Analysis Of Solar Energy Systems Research Articles

A Reliability Study of Photovoltaics Energy Systems in DC Microgrid

In this paper, a lifetime of Photovoltaics PV is studied based on the evaluation of the reliability of the DC microgrid. The analysis has a comprehensive consideration of the elements of the inverter and converter composed of a renewable energy system and its process during bad weather as a supplementary measure for the intermittent output of renewable energy sources connected to the DC microgrid. A battery and a boost converter for the battery were used to keep the voltage constant. The output of the battery varies according to the output fluctuation of the renewable energy source. At this time, the life analysis result of the switching devices that are used in the boost converter is introduced. To prevent system downtime and increase maintenance costs due to converter failures connected to the battery, a converter life analysis is required. Considering that the main failure mechanism of switching devices used in converters is thermal stress, and power loss due to thermal stress. Based on the above, the lifetime characteristics of semiconductor devices are analyzed. The main contribution of this work is conducting the lifetime analysis of solar energy system that is used in the DC microgrid with different weather conditions

Solar Renewable Energy System (SRES) for an Educational Institute

This paper highlights a Solar energy generation plant as Renewable energy source (SRES) on the criterion of cost involvement using net present value (NPV) method and its payback period. The reliability of the system and economic considerations of SRES are analyzed in depth for an educational institute. This is an installed off-grid system which comprises a wind energy source of 1.5 kW and solar energy source of 6 kW. The present work is focused on cost and performance analysis of solar energy systems only. The SRES considered here is connected to the light load of the department containing all lights, fans, personal computers, printers and LCD display. The results obtained proves that SRES has the potential to fulfill the demand reliably throughout the year. The cost analysis using NPV method is included with the existing MAHADISCOM as one of the projects and SRES as another project. Both the projects are analyzed by assuming the lifespan of 11 years. The payback period of the SRES system is 3.3 years and hence after that the energy will be available free of cost through the mentioned system. This analysis is done for the site located in the state of Maharashtra, India, and can be used as very useful research for future perspectives.

Techno-economic analysis of solar energy system for electrification of rural school in Southern Ethiopia

To provide rural communities with low-cost electricity, innovative off-grid renewable energy producing techniques have emerged. The International Energy Agency estimates that around 45% of Ethiopia’s total population have access to electricity. Nearly 85% of Ethiopia’s urban population has access to public electricity, but this figure is only 29% for the rural population. This study examines the feasibility of using combined photovoltaic (PV)/diesel/battery systems to power a remote rural school in southern Ethiopia. The performance of various hybrid systems was assessed using techno-economic and environmental analyses, and the optimal solution was chosen using the Hybrid Optimization Model for Electric Renewable (HOMER) analytic tool. The evaluation criteria include net present cost (NPC), cost of energy (COE) and emissions. The results indicate that PV/DG/battery hybrid energy system (HES) with a 7.5 kW PV, 7.3 kW DG, 6.60 kW converter, and 11 units of batteries (case I) is the most feasible, optimized, cost-effective and environmentally friendly system among the systems considered. This system has a Net Present Cost (NPC) of $32,019 and a Cost of Energy (COE) of $0.254/kWh, as computed using current equipment values. The optimized system is also environmentally benign, emitting 793 kg of carbon dioxide per year, about 91% less than the PV/diesel combination (worst case IV). Furthermore, sensitivity analysis was performed to examine the impacts of altering factors such as solar radiation, fuel price, and battery minimum state of charge (SOCmin) on system cost and performance. We believe that the information given in this paper will shed light on the current state and future prospects for renewable energy deployment in Ethiopia, and also show that, if policymakers create the necessary investment environment, such projects can be a viable alternative to rural electrification.

Performance Analysis of Solar Energy System with Bidirectional Convertersand Using Fuzzy Inference Based Modified Inertia PSO Technique

Performance Analysis of Solar Energy System with Bidirectional Convertersand Using Fuzzy Inference Based Modified Inertia PSO Technique

Empirical model development for the estimation of clearness index usingmeteorological parameters

The clearness index is an indispensable parameter required for the design and analysis of solar energy systems. In the absence of measured values for a specific location, the clearness index can be estimated from other measured meteorological variables. In this study three meteorological parameters, sunshine hours, monthly mean values of the temperature difference ($\Delta$T), and cloudiness, are used to develop empirical models for the estimation of clearness index. The empirical models are developed for five major cities in Pakistan (Karachi, Multan, Lahore, Islamabad, and Quetta). For empirical model development, long-term data (1991 to 2010) of monthly average clearness index, sunshine hours, average daily minimum and maximum temperatures, and cloudiness have been used. The accuracy of the models has been tested by statistical indicators that include mean percentage error (MPE), coefficient of determination (R$^2$), mean absolute relative error (MARE), mean bias error (MBE), and root mean square error (RMSE). The error analysis revealed that the proposed models are suitable for the estimation of the clearness index. It is also concluded that multiple regression models give better estimates of clearness index for all the stations (0.80 $\leq$ R$^{2}$ $\leq$ 0.86) compared to single parameter model and therefore are recommended. The study indicated that clear sky conditions prevail throughout the months at all the investigated sites (0.58 $\leq$ K$_T$ $\leq$ 0.68), which is a good indicator for solar energy utilization. The statistical indicators also suggest that multilinear regression model M-3 gives a better representation of the climate system and using three parameters reduces the uncertainties in the developed model.

