Solar Radiation Year Research Articles

Thermo-economic optimization of solar organic Rankine cycle based on typical solar radiation year

The thermo-economic optimization of a solar organic Rankine cycle (SORC) should consider the features of fluctuations in solar radiation based on local historical solar radiation. However, the use of historical solar radiation is inconvenient for thermo-economic optimization because it involves considerable computational effort for simulation. To overcome this inconvenience, we propose the thermo-economic optimization of SORC by using typical solar radiation year (TSRY). TSRY is a synthesis of typical solar radiation on the basis of historical solar radiation, indicating that TSRY can reflect the typical features of fluctuations in solar radiation in a specific area. Afterward, the multi-objective genetic algorithm (GA) is selected to optimize the dynamic performance of a small-scale SORC by using the TSRY. In GA, the evaporation temperature and capacity of thermal energy storage are taken as optimization parameters, and the power output and fluctuation in power output are optimization goals. Accordingly, Pareto frontiers that optimize the SORC performance can be obtained. The effect of different parameter combinations in the Pareto frontiers and the scale of the SORC on thermo-economic are further analyzed using annual net profit as an indicator. Our analysis shows that a minimum SORC scale for profitability is set for a given location, and the profit growth rate increases as the system scale increases.

Typical solar radiation year construction using k-means clustering and discrete-time Markov chain

Daily solar radiation (DSR) fluctuation and transition rules affect the design of the energy storage system and online control strategy of solar energy utilisation systems. However, the current synthesis methods for the typical meteorological year do not emphasise such features of DSR. To overcome this shortcoming, this study presents an innovative synthesis method for a Typical Solar Radiation Year (TSRY) based on k-means clustering and discrete-time Markov chain (DTMC). The historical distributions of clear-sky ratio (CSR) in four representative regions were analysed, and a six-dimensional feature vector that represents the DSR fluctuations based on CSR was defined. Then, based on the feature vector, k-means clustering was used to cluster the historical DSR into four types. Subsequently, a DTMC-based model was built for transition rule estimation among the four types of solar radiation. Finally, the TSRY was established based on the clustering categories and transition rules among them. The innovative synthesis method was also verified in this study. Results for the four regions showed that the average error of the synthesised TSRY has maximum and minimum values of 10% and 6% in all seasons, respectively, compared with historical data. The proposed method could represent DSR fluctuation and transition characteristics of certain regions and could also be extended to other regions.

Optimistic / Normal / Pessimistic Limits of Global Solar Radiation in Urban Armidale NSW, Australia

The most common data for describing the local solar climate is through what is called Typical Meteorological Year data (TMY). Typical solar radiation data is very important for the calculations of many solar applications. In this study, typical solar radiation years for Armidale town in New South Wales in Australia are generated from the daily global solar radiation data measured for 23 years, utilising the Finkelstein-Schafer statistical method. The study outcome provides optimistic, normal and pessimistic expected global solar radiation in Armidale all over the year based on previous studies conducted based on meteorological historical measured data in Armidale's Airport Weather Automatic Weather Station. Such outcome presents a handy database of global solar radiation to be utilised by solar energy's specialists for detailed calculations and/or ordinary persons for initial assessment of solar energy in Armidale.

TAKAGI-SUGENO ALGORITHM FOR GLOBAL SOLAR IRRADIATION USING AIR TEMPERATURE DATA

Air temperature is certainly the most measured surface meteorological parameter and accurate forecasting of air temperature is usually performed worldwide. This fact inspired the idea that a predicted value of air temperature may be used as input in solar radiation air temperature-based models, aiming to generate the reference solar radiation year or to forecast solar irradiation. Following this, a Takagi-Sugeno fuzzy model for estimating global solar irradiation via air temperature data is reported here. This is intended to be a simple and accurate tool for solar engineering use. Since air temperature-based models are sensitive to the origin locations, an approach for enlarging the area of application is presented. A critical assessment of the model performance against measured data is conducted, with overall results demonstrating a level of accuracy suitable for most practical applications.

