Performance Of Solar Energy Systems Research Articles

Techno-economic and environmental analysis of an integrated standalone hybrid solar hydrogen system to supply CCHP loads of a greenhouse in Iran

ABSTRACTThe techno-economic and environmental performance of hybrid solar hydrogen energy systems was investigated to provide combined cooling, heating and power (CCHP) demands of a standalone greenhouse in Iran to achieve sustainable agriculture based on an optimization procedure. From the environmental point of view, by deploying hybrid energy systems, 83%, to 100% of emissions can be avoided. Also a sensitivity analysis was performed on the hybrid energy systems in order to study the effect of major parameter variation on the systems justification. It was concluded that hybrid solar systems are economically competitive with conventional systems, for high solar intensity locations with high diesel fuel prices and decreased prices for PV and hydrogen storage technology.

Life-cycle Assessment Applied to Photovoltaic Energy: A Review

The aim of this study is to evaluate the environmental performance of different photovoltaic solar energy systems through a review of the scientific literature concerning the life-cycle assessment applied to different photovoltaic systems and using the ISO 14040 and ISO 14044 standards. A comparison between solar photovoltaic systems and conventional systems, power generation is performed. Through the LCA the environmental impacts associated with the analyzed throughout their life cycle systems were tested. These results show, in terms of cumulative energy demand (CED), that for the case of monocrystalline silicon (mc-Si) as one of the most used raw materials, 75.8% of 5150 MJ corresponding to the manufacture of 1m2 of photovoltaic module is required. As for the environmental performance, this technology produces only 0.7 g/GWh of greenhouse gas emissions, compared to 3.7 g/GWh and 44.3 g/GWh produced from sources such as oil and coal, respectively. Photovoltaic technology generates lower emissions corresponds to Cadmium - Tellurium (CdTe) solar cells with 0.3 g / KWh of greenhouse gas emissions. First, it was found that, during manufacture of photovoltaic panels, a contribution of CO2equ emissions is mainly related to the transformation of silicon micro granular and it corresponds to 47.61% of emissions per GWP. Second, emissions are related to the assembly of the panels (18.39%) and, thirdly, casting and production of wafers (16.54% of GWP emissions).

Determining the best model for estimation the monthly mean daily global solar radiation on a horizontal surface – A case study in Nigde, Turkey

Knowledge of the local solar radiation is important for many applications of solar energy systems. The global solar radiation on horizontal surface at the location of interest is the most critical input parameter employed in the design and prediction of the performance of solar energy systems. In this study, 3 empirical sunshine based models are compared correlating the monthly mean daily global solar radiation on a horizontal surface with monthly mean sunshine records for Nigde, Turkey. Models are compared using coefficient of determination (R2), the root mean square error (RMSE), the mean bias error (MBE) and the t-statistic. According to our results, all the models fitted the data adequately and can be used to estimate the specific monthly global solar radiation. The t-statistic was used as the best indicator; this indicator depends on both, and is more effective for determining the model performance. The agreement between the estimated and the measured data were remarkable and the method was recommended for use in Nigde, Turkey.

English

This paper presents themodelling and design of the photovoltaic generator using Simscape MATLAB/Simulink and also design the performance of present stand-alone solar photovoltaic energy system with perturbation and observation (P and O) and artificial intelligence like fuzzy logic based maximum power point tracking (MPPT) algorithm. The system is intended for solar PV panels of 400 cells. Perturb and Observe and fuzzy logic method is used for tracking of Maximum power point (MPPT) which increases efficiency of the PV generator. In this paper the I-V and P-V characteristics of the PV generator are show and also show the scope result with respect to time. According to the P and O method or the fuzzy logic method, the array terminal voltage is always adjusted according to the MPP voltage and the duty cycle is adjusted directly in the algorithm. The system as good dynamic response and good tracking accuracy and increases the efficiency of the PV generator. The different results are presented in the form of the characteristic of the PV generator.

Comparison of Empirical Models for the Estimation of Monthly Global Solar Radiation at Nigde in Turkey

Aims: Comprehension of the local solar radiation is important for many applications of solar energy systems. The global solar radiation on horizontal surface at the location of interest is the most critical input parameter employed in the design and prediction of the performance of solar energy systems.

Optimal Choosing of Hybrid Renewable Source for Varying Condition for Effective Load Managemet

The goal of this thesis is to evaluate the performance of a hybrid solar wind, fuel cell and battery energy system through Mat lab simulation studies. The main objective of this study is the development of dynamic models of an off grid (standalone) solar wind turbine, fuel cell and battery system which is used for charging and discharging. Maximum power can be extracted from PV module by using Maximum Power Point Tracking (MPPT) by controlling the duty cycle of a switch. The developed model of the wind energy conversion system consists of dynamic models for a wind turbine as well as induction motor or Permanent Magnet Synchronous Machine. In this thesis we have to control the sources depending upon the load condition. The solar installation cost is less than the remaining sources. So solar supplies the load continuously. If solar cell generated power is not sufficient, then the wind supplies. And if solar and wind generated power are not sufficient, then fuel cell will be operated along with solar and wind. A battery which is used for backup purpose will supply if solar, wind, fuel cell generated power is not sufficient.

Annual measured performance of building-integrated solar energy systems in demonstration low-energy solar house

This paper presents the details of the output and efficiency of the annual performance of building-integrated solar energy systems for a solar water heating system and solar photovoltaic (PV) modules of a demonstration near-zero-energy solar house that was constructed on the campus of the Korea Institute of Energy Research. The thermal systems installed in the house were a solar water heating system with building-integrated solar collectors for water heating and for part of the space heating, and a ground-coupled heat pump for space cooling and part of the space heating. Solar PV modules were installed on the roof of the house. The performance of these systems was monitored for more than 1 yr. The annual efficiencies of the building's integrated solar collectors and solar PV were 22.8% and 10.9%, respectively. The total annual solar fraction of the solar heating system was 69.7%, with an annual solar heat production of 248 kW h/m2. This paper also focuses on the efficiency of the house's solar storage, based upon intentionally varied drainage of hot water from the storage tank. It was found that the thermal loss from the solar storage tank has a strong functional relationship with the thermal demand of the solar storage tank per unit volume. For example, when the hot water consumption was reduced by half during September, the thermal loss increased to more than 70%, which would otherwise have been around 30%.

Parameter identification of solar cells using artificial bee colony optimization

In order to improve the performance of solar energy systems, accurate modeling of current vs. voltage (I–V) characteristics of solar cells has attracted the attention of various researches. The main drawback in accurate modeling is the lack of information about the precise parameter values which indeed characterize the solar cell. Since such parameters cannot be extracted from the datasheet specifications, an optimization technique is necessary to adjust experimental data to the solar cell model. Considering the I–V characteristics of solar cells, the optimization task involves the solution of complex non-linear and multi-modal objective functions. Several optimization approaches have been proposed to identify the parameters of solar cells. However, most of them obtain sub-optimal solutions due to their premature convergence and their difficulty to overcome local minima in multi-modal problems. This paper proposes the use of the ABC (artificial bee colony) algorithm to accurately identify the solar cells' parameters. The ABC algorithm is an evolutionary method inspired by the intelligent foraging behavior of honey bees. In comparison with other evolutionary algorithms, ABC exhibits a better search capacity to face multi-modal objective functions. In order to illustrate the proficiency of the proposed approach, it is compared to other well-known optimization methods. Experimental results demonstrate the high performance of the proposed method in terms of robustness and accuracy.