Energy pay-back time analysis of solar energy systems; photovoltaics and solar collectors

<p>Las tecnologías de energía solar se están considerando cada vez más en el suministro de soluciones energéticas eficientes para una amplia variedad de aplicaciones para generar electricidad y calor. Se registraron altas tasas de recompensa en diferentes niveles para ambos sistemas de energía solar; Sistemas solares térmicos (ST) y fotovoltaicos (FV). La explotación de la energía solar depende de la disponibilidad de recursos y las condiciones locales en cada región. Por lo tanto, este documento presenta un estudio realizado en la ciudad de Guimaráes, en el norte de Portugal. Su objetivo es evaluar la eficiencia energética de varios tipos de ambos sistemas FV y ST existentes en el mercado. El estudio realiza un análisis comparativo tanto de los módulos fotovoltaicos como de los colectores solares térmicos, como sistemas que normalmente se implementan para generar energía eléctrica y agua caliente sanitaria, respectivamente, a una escala doméstica. La energía incorporada en ambos sistemas y sus componentes se estimará basándose a la revisión literaria y siguiendo el modelo "de la cuna a la puerta" que considera las fases del ciclo de vida durante el proceso de fabricación. La energía producida por cada uno de los sistemas se estimará en este estudio utilizando el software de simulación portugués SCE.ER. Los resultados muestran los valores estimados del tiempo de recuperación de energía de cada uno de los sistemas examinados de los colectores solares y fotovoltaicos .<br /><br /><br /></p>

Evaluation of Thermodynamic Analysis of Solar Energy Systems Integrated into Sustainable Buildings with Artificial Neural Network: A Case Study

With the increasing concern on the environment and climate change, scientists focused on the way in which new structures, especially in the field of energy. In this sense, the concept of sustainable buildings is developing day by day in terms of energy efficiency. The sustainable building concept identifies five objectives which are resource efficiency, energy efficiency, prevention of pollution, harmonization with the environment; and also using integrated and systemic approaches. To increase energy efficiency in buildings, the integration of Solar Energy Systems into buildings attaches importance in terms of sustainable engineering designs. Evacuated Tube Heat Pipe (ETHP) solar energy systems are also noteworthy in this regard. This paper presents the results of an experimental study that is an ETHP solar collector system. ETHP systems are an alternative solar energy system to low-efficiency planary collectors. Only water was used to avoid losses in the heat transfer from the fluid to the fluid. Water is inserted in the vacuum tube in order to improve the rate of heat transfer, such that the mode of heat transfer from the inner surface of the vacuum tube to the heat pipe becomes convection via the water, as well as conduction through the installed. The exergy efficiency of the ETHP system was calculated as 32.94%. For a long time, artificial neural networks (ANN) have been widely applied in energy efficiency for modeling and optimization of various processes. In the field of processing, recent studies confirm the validity and effectiveness of using ANNs as promising and most powerful computer modeling techniques. Within the scope of this study, exergy efficiency was evaluated on the developed Artificial Neural Network algorithm. The effect rates of parameters such as pressure, temperature, and ambient temperature affecting exergy efficiency were calculated. Finally, significant findings obtained were evaluated in terms of thermodynamics rules.

Production of solar radiation bankable datasets from high-resolution solar irradiance derived with dynamical downscaling Numerical Weather prediction model

Abstract A bankable solar radiation database is required for the financial viability of solar energy project. Accurate estimation of solar energy resources in a country is very important for proper siting, sizing and life cycle cost analysis of solar energy systems. During the last decade an important progress has been made to develop multiple solar irradiance database (Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI)), using satellite of different resolution and sophisticated models. This paper assesses the performance of High-resolution solar irradiance derived with dynamical downscaling Numerical Weather Prediction model with, GIS topographical solar radiation model, satellite data and ground measurements, for the production of bankable solar radiation datasets. For this investigation, NWP model namely Consortium for Small-scale Modeling (COSMO) is used for the dynamical downscaling of solar radiation. The obtained results increase confidence in solar radiation data base obtained from dynamical downscaled NWP model. The mean bias of dynamical downscaled NWP model is small, on the order of a few percents for GHI, and it could be ranked as a bankable datasets. Fortunately, these data are usually archived in the meteorological department and gives a good idea of the hourly, monthly, and annual incident energy. Such short time-interval data are valuable in designing and operating the solar energy facility. The advantage of the NWP model is that it can be used for solar radiation forecast since it can estimate the weather condition within the next 72–120 hours. This gives a reasonable estimation of the solar radiation that in turns can be used to forecast the electric power generation by the solar power plant.

