Publications

2024
Rahrah K, Taibi S, Bouzgou H. Optimizing Annual Energy Output of a Residential Bifacial PV System Using Box-Behnken Design: A Case Study in Tamanrasset, Algeria. In: Lecture Notes in Networks and Systems ((LNNS,volume 1238)) . Springer ; 2024. pp. 428-436. Publisher's VersionAbstract
In this paper, Response Surface Methodology (RSM) with optimization is proposed to determine the optimal annual energy output of a small-scale residential bifacial PV system, considering constraints input parameters such as albedo type, module height, tilt angle, and spacing. This could be done by quantifying the relationship between the variable input parameters and the corresponding output parameter where RSM is integrated with PVsyst simulation tool for the analysis. The proposed Box-Behnken design (BBD) optimization required 29 runs for data acquisition and modelling the response surface and Design-Expert software was used to design the experiments and randomize the runs. Regression model was developed and its adequacy was verified to predict the output value at nearly all conditions. The optimization study shows that the system produces the maximum yearly energy when the ground albedo is 0.71, module height is 1.68 m, tilt angle is 19.42°, and module spacing is 7.42 m. These characteristics were found using the meteorological conditions in Tamanrasset, Algeria.
Louchene HE, Bouzgou H, Gueymard C. Determination of the Optimal Volume and Distribution of Learning Data for Solar Irradiance Forecasting Applications. In: Lecture Notes in Networks and Systems ((LNNS,volume 1238)) . Springer ; 2024. pp. 584–593. Publisher's VersionAbstract
Given the significant importance of renewable or alternative energies today, extensive research is being conducted to enhance the efficiency and reduce the costs of utilizing these energy sources. Among these studies, solar energy forecasting plays a crucial role in achieving these objectives. Accurate forecasting can optimize energy yield, improve grid management, and facilitate the integration of solar power into existing energy systems, ultimately contributing to more reliable and cost-effective renewable energy solutions. This contribution investigates how data volume influences forecasting accuracy. In particular, the impacts on forecasting accuracy of varying forecast horizons and optimal data splitting for training and testing phases are examined. Additionally, the effects on forecasting Global Horizontal Irradiance (GHI) of clustering the data into 3, 5, or 7 groups using the K-means algorithm are investigated. Five different predictive models are employed— multi layer perceptron (MLP), support vector regression (SVR), random forest (RF), convolutional neural network (CNN), and long short-term memory (LSTM)— alongside the newly proposed kResCLSTM hybrid method. Using GHI observations at an arid site in southern Algeria, it is found that a 10-year time series is optimal, along with a 60%-40% split in it for the training vs. testing periods.
Megaache SE, Bouzgou H, Gama A, Zerari N. Spatiotemporal Prediction of Solar Irradiance in Algeria: A CNN-Driven Approach for Solar Energy Mapping. In: Lecture Notes in Networks and Systems ((LNNS,volume 1238)) . Springer ; 2024. pp. 544–553. Publisher's VersionAbstract
The first objective of this study is to estimate the potential of solar irradiance in Algeria using an artificial intelligence approach, namely, convolutional neural networks (CNNs). The second objective is to visualize the different solar components DNI, DHI, and GHI as spatial maps. Data from 267 locations for 2005–2022, obtained from the NREL database, subdivided into training and testing data are used to build the different forecasting models. Testing data are not used when training CNNs to provide an indication of the performance at unknown locations. CNN models with 9 input variables average temperature, relative humidity, sunshine duration, wind speed, precipitation, longitude, latitude, altitude, and month were used to estimate the monthly values of GHI, DNI, and DHI. Statistical error analysis is conducted using mean absolute error (MAE), Mean Absolute Percentage Error (MAPE), Mean Bias Error (MBE) and coefficient of determination R2. This study shows that CNNs can be a better solution to estimate solar irradiance data. Seasonal solar mapping was developed in a GIS environment, representing locations and values of solar irradiance. These maps offer valuable insights into solar energy resources, aiding in the implementation of solar energy systems.
