PV-Wind Hybrid System Research Articles

Performance of a PV–wind hybrid system for hydrogen production

This paper describes the performance of an integrated PV–wind hydrogen energy production system. The system consists of photovoltaic array, wind turbine, PEM electrolyser, battery bank, hydrogen storage tank, and an automatic control system for battery charging and discharging conditions. The system produced 130–140 ml/min of hydrogen, for an average global solar radiation and wind speed ranging between 200 and 800 W/m 2 and 2.0 and 5.0 m/s respectively. A mathematical model for each component in the system was developed and compared to the experimental results.

Design and techno-economical optimization for hybrid PV/wind system under various meteorological conditions

The optimal design of the renewable energy system can significantly improve the economical and technical performance of power supply. In this paper, the technical-economic optimization study of a stand-alone hybrid PV/wind system (HPWS) in Corsica Island is presented. Therefore, the primary objective of this study is to estimate the appropriate dimensions of a stand-alone HPWS that guarantee the energy autonomy of a typical remote consumer with the lowest levelised cost of energy (LCE). A secondary aim is to compare the performance and the optimal sizing of two system configurations. Finally, to study the impact of the renewable energy potential quality on the system size, the optimum dimensions of system are defined for five sites in Corsica Island. In this context, a complete sizing model is developed, able to predict the optimum system configuration on the basis of LCE. Accordingly, an integrated energy balance analysis is carried out for the whole time period investigated. The simulation results indicate that the hybrid system is the best option for all the sites considered in this study, yielding lower LCE. Thus, it provides higher system performance than PV or wind systems alone. The choice of the system configuration type affects the state of charge variation profile, especially at low wind potential sites, while the system size and the LCE are significantly influenced. It is shown that the LCE depends largely on the renewable energy potential quality. At high wind potential site, more than 40% of the total production energy is provided by the wind generator, while at low wind potential sites, less than 20% of total production energy is generated by the wind generator.

Sizing of photovoltaic systems: a review

Artificial intelligence (AI) techniques are becoming useful as alternate approaches to conventional techniques or as components of integrated systems. They have been used to solve complicated practical problems in various areas and are becoming popular more and more nowadays. AI techniques have the following features: can learn from examples; are fault tolerant in the sense that they are able to handle noise and incomplete data; are able to deal with non-linear problems; and once trained can perform prediction and generalization at high speed. AI-based systems are being developed and deployed worldwide in a myriad of applications, mainly because of their symbolic reasoning, flexibility and explanation capabilities. AI have been used and applied in different sectors, such as engineering, economic, medicine, military, marine, etc. They have also been applied for modelling, identification, optimization, prediction, forecasting, and control of complex systems. The main objective of this paper is to present an overview of the alternative approach and AI techniques for sizing of photovoltaic (PV) systems: stand-alone PV, grid-connected PV system, PV-wind hybrid system, etc). Published literature works presented in this paper show the potential of AI as a design tool in the optimal sizing of PV systems. Additionally the advantage of using an AIbased sizing of PV systems is that it provides good optimisation, especially in isolated areas, where the weather data are not always available.

Optimization of a Wind/PV Hybrid Power Generation System

This study investigates the wind and solar electricity generation availability at the Solar Energy Institute of Ege University, Izmir, Turkey. The main purpose of this study is to design an appropriate wind-PV hybrid system to cover the electricity consumption of the Institute. In order to do this, monthly average solar irradiation and wind speed data are used, which were measured, consisting of hourly records over an eight-year period from 1995–2002. Simple models were developed to determine wind, solar, and hybrid power resources per unit area. Correlations between the solar and wind power data were carried out on an hourly, daily, and monthly basis. It is shown that the hybrid system can be applied for the efficient and economic utilization of these resources.

Design, simulation and economic analysis of a stand-alone reverse osmosis desalination unit powered by wind turbines and photovoltaics

The fresh water shortage is a significant problem in many areas of the world such as deserts, rural areas, Mediterranean countries and islands. However, renewable energy potential in these areas is usually high using solar and wind energy. A desalination unit powered by renewable energy sources is a promising solution for this problem. This paper presents the design of a stand-alone hybrid wind-PV system to power a seawater reverse osmosis desalination unit, with energy recovery using a simplified spreadsheet model. A daily and monthly simulation and economic analysis were also performed. The calculated fresh water production cost was 5.2 ϵ/m 3, and the realized energy saving was up to 48% when a pressure-exchanger-type energy recovery unit is considered.

