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.     

Estimation of daily diffuse solar radiation in China

Applying the measured global and diffuse solar radiation data from 78 meteorological stations in China, a countrywide general correlation model for calculating the daily diffuse radiation was derived on the basis of Liu and Jordan method. Two widely used statistics: root mean square error and mean bias error were used to assess the performance of the correlation. And the correlation shows good behavior when applied to most of the stations. Subsequently, with the measured data from the 78 stations, an analysis of geographical distribution of solar energy resource in China was also presented in the form of clearness index (the ratio of global solar radiation to extraterrestrial radiation) percentage frequency, and results show that the solar energy resource in western and northern China is relatively abundant.     

Modeling of the radiation field in a parabolic trough solar photocatalytic reactor

We calculate the distribution of absorbed radiation inside a solar photocatalytic reactor, by means of radiative transfer theory. The reactor configuration is that of a glass tube illuminated by a parabolic trough collector, where the catalyst consists of titanium dioxide micro-particles suspended in water. The calculations are made within the framework of the P1 approximation, which allows to solve analytically the radiative transfer equations. The obtained solution is used to study the effect of catalyst concentration on the degradation of pollutants, by means of a general kinetic model. The results obtained display the main features which are observed in experiments reported in the literature.     

Some recommendations for inclinations and orientations of building elements under solar radiation in Polish conditions

The paper considers solar energy availability on the different surfaces that constitute the building envelope. The main aim of the presented analysis is to give recommendations for architects to help them design standard and low energy buildings in a proper way, including integration of solar active and passive systems into building structure. This requires maximisation of solar energy gains during certain periods of time, and at other times shading.     

Application of real-time spectroscopic ellipsometry for characterizing the structure and optical properties of microcrystalline component layers of amorphous semiconductor solar cells

Over the past few years, we have applied real-time spectroscopic ellipsometry (RTSE) to probe hydrogenated amorphous silicon (a-Si:H)-based solar cell fabrication on the research scale. From RTSE measurements, the microstructural development of the component layers of the cell can be characterized with sub-monolayer sensitivity, including the time evolution of (i) the bulk layer thickness which provide the deposition rates, and (ii) the surface roughness layer thickness which provide insights into precursor surface diffusion. In the same analysis, RTSE also yields the optical properties of the growing films, including the dielectric functions and optical gaps. Results reported earlier have been confined to p-i-n and n-i-p cells consisting solely of amorphous layers, because such layers are found to grow homogeneously, making data analysis relatively straightforward. In this study, we report the first results of an analysis of RTSE data collected during the deposition of an n-type microcrystalline silicon (μc-Si:H) component layer in an a-Si:H p-i-n solar cell. Such an analysis is more difficult owing to (i) the modification of the underlying i-layer by the H₂-rich plasma used in doped μc-Si:H growth and (ii) the more complex morphological development of μc-Si:H, including surface roughening during growth.     

Fabrication of n–p junction electrodes made of n-type SnO2 and p-type NiO for control of charge recombination in dye sensitized solar cells

The n–p junction electrode fabricated coating nanocrystalline SnO₂ thin film with a thin layer of p-type NiO was found to increase the sensitized photocurrent and photovoltage. In addition, increase in the fill factor was noticed due to inhibition of electron back transfer from SnO₂ to the redox electrolyte (I₃⁻) by both junction effect and presence of NiO barrier, resulting in much better energy conversion efficiencies. The highest cell efficiency was obtained for the cell fabricated by immersing SnO₂ thin films in soluble Ni salts, and converting them to NiO by firing. The optimum NiO coating thickness was found to be only a few angstroms and the energy levels of the excited dye and the conduction band position of NiO suggest that the electron transfer from the excited dye to the underlying SnO₂ layer occurs by tunneling through the p-type NiO layer.     

Reliability analysis of solar photovoltaic system using hourly mean solar radiation data

This paper presents the hourly mean solar radiation and standard deviation as inputs to simulate the solar radiation over a year. Monte Carlo simulation (MCS) technique is applied and MATLAB program is developed for reliability analysis of small isolated power system using solar photovoltaic (SPV). This paper is distributed in two parts. Firstly various solar radiation prediction methods along with hourly mean solar radiation (HMSR) method are compared. The comparison is carried on the basis of predicted electrical power generation with actual power generated by SPV system. Estimation of solar photovoltaic power using HMSR method is close to the actual power generated by SPV system. The deviation in monsoon months is due to the cloud cover. In later part of the paper various reliability indices are obtained by HMSR method using MCS technique. Load model used is IEEE-RTS. Reliability indices, additional load hours (ALH) and additional power (AP) reduces exponentially with increase in load indicates that a SPV source will offset maximum fuel when all of its generated energy is utilized. Fuel saving calculation is also investigated. Case studies are presented for Sagardeep Island in West Bengal state of India.     

Synthesis and characterization of β-FeSi2 grown by thermal annealing of Fe/Si bilayers for photovoltaic applications

In this article we have reported the synthesis and characterization of FeSi₂ thin films. The Fe/Si thin films were obtained by electron beam evaporation. Thermal annealing was carried out at 650°C for 1 h. The formation of the β-FeSi₂ layers were characterized by the X-ray diffraction method and found to be polycrystalline in nature. The structural parameters were evaluated from the XRD pattern. The possible optical transition in these films is found to be direct and allowed.