zemouri N, Mezaache H, Bouzgou H. Comparative Analysis of Forecasting Methods for Renewable Energy Across Forecast Horizons. Algerian Journal of Renewable Energy and Sustainable Development [Internet]. 2024;06 (02) :231-240. Publisher's VersionAbstract
Sustainable energy sources like solar and wind speed provide an economically efficient source of energy. Prediction of the output of renewable energy plays a crucial role in shaping decisions concerning electrical system operation and management. Forecasting precision in renewable energy output is essential to ensuring the reliability and stability of the grid, as well as for mitigating risks and minimizing costs within the energy market and power systems. Various statistical techniques were developed to predict solar radiation and wind speed for this purpose and there are two types approaches commonly used: Deep learning and artificial Neural network (ANN). This work propose the used of three statistical methods based in Elman Recurrent Neural Network (ERNN), Long Short Term Memory (LSTM) and Support Vector Machine (SVM) to forecast the output data in different forecasting horizons. Four evaluation deferent metric are used: Forecast skill (FS), Root mean square error (RMSE), Mean Absolute Error (MAE) and coefficient of determination ( R2). These metrics confirm the robustness and accuracy of the LSTM model, validated by its RMSE, MAE, FS, and R² values for both sites. These performances demonstrate the effectiveness of LSTM in capturing temporal patterns, with significant implications for weather forecasting and renewable energy applications.
zemouri N, Mezaache H, Bouzgou H. A Set of Forecasting Methods to Predict Solar Irradiance and Wind Speed for Different Horizons, in Première Conférence Nationale (en ligne) sur les Applications de l'Intelligence Artificielle et le Développement Durable (1ère CNAIADD'2024). ; 2024.
2023
Zerari N, Gueymard C, Bouzgou H, Raymond C. Machine Learning Approach to Estimate Ultraviolet Irradiance from Solar Radiation Data, in 2023 International Conference on Electrical Engineering and Advanced Technology (ICEEAT). IEEE ; 2023 :1-6. Publisher's VersionAbstract
One primary cause of degradation for materials exposed to the outdoors is ultraviolet (UV) light. To estimate their rate of degradation and determine their longevity (service life), truthful quantification of the UV irradiation incident on their surfaces is needed. In this paper, several neural models are proposed to estimate three UV components based on the broadband global horizontal irradiance and various atmospheric constituents. Using spectral results obtained with the SMARTS model for a large variety of atmospheric conditions and sun positions, three groups of experiments are carried out: the first one is designed to estimate the total UV irradiance at the surface (280–400 nm), whereas the second and third groups aim at estimating its UV-A and UV-B fractions, respectively. The results generally show a good prediction performance, particularly for the first two groups.
2022
zemouri N, Bouzgou H, Chouder A, DOUAK M. Multi-Step Solar Power Forecasting using Deep Learning Methods, in International Conference of Advanced Technology in Electronic and Electrical Engineering (ICATEEE). ; 2022. Publisher's Version
2021
Zereg H, Bouzgou H. Multi-Objective Optimization of Stand-Alone Hybrid Renewable Energy System for Rural Electrification in Algeria, in IC-AIRES: International Conference on Artificial Intelligence in Renewable Energetic Systems. ; 2021.
Louchene HE, Bouzgou H, Gueymard CA. Residual Networks with Long Short Term Memory for Hourly Solar Radiation Forecasting, in IC-AIRES: International Conference on Artificial Intelligence in Renewable Energetic Systems. ; 2021.
zemouri N, Bouzgou H, Gueymard CA. Sample Entropy with One-Stage Variational Mode Decomposition for Hourly Solar Irradiance Forecasting, in International Conference on Renewable Energy Advanced Technologie and Applications (ICREATA'21). Adrar, Algeria ; 2021.
Atmani H, Bouzgou H, Gueymard CA. Deep Long Short-Term Memory with Separation Models for Direct Normal Irradiance Forecasting: Application to Tamanrasset, Algeria, in International Conference on Renewable Energy Advanced Technologie and Applications (ICREATA'21). Adrar, Algeria ; 2021.
Zereg H, Bouzgou H. Techno-Economic Analysis of a Stand-Alone Hybrid Renewable Energy System for Residentiel Electrification in Tamanrasset, Algeria, in International Conference on Renewable Energy Advanced Technologie and Applications (ICREATA'21). Adrar, Algeria ; 2021.
2020
zemouri N, Bouzgou H, Gueymard CA. Global Solar Radiation Forecasting With Evolutionary Autoregressive Models, in 4th International Conference on Artificial Intelligence in Renewable Energetic Systems (IC-AIRES'20). ; 2020.Abstract

Nowadays, the integration of solar power into the electrical grids is vital to increase energy efficiency and profitability. Effective usage of the instable solar production of photovoltaic (PV) systems necessitates trustworthy forecasting information. Actually, this addition can gives an ameliorated service quality if the solar radiation variation can be forecasted accurately. In this paper, we propose a new forecasting approach that integrates Autoregressive Moving Average (ARMA) and Genetic algorithms (GA) to make benefit of both of them in order to forecast Global Horizontal Irradiance (GHI) component. The proposed approach is compared with the standard ARMA model. The experimental results show that, the proposed approach outperforms the classical ARMA models in terms of mean absolute percentage error (MAPE), root mean squared error (RMSE) coefficient of determination (R)2 and the normalized mean squared error (NMSE).

2019
zemouri N, Bouzgou H, Gueymard CA. Multimodel ensemble approach for hourly global solar irradiation forecasting. The European Physical Journal Plus (Springer-Verlag) [Internet]. 2019;134 :594. Publisher's VersionAbstract
This contribution proposes a novel solar time series forecasting approach based on multimodel statistical ensembles to predict global horizontal irradiance (GHI) in short-term horizons (up to 1 hour ahead). The goal of the proposed methodology is to exploit the diversity of a set of dissimilar predictors with the  purpose of increasing the accuracy of the forecasting process. The performance of a specific multimodel ensemble forecast showing an improved forecast skill is demonstrated and compared to a variety of individual single models. The proposed system can be applied in two distinct ways. The first one incorporates the forecasts acquired from the different forecasting models constituting the ensemble via a linear combination (combination-based). The other one consists of a novel methodology that delivers as output the forecast provided by the specific model (involved in the ensemble) that delivers the maximum precision in the zone of the variable space connected with the considered GHI time series (selection-based approach). This forecasting model is issued from an appropriate division of the variable space. The efficiency of the proposed methodology has been evaluated using high-quality measurements carried out at 1min intervals at four radiometric sites representing widely different radiative climates (Arid, Temperate, Tropical, and High Albedo). The obtained results emphasize that, at all sites, the proposed multi-model ensemble is able to increase the accuracy of the forecasting process using the different combination approaches, with a significant performance improvement when using the classification strategy.
Zerari N, Abdelhamid S, Bouzgou H, Raymond C. Bidirectional deep architecture for Arabic speech recognition. Open Computer Science (De Gruyter) [Internet]. 2019;9 :92–102. Publisher's VersionAbstract
Nowadays, the real life constraints necessitates
controlling modern machines using human intervention
by means of sensorial organs. The voice is one of the human
senses that can control/monitor modern interfaces.
