24% of the ground-mounted system). The AEP and PVGIS software estimates showed a good level of reliability for mean deviations between the annual actual and estimated electrical power yields have been equal to 11.5% for each PV system given the actual irradiation’ s uncertainty during the examined year. The main technical parameters, crucial to maximise the energy yield from a ground-mounted PV system to an integrated one, have been identified in the Tilt and Azimuth angles. Indeed, once a variance of 3÷4% in the global efficiency has been confirmed when the type of PV system is changed, in the case of the unidirectional integrated PV plant, the high roof pitch and the almost South orientation guarantee a solar energy increase up to 18% higher than that obtainable on the horizontal plane and similar to the increase estimated for the ground-mounted generator (+20%). Hence, integrated PV systems, besides reaching the same levels of energy efficiency as those ground-mounted, are also more <em>sustainable</em> than the latter. This is true providing that there are both a suitable orientation and an accurate design, especially to prevent the PV panels’ warming during summer, on an already available surface that is, however, functional to the roof’s architecture.

2021 ◽  
Vol 13 (23) ◽  
pp. 13209
Author(s):  
Osama A. Marzouk

An energy modeler for solar photovoltaic (PV) systems may be limited to climatic data of certain major cities, not covering the one for which the PV system is intended. Additionally, a person not skilled in solar PV modeling may still desire a quick estimate of PV system electricity generation to help decide the level of investment in PV systems. This work addresses these points by establishing lookup tables to summarize predicted electricity generation, solar irradiation, and optimum orientation at various locations in the Sultanate of Oman. The results are produced by processing simulation data using the online open-access tool PVGIS (Photovoltaic Geographical Information System) of the European Commission’s Joint Research Centre (EC-JRC). The tables cover 40 out of the country’s 61 s-level administrative divisions (wilayats) and cover fixed and movable PV panels. The results show that the yearly electricity generation can change up to 11.86% due to the change of location. Two-axis PV tracking offers a small improvement (about 4% on average) over single-vertical-axis tracking but offers noticeable improvement (about 34% on average) over optimally oriented fixed PV panels. Monthly profiles of expected PV electricity generation, as well as the generation drop due to changing the PV mounting from free standing to building integrated, were examined for three locations. As general perspectives that may be of interest to global readers, this work provides quantitative evidence of the overall accuracy of the PVGIS-SARAH database through comparison with ground-measured global horizontal irradiation (GHI). In addition, a full example is presented considering 12 different countries in the northern and southern hemispheres that brings the attention of solar energy modelers to the level of errors they may encounter when the impact of longitude (thus, the exact location) is ignored for simplicity, while focus is given to the latitude.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
S. Sánchez-Carbajal ◽  
P. M. Rodrigo

The performance and economics of grid-connected photovoltaic (PV) systems are affected by the array spacing. Increasing the array spacing implies reducing the impact of shading, but at the same time, it increases the land purchase/preparation costs and the wiring costs. A number of technical and economic factors are involved when selecting an optimum array spacing. Designers of PV plants often set the row-to-row spacing based on simplified rules, losing the opportunity of improving the profitability of their projects. In this paper, a comprehensive methodology for optimizing the array spacing is proposed. It is based on annual shading energy calculations and incorporates a PV energy yield model together with an economic model focused on investment costs. The method is applied to the climatic conditions in Aguascalientes, Mexico, as a case study. A sensitivity analysis allowed the impact of the technical and economic parameters involved on the optimum interrow distance to be quantified. According to the results, the most relevant technical parameters are the module tilt (often considered by the PV designers), the ratio of plant width to plant length, and the module efficiency. The main economic parameters are the land-related costs and the costs per kWp. The comparison of this methodology to a conventional rule based on the winter solstice condition shows differences in the array spacing for the same location when the multiple technical and economic parameters are considered. Therefore, the proposed method will be useful for PV designers to improve the energetic and economic behavior of their systems.


2017 ◽  
Vol 15 (2) ◽  
pp. 57-69 ◽  
Author(s):  
Ivana Radonjic ◽  
Tomislav Pavlovic

Soiling is a term used to describe the deposition of dust (dirt) on solar modules, which reduces the amount of solar radiation reaching the solar cells. Deposition of dust on solar modules can make the operation of the entire PV system - more difficult and, therefore, lead to the generation of less electric energy. Soiling of solar modules also influences solar modules parameters (short-circuit current, open-circuit voltage, maximum power, fill factor and efficiency). This paper presents the results of the investigation on the impact different quantities of calcium carbonate (CaCO3) deposition have on the energy efficiency of horizontally mounted solar modules. The short-circuit current, power and efficiency decrease with increasing the mass of CaCO3 deposited on the horizontally mounted solar module. The open-circuit voltage and fill factor very slightly increase with increasing the mass of CaCO3 deposited on the horizontally mounted solar module. Upon soiling with 1 g of calcium carbonate, the solar module efficiency decreased by 4.6% in relation to the clean solar module, upon soiling with 2 g of calcium carbonate it decreased by 6.0%, and upon soiling with 3 g of calcium carbonate it decreased by 12.9% in relation to the clean solar module. It can be concluded that the power and energy efficiency of the solar module decrease due to the increased amount of calcium carbonate.


2020 ◽  
Vol 31 (4) ◽  
pp. 1-15
Author(s):  
Russel Mhundwa ◽  
Michael Simon ◽  
Joel Nana Yongoua

This study presents an analysis of a 75 kWp grid-tied solar photovoltaic (PV) system with a grid tie limiter to provide energy requirements for an aquaculture centre in the Eastern Cape province of South Africa. A data acquisition system, comprising power and energy consumption meters, was deployed to measure solar PV generation, demand for the facility, and energy drawn from the utility grid. Statistical analysis was conducted on the data to determine the impact of the solar PV plant in reducing demand from the utility grid throughout the day, and this was extrapolated into monthly and annual contributions by the PV system to meeting the energy requirements. Findings reveal that the annual energy yield for the system was 1 864.29 kWh/kWp. The solar contribution to the total load requirement on a 24 hour cycle was 28% (139.82 MWh) from July 2018 to June 2019. Summer and winter average contributions by the PV system were 62% and 57% respectively for the period of 05:30–18:30. The mean monthly solar fraction for operating the farm between sunrise and sunset was 0.44. Furthermore, a total of 141.07 tCO2 has been avoided due to the operation of the PV system.


Author(s):  
А.А. Кутузова ◽  
Д.М. Тебердиев ◽  
В.М. Косолапов ◽  
Л.С. Трофимова ◽  
А.В. Родионова ◽  
...  

Исследования проводили в ФНЦ «ВИК им. В. Р. Вильямса» на базе трёх долголетних полевых экспериментов: в опыте 1 изучали многоукосное использование ранних и среднеспелых злаковых травостоев в среднем за 28 лет (1993–2020 годы), в опыте 2 — люцерно-злаковые травостои для позднего звена укосного конвейера в среднем за 7 лет пользования (2013–2020 годы), в опыте 3 проведено сравнение четырёх технологических систем создания и использования травостоев за последние 28 лет (в среднем за 47–74-й годы пользования, 1993–2020 годы). Цель исследований — определение агроэнергетической эффективности 15 технологий по созданию усовершенствованных злаковых и бобово-злаковых травостоев, а также шести систем ведения долголетних сенокосов при производстве сырья для заготовки высококачественного сена и сенажа. Применение нового метода агроэнергетической оценки антропогенных затрат не только подтверждает высокую экономическую эффективность создания сеяных травостоев на лугах, но и впервые в конкретных (цифровых) показателях устанавливает роль разнообразных природных факторов. На долголетних злаковых травостоях (в течение 28 лет жизни трав) обеспечивается производство сырьевой массы для заготовки объёмистых кормов (сена и сенажа) первого и второго классов. Совокупные антропогенные затраты энергии на этих травостоях в среднем за 28 лет составили 16,3–17,1 ГДж/га при двухукосной и 23,2–23,6 ГДж/га — при трёхукосной технологии, на люцерно-злаковых травостоях при двух укосах в среднем за 7 лет — 5,2–5,8 ГДж/га. Затраты окупались сбором обменной энергии на ранних и среднеспелых агроценозах с доминированием корневищных злаковых видов в 2,8–3,3 раза, а на люцерно-злаковых травостоях — в 10,6–11,0 раз. В структуре производства обменной энергии основная её часть обеспечивалась за счёт возобновляемых природных факторов: 67–70% — на злаковых травостоях и 90% — на бобово-злаковых долголетних травостоях. The research took place at the Federal Williams Research Center of Fodder Production and Agroecology and consisted of three long-term field trials. The trial 1 was aimed at studying the multi-cut use of short- and mid-season gramineous for 28 years (1993–2020). The trial 2 tested alfalfa-gramineous swards for late cutting for 7 years (2013–2020). The trial 3 compared four technological systems of sward development and cultivation for the last 28 years (1993–2020). The aim of this research was to determine the energy efficiency of 15 cultivation technologies for optimization of gramineous and legume-gramineous swards as well as six systems of long-term hayfield cultivation to obtain high-quality hay and haylage. New method evaluating anthropogenic costs proved high economic efficiency of sown swards but also showed the impact of various natural factors. Long-term gramineous swards (28 years of life) provided raw material for bulk feed production (hay and haylage) of the first and second grade. For such swards total anthropogenic costs amounted to 16.3–17.1 GJ ha-1 under two cuts and 23.2–23.6 GJ ha-1 — under three cuts for 28 years. For alfalfa-gramineous swards total anthropogenic costs amounted to 5.2–5.8 GJ ha-1 for 7 years. The costs were paid back by 2.8–3.3 times through the exchange energy yield from short- and mid-season ecosystems with higher proportion of rootstock grasses, from alfalfa-gramineous swards — by 10.6–11.0 times. The great part of exchange energy was provided through renewable natural factors: 67–70% — from gramineous swards and 90% — from the legume-gramineous ones.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ahmed S Kagilik ◽  
Abduraouf M Tawel