Exergy Analysis of Solar Energy Systems for Sustainable Buildings

Exergy analysis has been widely applied in parallel with energy analysis in order to find the most rational use of energy. Low exergy systems are defined as heating or cooling systems that allow the use of low valued energy, which is mostly delivered by solar energy (i.e., solar collectors, hybrid PV/T panel) as the energy source. Low exergy building systems create more flexibility and generate new possibilities for the design of sustainable buildings. Usage of solar energy in different kinds of systems provides scope for several studies on exergy analysis. The present study comprehensively reviews the studies conducted on the exergy analysis of various solar energy systems for establishing the sustainable buildings. Conclusions regarding the usability of the exergy method as a tool to promote a more efficient use of solar energy sources are derived, with the aim to highlight future research issues and promote further developments of this method.

Estimation of monthly solar radiation distribution for solar energy system analysis

Abstract The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors.

Framework for analysis of solar energy systems in the built environment from an exergy perspective

Exergy analysis is a more powerful tool than mere energy analysis for showing the improvement potential of energy systems. Direct use of solar radiation instead of degrading other high quality energy resources found in nature is advantageous. Yet, due to physical inconsistencies present in the exergy analysis framework for assessing direct-solar systems commonly found in literature, high exergy losses arise in the conversion process of solar radiation in direct-solar systems. However, these losses are disregarded in indirect-solar systems. In this paper, contradictions and physical inconsistencies which result from including the conversion of solar radiation only for direct-solar systems are shown. An evaluation framework physically coherent for systems making direct and indirect use of solar radiation is derived and its physical correctness is thoroughly discussed. Results from case studies using the proposed framework are presented and compared with the conventional approach, enabling their direct comparison and better understanding of the benefits and correctness of the proposed method. The new method allows recognizing clearly the suitability of direct-solar systems, being appropriate for highlighting more sustainable energy supply systems. Although this paper focuses on building systems, the framework might be used for exergy analysis of direct-solar systems in the context of other energy uses.

04/02426 Multi-criteria evaluation of cooking energy alternatives for promoting parabolic solar cooker in India: Pohekar, S. D. and Ramachandran, M. Renewable Energy, 2004, 29,(9), 1449–1460

This study performs a regional economic analysis of solar energy systems in Eskisehir, Turkey that focuses on production and utilization of FPSCs. The data is obtained from a locally conducted survey and used for practical estimations. Both, the survey findings and the theoretical predictions give close results and they sustain each other. Under the condition of free market considering profit maximization, to produce 30 FPSCs per day in optimum conditions, 30 workers would be employed per shift. If a company can meet the market demand, 450,000,000 Turkish Liras (TL) (1$=2.85TL with current prices) of revenue will be earned from the production of 300,000 FPSCs in 30 years are displayed. On the other hand, this renewable energy system has some costs. However, once it has been set up, the system will produce many ecological advantages that more than offset its costs. These effects benefit both the local region in which the system is established and the environment on a global scale. In addition, the process of collecting and utilizing solar energy can be used together with recycling systems to generate advantages for a local economy and can also benefit the global economy by solving unemployment problems by creating employment opportunities.

Economic analysis of solar energy systems using spreadsheets

In this paper the method employed for a detailed economic analysis of a solar energy system is presented. A spreadsheet computer program is used as a tool for the economic analysis because the general format of such a program is a table with cells which can contain values or formulae and the fact that they incorporate many build-in functions. System optimisation is also presented through an example for a hot water system. Both of them show that the method presented here is both accurate and fast. Although the method presented here deals with solar systems, it is applicable to all energy producing systems and consequently to all renewable energy systems.

A method for technical-economic analysis of solar heating systems

The necessity for technical-economic analysis of solar energy systems is obvious when assessing their feasibility vis-á-vis conventional alternative systems. Optimum magnitudes of the installation parameters should be defined under the required economic conditions. In this study, the optimization procedure was chosen so as to maximize the total accumulated saving throughout the economic lifetime of the system. The annual solar heating fraction of the system is assessed using the f-chart method which can be used for both domestic hot water and space heating. The saving produced by investing in a solar installation is obtained by taking the difference between the total discounted expenditures of the conventional and the solar systems, accumulated during their foreseen lifetimes. To this end, the present value method is applied, taking into account the initial investment costs, fuel costs, operation costs and the maintenance costs for both the solar system and its conventional alternative. Based on this technical-economic analysis, a computer program is developed. This accepts three types of input data: technical design, economic parameters and meteorological conditions, and calculates the optimum magnitudes of the design parameters. It is concluded that economic parameters are much more influential on the system economics than the technical parameters. The most significant are the payback period and the internal rate of return.

Preliminary design and economic analysis of solar-energy systems for heating and cooling of buildings

This article presents an overview of the current state of solar system design and optimization analysis for low temperature applications. It emphasizes the design of collector systems for heating and cooling of buildings and presents a simple economic analysis to determine the actual cost of thermal energy delivered by a solar collector system under given environmental conditions.