•Parameters extraction of five electrical models with Levenberg Marquardt algorithm.•Comparison of approach results with those reported in literature.•Parameters of five electrical models are ...estimated and their accuracy are compared.•Higher relative error between calculated and measured energy is about 14%.
In this study, a new theoretical approach offering a good prediction of the performance of photovoltaic modules/strings/arrays was developed. The approach implemented in the Matlab/Simulink environment, is based on Levenberg Marquardt (LM) algorithm and was used to estimate the parameters of five electrical models selected among the most used ones. First the problem of initial guess is considered. For parameters initial values, an analysis of six was performed and lead to the choice of the group which offers the best trade-off between accuracy and speed of calculation. To validate the effectiveness of the proposed approach, the five-parameter model (L5P) is used for a comparison with both a deterministic method and two heuristics methods. The results clearly show that, the accuracy achieved with LM method is comparable to the deterministic one, but higher than that of the heuristics methods. Furthermore, the five selected electrical models have been evaluated on four different PV modules technologies. The I–V characteristic curves obtained under Standard Test Conditions (STC) by each of them, are compared to the manufacturer data. It was shown that, when the LM algorithm is used, the fives electrical models predict the behavior of the photovoltaic silicon modules with close accuracy. The best trade-off is achieved with L5P model. This result is confirmed by the theoretical estimation of solar energy production performed for three real power plants by using the fives models. The maximum difference between calculated and measured energy is around 14%.
This paper assesses the energy security performance of the electricity sectors of the West African Economic and Monetary Union (UEMOA) countries using Multiple-criteria Decision Analysis. First, it ...establishes a five-level framework incorporating the dimensions: availability and diversity; affordability and equality; efficiency and reliability; regulation and governance; and environmental sustainability to conceptualize energy security. 18 metrics characterizing these dimensions are then used to assess the energy security performance of the UEMOA countries during the 2010–2019 period. The results indicate that Côte d'Ivoire was the most secure country of the Union, followed by Senegal and Togo in 2019, while the worst-performing country was Niger. Furthermore, Mali, Benin and Niger were found to have regressed the most concerning energy security from 2010 to 2019, whereas Senegal had improved greatest, followed by Togo, Cote d’Ivoire and Burkina Faso. In addition, none of the countries were found to perform well in all the indicators of energy security. Therefore, common actions such as improving governance, increasing generation capacity with priority to renewable sources, improving energy efficiency, upgrading power systems and encouraging R&D and paying more attention to environmental concerns could enhance energy security throughout the electricity sectors of all the UEMOA countries.
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•A five-dimension framework correlated to 18 metrics is proposed.•Use is made of the MCDA methods to assess energy security (ES) in the UEMOA.•The Côte d'Ivoire and Niger emerged as the most and least secure countries.•Senegal progressed the most and Mali regressed the most in terms of ES.•No country performed well in all ES indicators, suggesting policy implications.
Agrivoltaic systems, which consist of the combination of energy production by means of photovoltaic systems and agricultural production in the same area, have emerged as a promising solution to the ...constraints related to the reduction in cultivated areas due to solar panels used in agricultural production systems. They also enable optimization of land use and reduction in conflicts over land access, in order to meet the increasing demand for agricultural products and energy resulting from rapid population growth. However, the selected installation configurations, such as elevation, spacing, tilt, and choice of panel technology used, can have a negative impact on agricultural and/or energy production. Thus, this paper addresses the need for a review that provides a clear explanation of agrivoltaics, including the factors that impact agricultural and energy production in agrivoltaic systems, types of panel configurations and technologies to optimize these systems, and a synthesis of modelling studies which have already been conducted in this area. Several studies have been carried out in this field to find the appropriate mounting height and spacing of the solar panels that optimize crop yields, as this later can be reduced by the shade created with the solar panels on the plants. It was reported that yields have been reduced by 62% to 3% for more than 80% of the tested crops. To this end, an optimization model can be developed to determine the optimal elevation, spacing, and tilt angle of the solar panels. This model would take into account factors that influence crop growth and yield, as well as factors that affect the performance of the photovoltaic system, with the goal of maximizing both crop yield and energy production.