In this context, Automatic Speech Recognition is principally
used to convert natural voice into computer text as
well as to perform an action based on the instructions
given by the human. In this paper, we propose a general
framework for Arabic speech recognition that uses Long
Short-Term Memory (LSTM) and Neural Network (Multi-
Layer Perceptron: MLP) classifier to cope with the nonuniform
sequence length of the speech utterances issued
fromboth feature extraction techniques, (1)Mel Frequency
Cepstral Coefficients MFCC (static and dynamic features),
(2) the Filter Banks (FB) coefficients. The neural architecture
can recognize the isolated Arabic speech via classification
technique. The proposed system involves, first, extracting
pertinent features from the natural speech signal
using MFCC (static and dynamic features) and FB. Next,
the extracted features are padded in order to deal with the
non-uniformity of the sequences length. Then, a deep architecture
represented by a recurrent LSTM or GRU (Gated
Recurrent Unit) architectures are used to encode the sequences
ofMFCC/FB features as a fixed size vector that will
be introduced to a Multi-Layer Perceptron network (MLP)
to perform the classification (recognition). The proposed
system is assessed using two different databases, the first
one concerns the spoken digit recognition where a comparison
with other related works in the literature is performed,
whereas the second one contains the spoken TV
commands. The obtained results show the superiority of
the proposed approach.
Bouzgou H, Gueymard CA. Fast Short-Term Global Solar Irradiance Forecasting with Wrapper Mutual Information. Renewable Energy (Elsevier) [Internet]. 2019;133 :1055-1065. Publisher's VersionAbstract
Accurate solar irradiance forecasts are now key to successfully integrate the (variable) production from large solar energy systems into the electricity grid. This paper describes a wrapper forecasting methodology for irradiance time series that combines mutual information and an Extreme Learning Machine (ELM), with application to short forecast horizons between 5-min and 3-hour ahead. The method is referred to as Wrapper Mutual Information Methodology (WMIM). To evaluate the proposed approach, its performance is compared to that of three dimensionality reduction scenarios: full space (latest 50 variables), partial space (latest 5 variables), and the usual Principal Component Analysis (PCA). Based on measured irradiance data from two arid sites (Madina and Tamanrasset), the present results reveal that the reduction of the historical input space increases the forecasting performance of global solar radiation. In the case of Madina and forecast horizons from 5-min to 30-min ahead, the WMIM forecasts have a better coefficient of determination (R2 between 0.927 and 0.967) than those using the next best performing strategy, PCA (R2 between 0.921 and 0.959). The Mean Absolute Percentage Error (MAP) is also better for WMIM [7.4–10.77] than for PCA [8.4–11.55]. In the case of Tamanrasset and forecasting horizons from 1-hour to 3-hours ahead, the WMIM forecasts have an R2 between 0.883 and 0.957, slightly better than the next best performing strategy (PCA) (R2 between 0.873 and 0.910). The Normalized Mean Squared Error (NMSE) is similarly better for WMIM [0.048–0.128] than for PCA [0.105–0.130]. It is also found that the ELM technique is considerably more computationally efficient than the more conventional Multi Layer Perceptron (MLP). It is concluded that the proposed mutual information-based variable selection method has the potential to outperform various other proposed techniques in terms of prediction performance.
2018
Mezaache H, Bouzgou H. Auto-Encoder with Neural Networks for Wind Speed Forecasting, in International Conference on Communications and Electrical Engineering (ICCEE) . IEEE ; 2018 :1-5. Publisher's VersionAbstract
The use of wind energy is progressively utilized to produce electrical energy. Wind energy is related to the variation of some atmospheric variables such as wind direction, wind speed, air density and atmospheric pressure. Recently, numerous methods base on Artificial Intelligence techniques to forecast wind speed have been proposed in the literature. In this paper a new artificial intelligence approach for wind speed time series forecasting is proposed, it is composed from two blocs: The first one is based on the use of a deep architecture. The Autoencoder which is a type of deep neural networks, utilized generally for Denoising, is employed to reduce the wind speed input dimensionality. In the second bloc of the proposed methodology, the Elman neural network is employed to forecast future values of wind series, it is a kind of recurrent neural networks that are very sensitive to historical variations. To evaluate our approach we used the following error indicators: Root Mean Square Error (RMSE),Mean Absolute Bias Error (MABE), Mean Absolute Percentage Error (MAPE)and the coefficient of determination (R 2 ). The obtained results are compared with those of the Extreme Learning Machine method.
