Comparison between the characteristics of wind power calculations and solar radiation energy of some meteorological stations in Iraq

1987 ◽  
Vol 4 (4) ◽  
pp. 513-516 ◽  
Author(s):  
S.I. Al-Azzawi ◽  
N.A. Zeki
2018 ◽  
Vol 20 (5) ◽  
pp. 321-323
Author(s):  
Sh. Payziyev ◽  
Kh. Makhmudov ◽  
S. Bakhramov ◽  
A. Kasimov

On the basis of the active element of Ti3+:Al2O3, the possibility of converting solar energy into laser radiation energy is investigated. By the computer simulations, it was shown the possibility of reducing the threshold pump power by choosing the optimal geometry of the crystal parameters for end-pumping scheme of concentrated solar radiation.


2008 ◽  
Vol 14 (4) ◽  
Author(s):  
LE Akpabio ◽  
AB Udoimuk ◽  
SE Etuk ◽  
I Essien ