Stand-alone Solar Energy Research Articles

Techno-economic assessment of green hydrogen production in unexploited landlocked northern-western region of Oman to realize national sustainable strategy

The sustainable and economical production of hydrogen is pivotal to the energy transition. This study assesses the techno-economic feasibility of green hydrogen in the unexploited northwest landlocked regions of Oman, capitalizing on unused renewable resources to facilitate a sustainable energy transition. In this study, a renewable energy system and green hydrogen production facility are sized to meet a fixed demand of hydrogen (100 metric tons per day) across five potential areas. Technical and economic metrics are then evaluated for various renewable energy combinations. The results reveal the lowest levelized cost of hydrogen in a standalone solar energy scenario, ranging from $8.34 to $16.73 per kilogram of hydrogen. Additionally, the levelized cost is projected and benchmarked against internationally reported values by IEA and IRENA, offering insights into the system's economics and guiding advancements in technology and policy. Further, the produced green hydrogen is anticipated to play a pivotal role in decarbonizing the nearby petroleum fields, small and medium enterprises, and domestic infrastructure. Consequently, this research aligns with Oman Vision 2040 and contributes to Oman's National Net-Zero Strategy 2050, as well as United Nations Sustainable Development Goal 7 (affordable and clean energy) and 12 (responsible consumption and production).

A New Multilevel Inverter With Reduced Component Count for a Standalone Solar Energy Conversion System

A New Multilevel Inverter With Reduced Component Count for a Standalone Solar Energy Conversion System

Fuzzy Logic Controller Based Perturb and Observe Maximum Power Point Tracking

This paper presents a fuzzy logic controller (FLC) based technique to design an adaptive perturb and observe (P&O) maximum power point tracking (MPPT) controller. The objective is to improve the efficiency of a standalone solar energy system consisting of a photovoltaic (PV) panel and a DC/DC buck converter connected to a variable load. The proposed FLC based technique is implemented on a TMS320F28335 DSP board and compared to the conventional P&O technique. The performance of the proposed system is validated through outdoor experiments with a 150-Watt PV system

Enhancing the Efficiency and Reliability of a Standalone Solar Energy System for Homes in Iraq

This study explores the knowledge regarding unconnected solar energy systems, their configurations, and the effects of Iraq's warm weather. Furthermore, it investigates the advantages and disadvantages of implementing such systems in Iraq. The research recognizes the efficacy of off-grid solar energy systems and their potential to provide clean electrical energy to meet the needs of Iraqi citizens while reducing harmful environmental emissions. The study employs an applied research project to assess the operational efficiency of off-grid solutions. The PVSYST application was used to simulate the solar energy system data. The research aims to develop off-grid solar energy systems, assess the suitability of building roofs, examine how heat affects panel productivity, and evaluate the impact of shading on energy levels, among other objectives. The study also covers the components of solar energy systems and how to assess their quality to withstand Iraq's typically hot climate.

(Invited) Solar Flow Batteries: Integrated Photoelectrochemical Solar Energy Conversion and Redox Flow Battery Systems

Due to the intermittent nature of sunlight, practical solar energy utilization systems demand both efficient solar energy conversion and inexpensive large scale energy storage. We have developed hybrid solar-charged storage devices called solar flow batteries (SFBs) that integrate photoelectrochemical solar cells with redox flow batteries (RFBs). In these devices, photoexcited carriers collected at the semiconductor-liquid electrolyte interface convert the redox couples to charge up the RFB without external electric bias; which can be discharged to generate the electricity when needed. By matching various silicon solar cells and tandem III-V solar cells (Chem 2018, 4, 2644) with various organic redox couples and optimizing the SFB device design, we improved their round trip solar-to-output electricity efficiency (SOEE) and eventually achieved a record SOEE of 20% with a 500-hour lifetime using high performance tandem perovskite/silicon solar cells (Nature Mater. 2020, 19, 1326). The design principles and the quantitative analysis model for voltage matching solar cells with RFBs (Acc. Chem. Res. 2020, 53, 2611) light up the pathways for achieving even better performance and stability yet maintaining a low cost, which would make these SFBs practical for standalone solar energy conversion and storage systems in remote off-grid locations.

Fuzzy Logic Control of Maximum Power Point Tracking Controller in an Autonomous Hybrid Power Generation System by Extended Kalman Filter for Battery State of Charge Estimation

Autonomous power generation systems are designed to operate independently from the public power grid. Batteries constitute the important element in stand-alone PV system. They are used to store electricity produced by solar energy at overnight or for emergency use during the non-constant load demand. This paper has three major parts.The first pertains the design of an intelligent method for maximum power point tracking based on fuzzy logic controller to improve the efficiency of a standalone solar energy system. The second part describes the battery state of charge (SOC). The proposed model, which better reflects the real SOC response of the lithium battery, is constructed by using the extended Kalman Filter (EKF) states estimator. This proposed method can be considered as a more accurate and reliable method to estimate the battery state of charge. The third part integrates a management system for the above two renewable energy sources. The performance of the proposed management system by using a fuzzy logic controller based maximum power point tracking FLC-MPPT and the EKF estimator have been simulated in Matlab/Simulink at different solar irradiation and temperature for a given no constant load energy request.

ENHANCE EFFICIENCY OF SOLAR ENERGY CONVERSION SYSTEM USING ANFIS WITH ISOLATED MODE

This paper shows performance investigation on enhance efficiency of standalone solar energy conversion system using ANFIS based MPPT controller. Now a days many researches are going in the field of renewable energy technologies to bridge the gap between supply and demand. Due to the Intermittent nature of renewable sources, operating standalone operation of them is highly unreliable causes interruption in power supply to the load. A solar photovoltaic system with MPPT based on Adaptive-Network-Based Fuzzy Inference System (ANFIS) is used for stable operation and to meet the supply with the load demand. The application of ANFIS based MPPT technique requires detailed study and analysis of the Solar Photovoltaic (SPV) system. Adaptive-Network-Based Fuzzy Inference System based MPPT technique is used along with Solar PV system as they can provide fast and accurate response to various environmental conditions. The Levenberg-Marquardt algorithm is used to train the neural network for MPPT in the photovoltaic system. This developed control strategy is able to control the devices and various power interface circuitry used therein. The main aim of this paper is to ensure a maximum power output coordinating appropriate control strategy with sources & compare the performance analysis of the ANFIS based MPPT with conventional incremental conductance based MPPT for the SPV system. The simulation studies have been carried out to find out the SPV system performance with different input conditions such as typical solar radiation and temperature. The Simulation test results show variable power generation and verifies that the performance of the integrated system with this control strategy is effective for the real-time installation. The simulation results shows that the performance of this developed control strategy for receiving maximum power output from the standalone SPV system is farfetched. Simulation test results show variable power generation and verify the performance of the integrated system with control strategy is overall effective for real-time installation. The developed system is essential in an isolated region where an existing grid is unable to supply secure power generation and system is beneficial with smartly feed ultimate power generation sources.

Development of Standalone Solar Energy Harvesting System with Cascaded H-Bridge Sub-multilevel Inverter

Development of Standalone Solar Energy Harvesting System with Cascaded H-Bridge Sub-multilevel Inverter

ARTIFICIAL INTELLIGENCE TECHNIQUE BASED MPPT CONTROLLER FOR STANDALONE SOLAR ENERGY CONVERSION SYSTEM

This paper presents the development and performance analysis of Artificial Intelligence Technique based MPPT controller for a standalone solar energy conversion system. The proposed system consists of 2.5 kW PV array, DC to DC boost converter, inverter and different load. The DC to DC Converter connected to Inverter through DC link capacitor. The inverter power fed to the load through step down transformer. The standalone solar energy conversion system consists of MPPT controller. In this research Artificial Intelligence Technique based MPPT controller on Levenberg algorithm developed. For the proposed Artificial Intelligence Technique based MPPT takes two variables as PV voltage and PV current as an input and output the duty ratio for DC to DC boost converter. The Artificial Intelligence Technique based MPPT controller for standalone solar energy conversion system with various load is modeled and simulated in MATLAB/ Simulink environment. Performance of both the Artificial Intelligence Technique based MPPT controller compared with conventional incremental conductance MPPT. Simulation results show that for a wide range of input irradiance, Artificial Intelligence Technique based MPPT controller shows improved performance than the conventional incremental conductance MPPT with at various operating conditions.

Fuzzy Based MPPT Controller For Solar Photovoltaic Systems

In this work, a Fuzzy Logic Control (FLC) based MPPT technique is proposed to improve the performance of a stand-alone solar energy system. The Fuzzy logic controller is used as an intelligent way of tracking the maximum power point (MPP). The Taguchi method is adopted in this study to analyze multiple operating conditions of solar PV array. Solar PV output changes with Atmospheric conditions. The change in PV Current and Power are measured and fed to the Fuzzy logic controller as input. The Fuzzy controller is designed with 25 fuzzy rules and the Mamdani fuzzy inference is performed to obtain the aggregation which will be defuzzified by Center of gravity method. Based on the change in PV Current and Power, the Fuzzy logic controller generate the duty cycle for the boost converter (DC-DC converter). The variation of the duty cycle is from 0 to 1. The signal of change in duty ratio from the Fuzzy logic MPPT algorithm is fed to the PWM for switching the IGBT to dynamically update the duty cycle of the boost converter for extracting the maximum power from the solar PV array. A stand-alone Photovoltaic system with a boost converter is simulated in MATLAB Simulink to demonstrate the results and applicability of the proposed method.

Challenges of small-scale standalone solar energy supply in parts of Lagos via 39 years dataset

The adoption of solar energy as a sustainable clean type of energy can be seen globally by the patronage of solar devices. However, the high patronage photovoltaic (PV) module by the small-scale standalone user may be mitigated by the recent high maintenance cost via PV module damages by UV radiation. This study analyzed thirty-nine years (1980-2018) shortwave dataset in the tropics to chart the way forward for PV user, manufacturer, and regulatory organizations. It was observed that there is an increase in shortwave radiation in recent times that has led to more damages to PV modules. However, there is a statistical possibility that there may be lower shortwave radiation in the next decade, thereby reducing PV module damage. It is recommended that PV manufacture should modify the PV polymeric to shield the PV modules from UV radiation damage. Based on this research’s finding, it is recommended that product regulatory organizations develop a new technique to monitor PV modules.

DESIGN AND SIZING OF STANDALONE SOLAR POWER GENERATION FOR A MEDIUM RESIDENCE IN KANO STATE

Energy is one of the prime mover of mankind and need of the energy is always increasing at the same time the sources of energy are depleting with respect to time. Because of these reasons, energy expert thinks of other sources of energy that are sustainable, among which solar energy is the freely renewable energy source and it is abundant in nature. This paper tend to design a stand-alone solar energy generation for a medium house in Kano state Nigeria, the results of the research revealed that a 300W solar PV array capacity of 30 modules, 22 (140Ah, 12V) batteries and 4 (90A, 202-253V) voltage regulator are needed to supply the electrical load of the house. The overall cost estimate of the system was ₦886,032 which is relatively high when compared to that of fossil fuel generator used by the house but the payback period of the system is estimated to be 2 years 4 months, which is obviously much shorter than the lifespan of the selected PV modules which is 30 years.