Distribution of Solar Diffuse Fraction in Taiwan

A simple polynomial model of the sky clearness index as predictor was proposed in this paper, for estimating the hourly solar diffuse fractions in Taiwan. The error analysis was performed through two statistical indicators, the mean bias error and the root-mean-square error. The out of database validation was also made to confirm the model generality. Next, regressions between monthly averaged conditions and geographical parameters of places (latitude, longitude, and elevation above sea level) were discussed, using the model's estimates and the updated data sets of typical solar radiation year. Based on the results, diffuse fraction maps for two observation periods were presented in 1-km resolution via an aid of linear interpolation.

Using Modified Sandia Method in Developing Typical Solar Radiation Year for Photovoltaic Electricity Generation Projection

The energy generation efficiency of Building Intergraded Photovoltaic Systems (BIPV) system relies much on the panel’s surface solar radiation received. In the projection of annual power generation of photovoltaic panels, local global solar radiation plays a pivotal role for reliable estimation process. The purpose of this paper is to develop an hourly typical solar radiation year (TSRY) as fundamental meteorological database for utilizing the estimation process. The TSRY should be interpretable to local long-term climate variations, thus, ten years' hourly meteorological data were gathered to formulate a typical year by means of modified Sandia method herein. A total of four cities' hourly typical years from northern to southern Taiwan were established in this paper. Orientation and inclination effect of the PV panel were also discussed in terms of daily averaged global solar radiation that cumulate from TSRY.

Generation of representative solar radiation data for Aegean Region of Turkey

Typical solar radiation data is needed in calculation and assessment of many solar energy applications. In this study, typical solar radiation years for seven provinces located in Aegean Region of Turkey were generated from the daily global solar radiation data measured during at least for 15 years, using the Finkelstein-Schafer statistical method. The typical daily global solar radiation data for the locations considered were presented throughout a year in a tabular form. The data obtained were also analyzed. It is expected that the typical data presented for Aegean Region will be useful to the designers of solar energy systems. Key words: Finkelstein-Schafer method, solar radiation, test reference year, Aegean region, Turkey.

Reference Solar Radiation Year and Some Climatology Aspects of East Coast of West Malaysia

Problem statement: This study examined in detail some aspects of radia tion climatology for Terengganu state in Malaysia. The geographical co-ordinates of the site are 5°10'N latitude 103°06'E longitude and 5.2 m altitude. Approach: The data used in the present study were taken from a recording data station installed at site by the M alaysian Meteorology Department (2004). In addition to this, wind speed, solar radiation and air temper ature data taken from University Malaysia Terengganu Renewable Energy Station were also analyzed. The averaged solar radiation year for Terengganu is generated from mid-term daily global solar radiation data. The averaged data of the daily global solar radiation for the locations cons idered are presented in a tabular form for a comple te year. Results: The highest daily and monthly mean global solar irr adiation values were 7560 and 6566 Wh m -2 day -1 , respectively. The highest hourly average solar ir radiance intensity was 1139 W m -2 during this study period. Yearly average daily sol ar energy was 18.92 MJ m -2 day -1 . Besides the global solar radiation, the clearness indexes, wind speed and air temperature variation are discussed. Conclusion/Recommendations: The results in this study will fill the gap that c omplete and detailed reference solar radiation and climatologically data , which are not available for Terengganu state of Malaysia and will be useful to the designers of sol ar energy conversion and utilization devices.

Generation of Typical Solar Radiation Year for Mediterranean Region of Turkey

Typical solar radiation data is very important for the calculations concerning many solar applications. In this study, typical solar radiation years for six provinces located in the Mediterranean region of Turkey are generated from the daily global solar radiation data measured at least for 14 years, using the Finkelstein-Schafer statistical method. The typical daily global solar radiation data for the locations considered is presented throughout a year in a tabular form. The data obtained is also analyzed. It is expected that the typical data presented for the Mediterranean region, which is rich for solar energy potential in Turkey, will be useful to the designers of solar energy systems.

Generation of typical solar radiation year for China

Applying the daily global solar radiation data measured at least 10 years, the typical solar radiation year for 30 meteorological stations in China is generated using the Finkelstein–Schafer statistical method. Based on the typical solar radiation data obtained, the geographical difference of solar energy resource of these 30 stations was also analyzed. The results in this paper will fill this gap that complete and detailed typical solar radiation data are not available for China, and will be useful to the designers of solar energy conversion and utilization devices.