A Software Optimization of the Solar Energy System Performance

The energy demand of buildings represents in the balance of heat use and heat consumption of energy complex in the Slovak national economy second largest savings potential. Their complex energy demands is the sum of total investment input to ensure thermal protection and annual operational demands of particular energy systems during their lifetime in building. The application of energy systems based on thermal solar systems reduces energy consumption and operating costs of building for support heating and domestic hot water as well as savings of non-renewable fossil fuels. Correctly designed solar energy system depends on many characteristics, i. e. appropriate solar collector area and tank volume, collector tilt and orientation as well as quality of used components. The evaluation of thermal solar system components by calculation software shows how can be the original thermal solar system improved by means of performance. The system performance can be improved of more than 31 % than in given system by changing four thermal solar system parameters such as heat loss coefficient and aperture area of used solar collector, storage tank volume and its height and diameter ratio.

An Automatic High Efficient Method for Dish Concentrator Alignment

Alignment of dish concentrator is a key factor to the performance of solar energy system. We propose a new method for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our method.

Estimation of Hourly Solar Radiation on Horizontal and Inclined Surfaces in Western Himalayas

The hourly solar radiation data required for solar energy system design evaluation and performance studies is gener-ally not available for a number of sites especially in remote locations. As such accurate determination of hourly solar radiation data, is important both at horizontal; surfaces and inclined surfaces. A model to estimate global solar radiation using temperature and sunshine hour data has been developed (Chandel et al. [1]) which is used to calculate the hourly solar radiation Data. The hourly solar radiation has also been calculated using Gueymard [2] daily integration approach from the measured daily solar radiation data. These two predicted hourly solar radiation data values are compared with measured hourly values to test the accuracy of the models. The total solar radiation on the inclined surfaces and vertical surfaces for different orientations, have also been estimated. The estimated values are found to be in close agreement with measured values. The method presented can be used to estimate hourly, global, diffuse solar radiation for horizontal surfaces and total solar radiation on inclined and vertical surfaces at different orientations with greater accuracy for any location.

The impact of geometrical parameters on the thermal performance of a solar receiver of dish-type concentrated solar energy system

A three-dimensional model of parabolic dish-receiver system with argon gas as the working fluid is designed to simulate the thermal performance of a dish-type concentrated solar energy system. The temperature distributions of the receiver wall and the working gas are presented. The impact of the aperture size, inlet/outlet configuration of the solar receiver and the rim angle of the parabolic dish are investigated. The results show that the aperture size and different inlet/outlet configuration have a considerable impact on the receiver wall and gas temperatures, but the rim angle of the parabolic dish has negligible influence.

Energy simulation of solar assisted absorption system and examination of clearness index effects on auxiliary heating

Abstract The smog and pollutants in the atmospheric air of heavily populated urban areas are anticipated to have substantial adverse effects on the collection of solar energy and the performance of solar energy systems. The objectives of this study are (a) to develop a simulation model for analyzing the performance of a water–LiBr solar assisted absorption system with an auxiliary heating source and (b) to examine the effects of clearness index on the auxiliary heating requirements. To achieve the objectives, a numerical model for a water–LiBr solar assisted absorption system is developed, and the influence of a reduction in the clearness index, based on actual recorded data, is investigated for constant and time varying cooling loads. Under the condition of peak solar gain on July 21, when a 1000 m 2 solar collector is designed to provide 70% of the heating energy required for a constant cooling load of 1265 MJ/h (=100 refrigeration tons), as the system coefficient of performance decreases due to higher ambient temperatures, it is found that a reduction in the clearness index from 0.63 to 0.52 results in a 67% increase in auxiliary heating required of the boiler. It is concluded that accounting for clearness index data is necessary for accurate prediction of solar energy collection.

Analysis of short-term solar radiation data

Solar radiation data are available for many locations on an hourly basis. Simulation studies of solar energy systems have generally used these hourly values to estimate long-term annual performance, although solar radiation can exhibit wide variations during an hour. Variations in solar radiation during an hour, such as on a minute basis, could result in inaccurate performance estimates for systems that respond quickly and non-linearly to solar radiation. In addition, diffuse fraction regressions and cumulative frequency distribution curves have been developed using hourly data and the accuracy of these regressions when applied to short-term radiation has not been established. The purpose of this research is to investigate the inaccuracies caused by using hourly rather than short-term (i.e., minute and 3 min) radiation data on the estimated performance of solar energy systems. The inaccuracies are determined by examination of the frequency distribution and diffuse fraction relationships for short-term solar radiation data as compared to existing regressions and by comparing calculated radiation on tilted surfaces and utilizability based on hourly and short-term radiation data.

New Correlation to Estimate Global Solar Radiation on Horizontal Surfaces Using Sunshine Hour and Temperature Data for Indian Sites

Solar radiation data, a prerequisite for the designing and sizing of solar energy systems, are not available in many Indian locations. However, the sunshine hour or temperature data are available for most sites from which solar radiation can be computed. New correlation models have been developed; incorporating the latitude and altitude of a site to estimate the monthly average global solar radiation on horizontal surfaces using the sunshine hour and temperature data. The models are used for computing values of six Indian stations with different geographical locations, based on 10-15years of data. The estimated values are found to be in close agreement with their measured values. The estimated data are also compared with the results using other models to test the accuracy of new models. It has been shown that the estimated values of global radiation using temperature data are also sufficiently accurate and can be utilized for sites for which even sunshine hour data are not measured. This will lead to better inputs for designing and evaluating the performance of solar energy systems including passive solar buildings.

A new method for typical weather data selection to evaluate long-term performance of solar energy systems

A new method for typical weather data selection to evaluate long-term performance of solar energy systems

A new method for typical weather data selection to evaluate long-term performance of solar energy systems

A new method is proposed for determining typical 1-year weather data from a multi-year record for evaluation of solar energy systems. The procedure is very straightforward and can be utilised with ease when determining the long-term performance of a solar hot water system (SHWS). It is made up of a concatenation of 12 months individually selected from a multi-year database. The criterion for the selection is the minimisation of error in the monthly solar gain prediction of the system. Considering this criterion, the ‘typicality’ of the weather pattern is taken into account, in addition to its influence on the behaviour of the solar system. A comparison is made between the new method and others frequently referred to in the literature. Based on simulation results for yearly, monthly and daily power delivered, six indicators have been calculated. These indicators quantify the different behaviours of the system when ‘historical’ and typical weather data are applied. The all inclusive comparison shows that the new method for deriving typical weather data leads to an accurate evaluation of the long-term performance of a SHWS.

Analysis of solar radiation measurements at Al-Arish area, North Sinai, Egypt

This paper presents basic data for a five year period from 1986 to 1990 for global and diffuse solar radiation data at Al-Arish (31°04′N, 33°49′E). These data have been processed, analysed, presented, arranged in tables and graphs and discussed. Mean annual monthly and daily total, the diurnal variation and the frequency of daily totals of global solar radiation are computed and discussed. A correlation between the hourly values of the clearness and diffuse index were obtained and the recommended correlation equations were also given. The isopleths of hourly global radiation were also designed and discussed. The frequency distribution and the frequency of extended periods of low radiation income have been studied which are of particular interest in the field performance of solar energy systems.

Modelling line-axis solar concentrators in the medium temperature range

Simple correlation based models used extensively for the prediction of the performance of solar energy systems have little spatial accuracy and do not generally allow detailed investigation into modifications in system design. The recent development of powerful low cost computers has allowed the development of tools using computational fluid dynamics for predicting the performance of solar energy systems. These models allow predictions of the spatial variation of temperature air velocity and pressure within the concentrator system to be made and realistic theoretical investigations into the effects of design modifications to be undertaken.

Stochastic design of solar energy systems

The impact of the statistical element in the behaviour of solar radiation on the performance of solar energy systems is investigated through a stochastic model constructed for diffuse radiance. A demonstration of the use of such a model in a transient simulation study of three conceptual solar thermal systems is presented. The discussion concentrates on features that would not be observed without the use of stochastic modeling. Only through stochastic simulation can certain design features be assessed quantitatively.