Abstract
This work aims to determine the Energy Payback Time (EPBT) of a 33.7 MWp grid-connected photovoltaic (PV) power plant in Zagtouli (Burkina Faso) and assess its environmental impacts using ...the life cycle assessment tool according to ISO 14040 and 14044 standards. A “cradle to grave” approach was used, considering 1 kWh of electricity produced and injected into the national grid over 25 years as a functional unit. In addition to the baseline scenario, the other simulated scenarios combining three variables, module technology (mono c-Si, poly c-Si, and CdTe), type of mounting structure (aluminum and steel), and end-of-life treatments (landfill and recycling) were considered. SimaPro 9.4 software and the ReCiPe 2016 Midpoint (H) evaluation method were used for the calculations considering four environmental indicators. A sensitivity analysis of the change in the electricity mix was also performed. Results showed that the EPBT of the scenarios varies between 1.47 and 1.95 years, with the shortest and longest corresponding to scenarios 4 (CdTe modules, steel mounting structure, and recycling as end-of-life treatment) and scenario 3 (mono c-Si modules, aluminum mounting structure, and recycling as end-of-life treatment), respectively. All the EPBT scenarios studied can be considered acceptable given the long lifetime of PV systems (25 years). The following environmental impact results were obtained: climate change 37–48 CO
2
-eq kWh
-1
, freshwater ecotoxicity 4–11 g 1,4-DCB kWh
-1
, mineral resource scarcity 0.4–0.7 g Cu-eq kWh
-1
and 11–13 g oil-eq kWh
-1
for fossil resource scarcity. Scenario 3 (mono c-Si modules, aluminum mounting structure, and recycling as end-of-life treatment) dominates all environmental indicators studied except freshwater ecotoxicity, which is dominated by scenario 4 (CdTe modules, steel mounting structure, and recycling as end-of-life treatment). The sensitivity analysis showed that the change in the electricity mix could reduce around 30% the EPBT, climate change, and fossil resource scarcity. Considering the environmental indicators studied, using CdTe modules manufactured in a country with a less carbon-intensive electricity mix, using galvanized steel as the mounting structure, and completely recycling components at the end of their lifetime is the most environmentally friendly scenario. However, particular attention needs to be paid to the land occupation that this plant could generate.
This paper presents a performance comparison study performed on four photovoltaic modules. Three silicon technologies are concerned: one monocrystalline module, two polycrystalline modules and one ...module of tandem structure (amorphous/microcrystalline) also known as micromorph module. The modules I–V data and meteorological data have been measured during one year using an outdoor monitoring test facility named “IV bench”. This set up is installed at Ouagadougou (Latitude 12.45° North, Longitude 1.56° West) in Sudano Sahelian climate. The actual maximum power, the average performance ratios, the series resistances and the maximum power temperature coefficient of tested modules are determined from the outdoor measurements and used for comparison study. The power of all the modules has been stabilized in outdoor conditions before the performance analysis. The results show that the micromorph module presents the best performance on the selected site, with an average performance ratio of 92%. The monocrystalline and polycrystalline modules from the same manufacturer, have both an average performance ratio of 84%. The second polycrystalline module from another manufacturer, strangely presents the lowest average performance ratio (80%) due to both its large series resistance and the high maximum power temperature coefficient in operating conditions.
•Performances of three PV technologies are compared under sudano sahelian climate.•Many parameters are measured on the modules and analysed for the technology comparison.•Micromorph tandem cells, modules perform consistently better than c-Si on the site.•Series resistances' effects must be investigated when analysing module performances.
This paper addresses the energy consumption in conventional shea butter production processes and its impact on sustainability. The socio-cultural significance of shea butter extraction and the ...environmental challenges posed by the demand for firewood in the Shea belt are considered. The aim of this study is to review the existing research on energy consumption in conventional shea butter production processes and provide insights into reducing energy consumption while improving sustainability. The specific objectives are to analyse critical operations in the process and quantify their electricity, water, and heat demand. The study identifies grinding shea kernels into a paste, fat recovery, and oil clarification as the key operations regarding electricity, water, and heat demand, respectively. The conventional production process heavily relies on firewood as an energy source, consuming approximately 8–10 kWh of heat per kg of produced crude shea butter when improved cookstoves/roasters are used. However, the use of three-stone cookstoves can double or even quadruple the heat demand. Valorisation of shea butter process residues, such as kneading sludges, has the potential to cover 50% of the required heat and replace significant amounts of firewood. However, this approach necessitates careful process design and potentially alternative fuels from the residues to ensure efficient combustion and reduce smoke emissions. The conventional shea industry generates a considerable amount of by-products, yet no systematic and efficient valorisation scheme is currently implemented. By implementing improved cookstoves and developing a comprehensive valorisation strategy for process residues, significant reductions in energy consumption and environmental impact can be achieved.
•The model provides the best configuration to maximize crop yield and energy output.•The model gives the optimal height, spacing between tables, table size, and tilt.•The amount of solar irradiation ...available for crops under the panels are calculated.•The energy output and crop yield for each configuration of the system is evaluated.•The increase in crop yield is more sensitive to the expansion of panel row spacing.