04/02442 Typical solar radiation year for southeastern Anatolia: Bulut, H. Renewable Energy, 2004, 29, (9), 1477–1488

04/02442 Typical solar radiation year for southeastern Anatolia: Bulut, H. Renewable Energy, 2004, 29, (9), 1477–1488

Typical solar radiation year for southeastern Anatolia

The typical solar radiation year for seven provinces located in the southeastern Anatolia region of Turkey is generated from daily global solar radiation measured at least for 14 years, using the Finkelstein–Schafer statistical method. The typical data of the daily global solar radiation for the locations considered are presented throughout a year in a tabular form. The data obtained are also analyzed. It is expected that the presented typical data for southeastern Anatolia region, which has the highest solar energy potential in Turkey, will be useful to the designers of solar energy systems.

Economic analysis of small photovoltaic facilities and their regional differences

Small grid-connected photovoltaic (PV) facilities in Spain receive either a premium of 0.36€ kWh−1 over the average price on the power market or a fixed price of 0.40€ kWh−1. However, legislation on this matter (Royal Decree 2818/98) requires a periodic review of these figures. The basis of on-going revision of these prices has been their profitability. However, the economic success of such PV facilities is clearly affected by the amount of solar radiation at the site where they are located. Since Spain is between latitudes 44 and 36° in the northern hemisphere, the feasibility of these systems must be analysed for different regions. Two different models have been used to produce the required input data for such an analysis: a model that generates typical solar radiation years and temperatures taken from satellite images and an empirical model for the prediction of daily power produced by a grid-connected photovoltaic system. From the results of this regional economic analysis, it may be concluded that the existing prices are insufficient in and of themselves to make these small grid-connected systems profitable anywhere in Spain. To guarantee the economic feasibility of these PV installations in any given location, the fixed price paid for the electricity should be around 0.93€ kWh−1. Nevertheless, if the Government were to double the current fixed price, in consideration of the slow increase in the PV market in recent years, this would mean that small grid-connected installations would become profitable in at least 77% of the Spanish territory. Copyright © 2004 John Wiley & Sons, Ltd.

Analysis of the Dry Matter Production Process Related to Yield and Yield Components of Rice Plants Grown under the Practice of Nitrogen-Free Basal Dressing Accompanied with Sparse Planting Density

ReferencesExperiments were carried out in 1999, 2000 and 2001 on the field of Iwate University, Japan to examine the effect of nitrogen-free basal dressing accompanied with sparse planting density (BNo) on the dry matter production (DMP) of 12 rice cultivars or lines belonging to the early, medium and late-maturing genotypes. During the period from transplanting to panicle initiation (PI), DMP was lower in BNo than in the conventional cultivation (CONT) in all 3 years. The DMP during the period from PI to full heading (FH) was also lower in BNo than in CONT, particularly in the high solar radiation year of 1999, because of the small leaf area index. During the ripening stage, leaf area index in BNo was smaller, but crop growth rate in BNo was similar to or higher than that in CONT due to the large net assimilation rate, which resulted from the largeflag leaf and 2nd leaf, and the heavy specific leaf weight in BNo. The DMP per panicle during the period from PI to FH positively and significantly correlated with the number of spikelets panicle-1. The percentage of ripened grains (PRG) was also closely related with the amount of carbohydrates from stems (ᴪჭS) and photosynthesis after FH (ǭW) contributed to a spikelet during the early ripening period (during 20 days after FH). The higher DMP per panicle in BNo compared with CONT during the period from PI to FH, therefore, resulted in a larger number of spikelets panicle-1 in the former. On the other hand, the large amount of carbohydrate supply per spikelet during the early ripening period could also secure a high and stable PRG in BNo, especially under unfavorable weather conditions.

Typical solar radiation year for Egypt

The Typical Solar Radiation Year (TSRY) for Egypt is generated by using daily data of global solar radiation obtained by measurements at 10 stations for long periods. Also, the hourly values of different components of solar radiation (direct, diffuse and global) over these 10 stations are estimated for the typical day (midday) of each month by applying empirical models and using the standard meteorological data for each station.