Techno-economic study of hybrid renewable energy system of Metropolitan Cities in India

ABSTRACT This paper proposes a Technical and Cost-Effective Analysis of Hybrid Renewable Energy System (HRES) in Metropolitan Cities in India using a Hybrid Optimisation Model for Electric Renewable (HOMER). In the current situation, standalone Solar Energy Conversion and Wind energy Conversion together or separate schemes have been supported around the region on a comparatively larger scale. These balanced systems cannot make available unbroken source of energy, as they are cyclic. Consequently, energy back-up systems could be necessary of those structures to satisfy the user load demands for every time. Typically storage devices or equipment are highly priced and the dimensions have to be reduced to a minimal viable for the renewable Energy System to be cost-effective. The hybrid power system can be used to reduce electricity garage necessities. A HRES mixes the time of strength through the Sun and wind energy conversion system.

(Invited) Designing Efficient Photoelectrochemical Solar Energy Conversion Devices and Their Integration with Redox Flow Battery Devices

Due to the intermittent nature of sunlight, practical solar energy utilization systems demand both efficient solar energy conversion and inexpensive large scale energy storage. We will first discuss the rational design and demonstration of efficient photoelectrochemical hydrogen generation systems using efficient semiconductors and earth-abundant catalyst materials. We have further developed novel hybrid solar-charged storage devices that integrate regenerative photoelectrochemical solar cells and redox flow batteries (RFBs) that share the same pair of redox couples. In these integrated solar flow batteries (SFBs), solar energy is absorbed by semiconductor electrodes and photoexcited caries are collected at the semiconductor-liquid electrolyte interface and used to convert the redox couples in the RFB to fully charge up the battery. When electricity is needed, the charged up redox couples will be discharged on carbon electrodes to generate the electricity as in a RFB. We have demonstrated that such SFB devices can be charged under solar light without external electric bias and deliver a high discharge capacity comparable with state-of-the-art RFBs over many cycles. After developing silicon solar cells and high performance solar cells, carefully matching them with various organic or inorganic redox couples, and optimizing several generations of SFB device designs, we have recently achieved integrated SFB device with an overall direct solar-to-output electricity efficiency (SOEE) of 14%. These high performance SFBs can serve as distributed and standalone solar energy conversion and storage systems in remote locations and enable practical off-gird electrification.

Graphene-Based Standalone Solar Energy Converter for Water Desalination and Purification.

Harvesting solar energy for desalination and sewage treatment has been considered as a promising solution to produce clean water. However, state-of-the-art technologies often require optical concentrators and complicated systems with multiple components, leading to poor efficiency and high cost. Here, we demonstrate an extremely simple and standalone solar energy converter consisting of only an as-prepared 3D cross-linked honeycomb graphene foam material without any other supporting components. This simple all-in-one material can act as an ideal solar thermal converter capable of capturing and converting sunlight into heat, which in turn can distill water from various water sources into steam and produce purified water under ambient conditions and low solar flux with very high efficiency. High specific water production rate of 2.6 kg h-1 m-2 g-1 was achieved with near ∼87% under 1 sun intensity and >80% efficiency even under ambient sunlight (<1 sun). This scalable sheet-like material was used to obtain pure drinkable water from both seawater and sewage water under ambient conditions. Our results demonstrate a competent monolithic material platform providing a paradigm change in water purification by using a simple, point of use, reusable, and low-cost solar thermal water purification system for a variety of environmental conditions.

Solar pv fed stand-alone excitation system of a synchronous machine for reactive power generation

This paper presents a model of a stand-alone solar energy conversion system based on synchronous machine working as a synchronous condenser in overexcited state. The proposed model consists of a Synchronous Condenser, a DC/DC boost converter whose output is fed to the field of the SC. The boost converter is supplied by the modelled solar panel and a day time variable irradiance is fed to the panel during the simulation time. The model also has one alternate source of rechargeable batteries for the time when irradiance falls below a threshold value. Also the excess power produced when there is ample irradiance is divided in two parts and one is fed to the boost converter while other is utilized to recharge the batteries. A simulation is done in MATLAB-SIMULINK and the obtained results show the utility of such modelling for supplying reactive power is feasible.

