Advances and significance of solar reflectors in solar energy technology in Pakistan

2018 ◽  
Vol 29 (4) ◽  
pp. 435-455 ◽  
Author(s):  
Sophia Akhtar ◽  
M Khurram Hashmi ◽  
Ishaq Ahmad ◽  
Rizwan Raza

Being located in the Sun Belt, Pakistan is rich in sunlight and receives a high mean irradiation. This condition is ideal for harnessing Sun’s power for solar energy applications by using solar reflectors. In spite of possessing such a rich solar irradiation area, Pakistan is facing energy crisis because most of the energy resources are still unexploited. This paper discusses the energy crisis of Pakistan and provides the solution by putting efforts into solar energy technology, as well as devising innovative ways to incorporate solar reflectors into a solar panel and get more power generation out of it by a diminutive modification. Reflectors are used in the solar technology to concentrate the sunlight onto the solar panels. They employ glass as a base material with a silver coating and a protective layer over it. They elevate the energy input of solar panels as the whole solar spectrum is reflected on them. Materials with more reflective properties are needed to be used to increase the reflectivity and efficiency of solar reflectors. In Pakistan, no significant work is done till now towards the development of solar reflectors. If solar reflectors are used with the solar panels, then their efficiency as well as production from the solar panels will be maximized.

2021 ◽  
Vol 7 (20) ◽  
pp. 202129
Author(s):  
Vivyane Alencar Marques Araújo do Nascimento ◽  
Taynara Bastos Trindade ◽  
Clarice Maia Carvalho

ANALYSIS OF PARAMETERS FOR PHOTOVOLTAIC SOLAR ENERGY GENERATION IN ACRE, BRAZILANÁLISIS DE PARÁMETROS PARA LA GENERACIÓN DE ENERGÍA SOLAR FOTOVOLTAICA EN ACRE, BRASILRESUMOEnergia solar é obtida através de placas solares fotovoltaicas com a função de captar a energia do sol e transformar em energia elétrica, aumentando a geração de energia solar nas regiões com maior captação de energia luminosa. Assim, neste artigo analisou-se os parâmetros para geração de energia solar fotovoltaica no Acre, Brasil. Coletou-se dados referentes a insolação, temperaturas máximas e mínimas, precipitação e umidade relativa no Instituto Nacional de Meteorologia, irradiação solar, no Centro de Referências para Energias Solar e Eólica Sérgio de S. Brito, regionais do Vale do Juruá e Vale do Acre, no período de 2015-2020. As análises foram quantitativas, utilizando o cálculo da média e cálculo do plano inclinado. Na comparação das regionais, o Vale do Acre apresentou melhores resultados para geração de energia solar e com um ângulo com a maior média diária anual de irradiação solar, considerando-se projetar-se células fotovoltaicas na regional. O trabalho apresenta que o Acre possui bastante insolação e irradiação solar, indicando alto potencial de geração de energia solar para as regionais do estado.Palavras-chave: Eficiência Fotovoltaica; Radiação Solar; Temperatura da Célula Fotovoltaica; Irradiação.ABSTRACTSolar energy is obtained through photovoltaic solar panels with the function of capturing the sun's energy and transforming it into electrical energy, increasing the generation of solar energy in regions with greater capture of light energy. Thus, the parameters for the generation of photovoltaic solar energy in Acre, Brazil were analyzed. Data on insolation, maximum and minimum temperatures, precipitation and relative humidity were collected at the National Institute of Meteorology, solar irradiation, at the Reference Center for Solar and Wind Energy Sérgio de S. Brito, regions of Vale do Juruá and Vale do Acre, in the period 2015-2020. Analyzes were quantitative, using mean calculation and inclined plane calculation. When comparing the regions, Vale do Acre presented better results for solar energy generation and with an angle with the highest annual daily average of solar irradiation, considering the project of photovoltaic cells in the region. The work shows that Acre has a lot of insolation and solar irradiation, indicating a high potential for generating solar energy for the regional regions of the state.Keywords: Photovoltaic Efficiency; Solar Radiation; Photovoltaic Cell Temperature; Irradiation.RESUMENLa energía solar se obtiene a través de paneles solares fotovoltaicos con la función de captar la energía del sol y transformarla en energía eléctrica, aumentando la generación de energía solar en las regiones con mayor captación de energía luminosa. Así, se analizaron los parámetros para la generación de energía solar fotovoltaica en Acre, Brasil. Los datos sobre insolación, temperaturas máximas y mínimas, precipitación y humedad relativa fueron recolectados en el Instituto Nacional de Meteorología, irradiación solar, en el Centro de Referencia de Energía Solar y Eólica Sérgio de S. Brito, regiones de Vale do Juruá y Vale do Acre, en el período 2015-2020. Los análisis fueron cuantitativos, utilizando cálculo de medias y cálculo de plano inclinado. Al comparar las regiones, Vale do Acre presentó mejores resultados para la generación de energía solar y con un ángulo con el promedio diario anual más alto de irradiación solar, considerando el diseño de células fotovoltaicas en la región. El trabajo muestra que Acre tiene mucha insolación e irradiación solar, lo que indica un alto potencial de generación de energía solar para las regiones regionales del estado.Palabras clave: Eficiencia Fotovoltaica; Radiación Solar; Temperatura de la Celda Fotovoltaica; Irradiación.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mauro Masili ◽  
Liliane Ventura

