Typical Solar Radiation Research Articles

A Modified Method to Generate Typical Meteorological Years from the Long-Term Weather Database

A modified typical meteorological year (TMY) method is proposed for generating TMY from practical measured weather data. A total of eleven weather indices and novel assigned weighting factors are applied in the processing of forming the TMY database. TMYs of 35 cities in China are generated based on the latest and accurate measured weather data (dry bulb temperature, relative humidity, wind velocity, atmospheric pressure, and daily global solar radiation) in the period of 1994–2010. The TMY data and typical solar radiation data are also investigated and analyzed in this paper, which are important in the utilizations of solar energy systems.

Generation of typical solar radiation data for different climates of China

In this study, typical solar radiation data are generated from both measured data and synthetic generation for 35 stations in six different climatic zones of China. (1) By applying the measured weather data during at least 10 years from 1994 to 2009, typical meteorological years (TMYs) for 35 cities are generated using the Finkelstein–Schafer statistical method. The cumulative distribution function (CDF) of daily global solar radiation (DGSR) for each year is compared with the CDF of DGSR for the long-term years in six different climatic stations (Sanya, Shanghai, Zhengzhou, Harbin, Mohe and Lhasa). The daily global solar radiation as typical data obtained from the TMYs are presented in the Table. (2) Based on the recorded global radiation data from at least 10 years, a new daily global solar radiation model is developed with a sine and cosine wave (SCW) equation. The results of the proposed model and other empirical regression models are compared with measured data using different statistical indicators. It is found that solar radiation data, calculated by the new model, are superior to these from other empirical models at six typical climatic zones. In addition, the novel SCW model is tested and applied for 35 stations in China.

Efficient TMY method of practical evaluation for solar energy utilization

AbstractThe typical‐meteorological‐year (TMY) method is investigated in this letter, and TMYs of six cities in the Xinjiang Autonomous Region of China are generated based on the latest and accurate recorded weather data (air dry‐bulb temperature, relative humidity, wind velocity, and global solar radiation) in the period 1994–2009, using the Finkelstein–Schafer (FS) statistical method. Based on the actual situation in China, the letter proposes novel assigned weighting factors in the procedure of forming TMY data. The typical solar radiation data obtained from TMY data are essential for the evaluation of solar energy systems. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

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.

Photochemical reactivity of perfluorooctanoic acid (PFOA) in conditions representing surface water

Potential of perfluorooctanoic acid (PFOA) to degrade via indirect photolysis in aquatic solution under conditions representing surface water was studied. Globally distributed and bioaccumulative PFOA does not absorb solar radiation by itself, but may be potentially photochemically transformed by the natural sensitizers such as dissolved organic matter (DOM), nitrate or ferric iron. Reaction solutions containing purified water, fulvic acid (representing DOM), nitrate, ferric iron or sea water from the Baltic Sea were spiked with PFOA and irradiated with an artificial sun (290–800 nm). In comparison similar samples were also irradiated under UV radiation at 254 nm in order to study the direct photolysis. UV radiation at 254 nm decomposed PFOA to perfluoroheptanoic-, perfluorohexanoic- and perfluoropentanoic acids. The samples irradiated with an artificial sun contained no decomposition products and no decrease in PFOA concentration was observed. According to the detection limit of the products and typical solar radiation at the surface of ocean, the photochemical half-life for PFOA was estimated to be at least 256 years at the depth of 0 m, > 5000 years in the mixing layer of open ocean and > 25,000 years in coastal ocean. This is significantly more than the previously reported photochemical half-life of PFOA (> 0.96 years).

Development of a universal DC power supply using solar photovoltaic, utility and battery power sources

In this paper, a universal direct current (DC) power supply system was developed and tested in order to provide uninterrupted power for DC appliances. The system employs simple Diode OR logic for the three power sources (mains from utility power supply, the solar photovoltaic and battery). The parallel combination of the three diodes at the output functions like a comparator circuit and compares the outputs voltage of the three sources, so that the highest voltage at a particular time feeds the DC output and supplies the charging current to the battery. The universal DC power supply system was tested under various operating conditions and the results obtained showed a good performance of the system. The system outputs, when all the power sources were available, during utility power failure and when only the stored energy in the back-up battery was available were 13.8, 13.1 and 12.2V, respectively. The system guarantees an uninterrupted power supply, which can be used to power telecommunication equipment, audiovisual materials, computers, DC motor driven devices and other DC appliances. A typical day solar radiation varied from 547 W/m2 to 865 W/m2 while the generated voltage from PV varied from 11.8 V to 13.7 V. The generated voltage from solar power source increases with the increase in solar radiation.

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.

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.

Surface temperature cooling trends and negative radiative forcing due to land use change toward greenhouse farming in southeastern Spain

Greenhouse horticulture has experienced in recent decades a dramatic spatial expansion in the semiarid province of Almeria, in southeastern (SE) Spain, reaching a continuous area of 26,000 ha in 2007, the widest greenhouse area in the world. A significant surface air temperature trend of −0.3°C decade−1 in this area during the period 1983–2006 is first time reported here. This local cooling trend shows no correlation with Spanish regional and global warming trends. Radiative forcing (RF) is widely used to assess and compare the climate change mechanisms. Surface shortwave RF (SWRF) caused through clearing of pasture land for greenhouse farming development in this area is estimated here. We present the first empirical evidences to support the working hypothesis of the development of a localized forcing created by surface albedo change to explain the differences in temperature trends among stations either inside or far from this agricultural land. SWRF was estimated from satellite‐retrieved surface albedo data and calculated shortwave outgoing fluxes associated with either uses of land under typical incoming solar radiation. Outgoing fluxes were calculated from Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data. A difference in mean annual surface albedo of +0.09 was measured comparing greenhouses surface to a typical pasture land. Strong negative forcing associated with land use change was estimated all year round, ranging from −5.0 W m−2 to −34.8 W m−2, with a mean annual value of −19.8 W m−2. According to our data of SWRF and local temperatures trends, recent development of greenhouse horticulture in this area may have masked local warming signals associated to greenhouse gases increase.

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

04/01933 Generation of typical solar radiation data for Istanbul, Turkey: Bulut, H. et al. International Journal of Energy Research, 2003, 27, (9), 847–855

04/01933 Generation of typical solar radiation data for Istanbul, Turkey: Bulut, H. et al. International Journal of Energy Research, 2003, 27, (9), 847–855

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.

Generation of typical solar radiation data for ?stanbul, Turkey

Typical solar radiation data are very important as input in modelling, designing and performance evaluation of solar energy applications. In this study, typical solar radiation data were obtained for İstanbul, Turkey both from measured data and synthetic generation. Firstly, a test reference year for daily global solar radiation on a horizontal surface was generated using 19 years measured data. The daily global solar radiation as typical data for İstanbul was presented throughout a year in a tabular form. Secondly, the daily global solar radiation for İstanbul was expressed with a trigonometric equation using long-term measured data. It is expected that the typical data and the equation derived will be useful to the designers of solar energy systems as well as those who need to have fairly good estimates of daily global solar radiation for İstanbul. Copyright © 2003 John Wiley & Sons, Ltd.

Typical solar radiation data for Oman

The monthly averaged daily global solar radiation is calculated using daily data of global solar radiation obtained by measurements at six weather stations at different locations in Oman over a period of 6 years. The clearness index for a typical day (at midday) of each month is then estimated for each location. Also, the hourly values of different components of solar radiation (direct, diffuse and global) over these six stations are estimated for a typical day of each month by applying empirical models and using the standard meteorological data for each station.

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.