Many Libyan authorities proposed to investigate the possibility of utilizing a suitable terrain in Libya to add generation capacity of large-scale photovoltaic power plants. In this paper, the first grid-connected PV plant of 14 MWp which will be executed in Hoon city and supported by the Renewable Energy Authority of Libya (REAOL) is presented. To understand and improve the operational behavior of PV system, a comprehensive study including the plant design and detailed performance analysis under a local climate conditions is performed. Using polycrystalline silicon technology, the first year energy yield is estimated and the monthly system output for this plant is calculated. The performance ratio and various power losses (temperature, irradiance, power electronics, interconnection, etc.) are determined. The PV system supplied 24964 MWh to the grid during the first year giving an average annual overall yield factor 1783 kWh/kWp and average annual performance ratio of the system of 76.9%.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ahmed S Kagilik ◽  
Abduraouf M Tawel

Many Libyan authorities proposed to investigate the possibility of utilizing a suitable terrain in Libya to add generation capacity of large-scale photovoltaic power plants. In this paper, the first grid-connected PV plant of 14 MWp which will be executed in Hoon city and supported by the Renewable Energy Authority of Libya (REAOL) is presented. To understand and improve the operational behavior of PV system, a comprehensive study including the plant design and detailed performance analysis under a local climate conditions is performed. Using polycrystalline silicon technology, the first year energy yield is estimated and the monthly system output for this plant is calculated. The performance ratio and various power losses (temperature, irradiance, power electronics, interconnection, etc.) are determined. The PV system supplied 24964 MWh to the grid during the first year giving an average annual overall yield factor 1783 kWh/kWp and average annual performance ratio of the system of 76.9%.


2021 ◽  
Vol 39 (4) ◽  
pp. 1158-1168
Author(s):  
H.O. Njoku ◽  
K.M. Ifediora ◽  
P.A. Ozor ◽  
J.M. Dzah

Soiling severely hinders the ability of solar photovoltaic (PV) modules to absorb incident solar radiation, causing significant  deterioration of module performances. In this study, the thermal profiles and the electrical power outputs of PV modules were  evaluated in order to establish the impact of soiling under tropical field conditions. Two case-study PV installations in the Universityof Nigeria were considered. Assessments of the PV systems, undertaken both when soiled and after they had been cleaned, involved the measurement of electrical power outputs and the acquisition of infrared (IR) thermograms. It was found that soiling had noticeable impacts on both module surface temperature distributions and their power outputs. The IR images, which showed spatial distributions of module surface temperatures, revealed the occurrence of hotspots on the modules when soiled. Furthermore, as a result of soiling, up to four-fold declines in module electrical efficiencies were observed. These declines were more significant in theground-mounted PV system at the University Staff Primary School compared to the roofmounted system at the University Energy  Research Centre. Simple cleaning of the modules led to the disappearance of hotspots and significant improvements in output, showing that it is an effective means of maintaining PV modules performance and recovering the performance potentials lost due to soiling. Keywords: solar PV, PV soiling, infrared thermography, module failure, PV performance


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3506 ◽  
Author(s):  
Diane Palmer ◽  
Elena Koumpli ◽  
Ian Cole ◽  
Ralph Gottschalg ◽  
Thomas Betts

Knowledge of roof geometry and physical features is essential for evaluation of the impact of multiple rooftop solar photovoltaic (PV) system installations on local electricity networks. The paper starts by listing current methods used and stating their strengths and weaknesses. No current method is capable of delivering accurate results with publicly available input data. Hence a different approach is developed, based on slope and aspect using aircraft-based Light Detection and Ranging (LiDAR) data, building footprint data, GIS (Geographical Information Systems) tools, and aerial photographs. It assesses each roof’s suitability for PV deployment. That is, the characteristics of each roof are examined for fitting of at least a minimum size solar power system. In this way the minimum potential solar yield for region or city may be obtained. Accuracy is determined by ground-truthing against a database of 886 household systems. This is the largest validation of a rooftop assessment method to date. The method is flexible with few prior assumptions. It can generate data for various PV scenarios and future analyses.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1310 ◽  
Author(s):  
Marcus Beck ◽  
Alexander Sperlich ◽  
Ricardo Blank ◽  
Eckehard Meyer ◽  
Ralf Binz ◽  
...  

Water collection based on groundwater abstraction has a high energy consumption that depends primarily on the operation and performance of submersible well pumps. The fact of the matter is that these machines still work with a global energy efficiency of less than 50%, and further investigations of the energy aspects in well pumps are needed. The present study introduces measures to increase the global efficiency of submersible well pumps linked to electrical energy savings. Common submersible pumps with asynchronous motors (ASMs) were compared with innovative permanent magnet synchronous motor (PMSM) technology in real well fields in Berlin and Hamburg waterworks. This study confirms that PMSM pumps showed a 6.8%-points higher global efficiency compared to ASM pumps at optimal working points. The investigation of the impact of well field operation on local pump efficiency offers an additional increase in the global efficiency. In this context, the influence of variable speed control on the global efficiency and the energy consumption was analyzed. Global efficiencies of over 70%, and potential energy savings of up to 20%, were determined for the speed-controlled PMSM pump. This offers water suppliers new incentives to optimize their water collection systems for less energy consumption.


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