Incident solar radiation on photovoltaic (PV) solar panels is not constant throughout the year. Besides dependence on the season, solar radiation is reliant on the location and weather conditions. For a given location on Earth, the best-fixed orientation of a PV panel can be determined by achieving the maximum incident solar irradiance throughout the year or for a predetermined period. In this paper, we use a sophisticated atmospheric radiative transfer model to calculate the direct and diffuse solar irradiation (radiant exposure) for the solar spectrum incident on PV solar panels to determine the best tilt angle of the panel in order to maximize absorption of solar radiation for selected periods. We used the Regula-Falsi numerical method to obtain the tilt angle at which the derivative of solar irradiation (concerning the tilt angle) approaches zero. Moreover, the spectral response of typical silicon cells is taken into account. These calculations were carried out in São Carlos (SP), a town in the southeast of Brazil. The best tilt angle was obtained for three selected periods. Additionally, we provide results for Southern latitudes ranging from 0° to −55° in steps of −5° for the meteorological seasons. We have shown that for each period, there is an increase in solar radiation absorption compared to the traditional installation angle based exclusively on the local latitude. These calculations can be extended to any location.


2019 ◽  
Vol 48 (3) ◽  
pp. 799-805 ◽  
Author(s):  
Jialong Duan ◽  
Qunwei Tang

The integration utilization of solar energy and waste energies by photovoltaics is regarded as a promising solution to resolve energy crisis and environmental pollution problems.


2019 ◽  
Author(s):  
Ni Li ◽  
Arianna Fatahi ◽  
Dennis Lee ◽  
Jim Y. Kuo ◽  
He Shen

Abstract In comparison to fossil fuels, solar energy is a more sustainable option due to its high availability and less environmental impact. Improving the efficiency of solar farms has been a primary concern of solar energy research. Many studies focus on the control of the tilt angle of solar modules to maximize their solar radiation reception and energy generation. However, an increase in solar radiation is accompanied by an increase in module temperature, which is known to be a significant parameter that reduces the power generation efficiency. Wind is another influential factor that helps Photovoltaic systems maintain a low operating temperature by enhancing the rate of heat transfer. Therefore, solar radiation and wind behavior are both critical parameters that must be considered to optimize solar panel performance. In this paper, the effect of wind conditions on solar panel performance will be examined. The solar panel energy output model will be built by empirically considering the irradiation, ambient temperature, wind speed, and wind direction. The published weather data and energy output data for the year 2017–2018 have been collected from Antelope Valley Solar Ranch, located in Lancaster, California. Four models have been proposed and the results indicate that the model which incorporates the wind conditions has the highest accuracy in approximating the energy production of solar farms. Among the factors that affect the temperature of solar panels and further the efficiency of solar panels including solar irradiation, convection, conduction, wind plays a major role in convective heat transfer. Based on this model, the potential improvement of energy generation via introducing a horizontal installation angle and adjusting this angle monthly according to the wind conditions is further analyzed. These results will help designers improve the design of solar farms by taking into consideration the local weather conditions.