Zerari N, Abdelhamid S, Bouzgou H, Raymond C. Bi-directional recurrent end-to-end neural network classifier for spoken Arab digit recognition. 2nd International Conference on Natural Language and Speech Processing (ICNLSP) IEEE [Internet]. 2018 :1-6. Publisher's VersionAbstract
Automatic Speech Recognition can be considered as a transcription of spoken utterances into text which can be used to monitor/command a specific system. In this paper, we propose a general end-to-end approach to sequence learning that uses Long Short-Term Memory (LSTM) to deal with the non-uniform sequence length of the speech utterances. The neural architecture can recognize the Arabic spoken digit spelling of an isolated Arabic word using a classification methodology, with the aim to enable natural human-machine interaction. The proposed system consists to, first, extract the relevant features from the input speech signal using Mel Frequency Cepstral Coefficients (MFCC) and then these features are processed by a deep neural network able to deal with the non uniformity of the sequences length. A recurrent LSTM or GRU architecture is used to encode sequences of MFCC features as a fixed size vector that will feed a multilayer perceptron network to perform the classification. The whole neural network classifier is trained in an end-to-end manner. The proposed system outperforms by a large gap the previous published results on the same database.
2017
zemouri N, Bouzgou H. Ensemble of Support Vector Methods to Estimate Global Solar Radiation In Algeria. International Conference on Artificial Intelligence in Renewable Energetic Systems, IC-AIRES2017 (Springer) [Internet]. 2017 :1-5. Publisher's VersionAbstract
In this paper, we propose a set of times series forecasting techniques based on the combination of Support Vector Regression methods to predict global horizontal solar radiation in Algeria. The models were constructed and tested using different architectures of Support Vector Machine (SVM), namely, (RBF kernel, Polinomial kernel and Linear kernel). We use individual time series models and linear combination techniques to predict global solar radiation indifferent sites in Algeria. For this aim, the recorded data of 4 stations spread over Algeria were used to build different combination schemes for the different times series algorithms. The efficiency of the different models was calculated using a number of statistical indicators: the Mean Absolute Percentage Error (MAPE), the Mean Squared Error (RMSE), Mean Bias Error (MABE) and the Coefficient of Determination (R 2). The results obtained from these models were compared with the measured data.
Atmani H, Bouzgou H, Gueymard CA. Intra-hour Forecasting of Direct Normal Solar Irradiance using Variable Selection with Artificial Neural Networks. International Conference on Artificial Intelligence in Renewable Energetic Systems, IC-AIRES2017 (Springer) [Internet]. 2017 :1-5. Publisher's VersionAbstract
Renewable Energy Sources (RES) are one of the key solutions to handle the world’s future energy needs, while decreasing carbon emissions. To produce electricity, large concentrating solar power plants depend on Direct Normal Irradiance (DNI), which is rapidly variable under broken clouds conditions. To work at optimum capacity while maintaining stable grid conditions, such plants require accurate DNI forecasts for various time horizons. The main goal of this study is the forecasting of DNI over two short-term horizons: 15-min and 1-h. The proposed system is purely based on historical local data and Artificial Neural Networks (ANN). For this aim, 1-min solar irradiance measurements have been obtained from two sites in different climates. According to the forecast results, the coefficient of determination (R2) ranges between 0.500 and 0.851, the Mean Absolute Percentage Error (MAPE) between 0.500 and 0.851, the Normalized Mean Squared Error (NMSE) between 0.500 and 0.851, and the Root Mean Square Error (RMSE) between 0.065 kWh/m2 and 0.105 kWh/m2. The proposed forecasting models show a reasonably good forecasting capability, which is decisive for a good management of solar energy systems.

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