Techno-economic analysis of autonomous PV-wind hybrid energy systems using different sizing methods

The sizing and techno-economic optimisation of an autonomous PV-wind hybrid energy system with battery storage is addressed in this article. A novel sizing method is introduced. It is a developed version of similar earlier sizing methods, taking into account a further design parameter. The techno-economic optimisation of autonomous energy systems should include the following design parameters at the same time: the level of autonomy, i.e. the fraction of time for which the specified load can be met, and the cost of the system. Without one of these, the techno-economic optimisation would be incomplete. New concepts, which combine the system autonomy and cost, are also introduced to be used in the techno-economic optimisation process. The sizing of a PV-wind hybrid system on a yearly basis requires a detailed analysis of the solar radiation and wind speed on a monthly basis. It is common to size such renewable systems for the worst month. It is, however, shown that the worst month scenarios lead to too costly and, therefore, non-optimal a system in terms of techno-economics. It is, therefore, suggested that alternative solutions be sought, rather than using the worst month scenario. An alternative method is applied in the present article. It suggests a third energy source (auxiliary source) be incorporated into the system instead of increasing the hardware sizes excessively for the worst month. It is shown that this leads to techno-economically more optimum systems.

A simplified model based on clearness index for estimating yearly performance of hybrid PV energy systems

AbstractA simplified model for estimating the energy contribution of PV converter in a hybrid PV–wind system is presented. The simplified model determines the yearly solar fraction, that is the fraction of energy demand provided by PV, and the remaining loss of load (LOL) is assumed to be provided by wind turbines. The novel model is based on simulation results derived from 8 years of measured hour‐by‐hour solar irradiation data from five different locations in the world. The system performance is simulated by the PV–wind energy simulation program of the Cardiff School of Engineering (ARES). An hourly constant load profile is assumed.The performance of a PV system is primarily dependent on the solar irradiation distribution in a given location for the period of time in question. The new model correlates the location dependence observed in the yearly solar fraction curves of different data sets with one of the most characteristic solar irradiation distribution parameters, the yearly clearness index of the respective solar irradiation data. The new model requires the yearly clearness index value, which is commonly available for most locations throughout the world, as input. As the novel model is validated with solar irradiation data from different locations in the world, it could be used for predicting the solar fraction in a hybrid PV system with a very high level of accuracy, for a wide range of climates. Copyright © 2002 John Wiley & Sons, Ltd.

PHOEBUS—an autonomous supply system with renewable energy: six years of operational experience and advanced concepts

The PHOEBUS demonstration plant has been supplying the Central Library of Forschungszentrum Jülich (FZJ) with solar-generated electric energy all year round and independent of the public grid since 1993. The central task was to test the required storage using hydrogen as the energy carrier in conjunction with an electrolyser and a fuel cell under realistic irradiance and consumption conditions and to demonstrate the feasibility of such a zero-emission supply system. The general objective was to determine weak points from the operating experience and measured data obtained, to model the system in a component-oriented manner for simulation, to energetically optimize the plant, to achieve high operational reliability and, above all, to propose and implement cost-reducing and advanced system modifications. With the aid of validated simulation programs, it was possible to carry out optimization analyses for plant operation (annual scenarios) and plant configuration. Two advanced concepts were developed: PHOEBUS-2, a simplified system with reduced energy losses, and PHOEBUS-3, a wind–PV hybrid system supplying both electricity and heat. The advanced concepts PHOEBUS-2 and PHOEBUS-3 are the theoretical basis for applications such as a solar home system, a solar village, a scientific polar station or a storage module for grid-connected operation that can be realized in the near future.

Performance of different types of renewable power supply systems

SYNOPSIS A combination of different types of generator has proved useful on technical and economic levels. In this paper we investigate the performance of a hybrid Photovoltaic(PV)-Wind generator power supply system operating under good and fair insolation and wind regimes. The effectiveness of such a hybrid system is measured by the Relative Sizing Parameter (RSP), Money Saving Parameter (MSP), and the Overall Reliability Parameter (ORP). Under specified weather conditions and for a nominal load demand, the RSP relates the product of the PV-modules and storage batteries involved in sizing the PV-Wind hybrid system to those of a stand alone PV-system sized to meet the same load. The MSP reports the difference between the total costs of a stand-alone PV power supply system and a hybrid PV-Wind power supply system, both sized to meet the same load, as a percentage of the total costs involved in supplying the load with a stand-alone PV power supply system only. The ORP compares the yearly average of the daily excess energy (positive difference between generated and consumed energy) of the hybrid system to that of the stand-alone PV power system. Based on this strategy we were able to develop a number of design diagrams which can be used in judging the benefits of utilizing hybrid PV-Wind generators on both economic and energy reliability grounds.