The global population is experiencing rapid growth, leading to increased demand for energy and food resources, necessitating the expansion of cultivated land. The construction of photovoltaic power plants to meet energy needs may result in competition for land between the agriculture and energy sectors. To address this issue, agrivoltaics systems are perceived as a solution, allowing for the coexistence of agricultural and energy production in the same area. However, the shading caused by solar panels can potentially. Therefore, a model has been developed to determine the best configuration for maximising both crop yields and energy production from the photovoltaic field. The purpose of this paper is to develop a model that optimizes energy production and crop yield within an agrivoltaics system. The model integrates factors such as elevation, spacing, tilt, panel technology and size to enhance the radiation under the photovoltaic panels, as well as to increase crop yield and the efficiency of photovoltaic array. It is constructed based on the climatic condition and the relationship between the shaded area and the sunlight distribution below the photovoltaic panels. Furthermore, the model relies on the correlation between the configuration used and the energy power delivered by the photovoltaic array. A set of equations that link configuration, sunlight, crop yield, and photovoltaic panel power was developed, and the model was implemented in MATLAB, using genetic algorithm optimisation techniques. The initial step involves the determination of radiation values under the panels, followed by the identification of the best scenarios for subsequent simulations aimed at evaluating crop yield and power generation from the photovoltaic array. A case study was conducted in Kamboinsin village (12°27′ N, 1°33′ W), in Burkina Faso, focusing onusing corn cultivation to validate the model. The results show that the model effectively identifies the optimal configuration for maximizing both crop yield and photovoltaic field output. The simulation results reveals that the distribution of radiation under the panels is significantly influenced by factors such as panel elevation height, spacing between table, and spacing between rows of table. Notably, the yield is more sensitive to the spacing between rows of panels. When comparing the effects of the different panel sizes, it is evident that utilizing smaller tables leads to higher crop yields. However, this approach results in a decrease in energy production from the photovoltaic field. For instance, on 1 ha of land, a table consisting of a single 100 Wp panel generated 92.8 % of the crop yield achieved in full sun with a nominal power of 96.9 kWp, whereas a table comprising 2 panels of 260 Wp produced 80.1 % of the yield with a nominal power of 378.56 kWp.
•A large-scale, city-wide household electricity survey is conducted in Burkina Faso.•Use is made of the survey’s results to analyse the urban domestic electricity use.•2395 kWh is averagely used by ...households per year with cooling consuming the most.•Interaction between electricity use and household’s lifestyle is investigated.•Lack of knowledge on energy efficiency is noticed, suggesting policy implications.
Information on actual domestic electricity use in Burkina Faso, where the urban zones and residential sector account for 74% and 33% respectively of the total electricity use, remains very challenging to find, as little research currently exists. This study aimed therefore, to provide the first ever insights into the actual urban residential electricity use. A survey with 387 households, the first large-scale, city-wide household electricity study undertaken in Burkina Faso to the authors’ knowledge, was conducted in the city of Ouagadougou. Information on the households' characteristics and behaviours were collected to yield a first comprehensive analysis on the actual city-scale domestic electricity use. Findings demonstrated an average electricity use of 2395 kWh/year by households. Cooling accounts for almost 40% of the total domestic electricity use, followed mainly by cooking and food preserving (23%) and information-communication-entertainment (19%) activities. Three groups of consumers were then formed based on their electricity use level, to investigate interactions between electricity use and households’ lifestyles. The study’s findings lay therefore, the foundations for a better understanding of actual urban domestic electricity use patterns and could help to develop more suitable policies and actions targeting energy conservation in the residential sector.
In this work we present a study of the structural, optoelectronic and transport properties of a series of Si films deposited in a parameter region (namely hydrogen dilution) corresponding to a ...transition from amorphous-to-nanocrystalline silicon by hot-wire (HW) and radio-frequency plasma enhanced chemical vapor deposition (RF) on plastic substrates at 150°C. To achieve a higher deposition rate of Si films by RF we used a relatively high power density (350mW/cm2) and deposition pressure (1.5Torr). For certain hydrogen dilution values, these deposition conditions can lead to the formation of Si crystals in the silane plasma and to a growth of polymorphous silicon film. This material has improved carrier transport properties (ambipolar diffusion length=220nm) and very high photosensitivity (>5×106). The best HW amorphous silicon films exhibited lower photosensitivity (7×104) and an ambipolar diffusion length of only 100nm. For solar cell fabrication, we optimized the RF deposition conditions to produce very thin amorphous and nanocrystalline phosphorous and boron doped silicon layers. Our best n–i–p solar cell, with a polymorphous Si intrinsic layer deposited on plastic, has an efficiency of 5.5%, FF=52.5%, VOC=920mV, JSC=11.6mA/cm2. For solar cells with a nanocrystalline Si active layer deposited on glass the following results were achieved: efficiency=3.4%, FF=43.5%, VOC=460mV, JSC=17.2mA/cm2; and on plastic substrate: efficiency=2.2%, FF=32.7%, VOC=397mV, JSC=17.2mA/cm2.