2013 ◽  
Vol 1547 ◽  
pp. 115-119 ◽  
Author(s):  
J. E. Mathis ◽  
Z. Bi ◽  
C. A. Bridges ◽  
M. K. Kidder ◽  
M. P. Paranthaman

ABSTRACTTitanium (IV) oxide, TiO2, has been the object of intense scrutiny for energy applications. TiO2 is inexpensive, non-toxic, and has excellent corrosion resistance when exposed to electrolytes. A major drawback preventing the widespread use TiO2 for photolysis is its relatively large band gap of ∼3eV. Only light with wavelengths shorter than 400 nm, which is in the ultraviolet portion of the spectrum, has sufficient energy to be absorbed. Less than 14 percent of the solar irradiation reaching the earth’s surface has energy exceeding this band gap. Adding dopants such as transition metals has long been used to reduce the gap and increase photocatalytic activity by accessing the visible part of the solar spectrum. The degree to which the band gap is reduced using transition metals depends in part on the overlap of the d-orbitals of the transition metals with the oxygen p-orbitals. Therefore, doping with anions such as nitrogen to modify the cation-anion orbital overlap is another approach to reduce the gap. Recent studies suggest that using a combination of transition metals and nitrogen as dopants is more effective at introducing intermediate states within the band gap, effectively narrowing it. Here we report the synthesis of mesoporous TiO2 spheres, co-doped with transition metals and nitrogen that exhibit a nearly flat absorbance response across the visible spectrum extending into the near infrared.


Author(s):  
Shiwen Du ◽  
Juhong Lian ◽  
Fuxiang Zhang

AbstractPhotocatalysis based on semiconductors has recently been receiving considerable research interest because of its extensive applications in environmental remediation and renewable energy generation. Various semiconductor-based materials that are vital to solar energy utilization have been extensively investigated, among which titanium oxide (TiO2) has attracted considerable attention because of its exceptional physicochemical characteristics. However, the sluggish responsiveness to visible light in the solar spectrum and the inefficient separation of photoinduced electron–hole pairs hamper the practical application of TiO2 materials. To overcome the aforementioned serious drawbacks of TiO2, numerous strategies, such as doping with foreign atoms, particularly nitrogen (N), have been improved in the past few decades. This review aims to provide a comprehensive update and description of the recent developments of N-doped TiO2 materials for visible light-responsive photocatalysis, such as (1) the preparation of N-doped/co-doped TiO2 photocatalysts and (2) mechanistic studies on the reasons for visible light response. Furthermore, the most recent and significant advances in the field of solar energy applications of modified N-doped TiO2 are summarized. The analysis indicated the critical need for further development of these types of materials for the solar-to-energy conversion, particularly for water splitting purposes.


2018 ◽  
pp. 4-6
Author(s):  
Julian B. Aizenberg ◽  
Vladimir P. Budak

2017 has been a very productive and interesting year for our journal Light & Engineering/Svetotekhnika. It was marked by the publication of a large series of analytical reviews on the current state and prospects for the development of a number of important areas of lighting engineering (a total of 12 reviews), the publication of the regional volume of the Light & Engineering Journal (No. 3) devoted to solar energy technology in China (250 pages, 33 articles), further expansion of publications by international authors in Light & Engineering (since 2010, 120 articles by 230 authors from 23 countries have been published).


Author(s):  
B. Khadambari ◽  
S. S. Bhattacharya

Solar has become one of the fastest growing renewable energy sources. With the push towards sustainability it is an excellent solution to resolve the issue of our diminishing finite resources. Alternative photovoltaic systems are of much importance to utilize solar energy efficiently. The Cu-chalcopyrite compounds CuInS2 and CuInSe2 and their alloys provide absorber material of high absorption coefficients of the order of 105 cm-1. Cu2ZnSnS4 (CZTS) is more promising material for photovoltaic applications as Zn and Sn are abundant materials of earth’s crust. Further, the preparation of CZTS-ink facilitates the production of flexible solar cells. The device can be designed with Al doped ZnO as the front contact, n-type window layer (e.g. intrinsic ZnO); an n-type thin film buffer layer (e.g. CdS) and a p-type CZTS absorber layer with Molybdenum (Mo) substrate as back contact. In this study, CZTS films were synthesized by a non-vaccum solvent based process technique from a molecular-ink using a non toxic eco-friendly solvent dimethyl sulfoxide (DMSO). The deposited CZTS films were optimized and characterized by XRD, UV-visible spectroscopy and SEM.


Sign in / Sign up

Export Citation Format

Share Document