PEM fuel cell degradation effects on the performance of a stand-alone solar energy system

After comparing fresh and degraded performances of Polymer Electrolyte Membrane (PEM) based components of a hydrogen cycle with the help of computational fluid dynamics simulations, recently established stand-alone solar energy system producing hydrogen for energy storage is investigated focusing on the effects of degradation of fuel cells on the overall performance of the system. A complete model of the system has been developed using TRNSYS, and a degraded PEM Fuel Cell Subsystem has been incorporated into the model. Then, the effects of the PEM fuel cell degradation on the overall performance of the energy system are estimated. After reviewing the simulation results, the model shows that the PEM Fuel Cell degradation has a substantial impact on the overall system performance causing a system down time of approximately one month in a typical simulation year. Consequently, the stand-alone system is not capable of operating continuously for a complete year when the PEM fuel cells are degraded. Furthermore, an economic analysis is performed for a project lifetime of 25 years and the Levelized Cost of Electricity (LCE) value of the degraded system is found to be 0.08 $/kWh higher than the newly established system. Nevertheless, LCE calculations that are repeated for declining PV panel costs show that the considered hybrid system may be an economically competitive alternative to conventional diesel generators, even when the degradation of PEM based components and their regular maintenance are considered.

A maximum power point tracking scheme for a 1kw stand-alone solar energy based power supply

This paper elucidates one of the tracking schemes for a photovoltaic (PV) systems using Cuk converter operating in discontinuous inductor current mode (DICM) as an interface. A method for efficiently maximizing the output power of a solar panel supplying a load or battery bus under varying meteorological conditions is investigated and results presented therein. The incremental conductance (InCond) method of maximum power point tracking (MPPT) using the Cuks dc to dc converter operating in a discontinuous inductor current mode (DICM) was modeled and studied in relation to PV system interface. Also, laboratory setup was implemented based on the model. This was the main objective of the research. Similarly, the PV simulator was also modeled alongside with Cuk converter operating in DICM. MATLAB/SIMULINK software was used to carry out simulation test. With the incremental conductance method, the problem of sustained oscillation around the maximum power point of the solar panel which is the usual characteristic of the perturbation and observation method is essentially absent. The result disclosed that the power available for the load when MPPT was applied was 1.1 kW which gives a tolerance of 0.1% to the load it powers. But without MPPT, the available power is 0.9 kW using the same number of PV panels and batteries as back up. Hence, MPPT has 17.65% edge in power delivery over non-MPPT PV powered energy supply. An experimental prototype of a 1kW, 230V, 50Hz stand-alone solar based power supply with the incremental conductance scheme was successfully implemented using PIC 16F877 microcontroller, tested and results presented therein. The experimental results agreed with the simulated results. Keywords : Maximum Power point tracking, Cuk converter, Photovoltaic system, PIC 16F877A micro-controller, inverter, batteries.

A Novel Method for Fast Configuration of Energy Storage Capacity in Stand-Alone and Grid-Connected Wind Energy Systems

In this paper, a novel method is proposed and applied to quickly calculate the capacity of energy storage for stand-alone and grid-connected wind energy systems, according to the discrete Fourier transform theory. Based on practical wind resource data and power data, which are derived from the American Wind Energy Technology Center and HOMER software separately, the energy storage capacity of a stand-alone wind energy system is investigated and calculated. Moreover, by applying the practical wind power data from a wind farm in Fujian Province, the energy storage capacity for a grid-connected wind system is discussed in this paper. This method can also be applied to determine the storage capacity of a stand-alone solar energy system with practical photovoltaic power data.

20804 自立エネルギーシステムの試み : 日常も使用可能な非常時用太陽光発電システムの開発

20804 自立エネルギーシステムの試み : 日常も使用可能な非常時用太陽光発電システムの開発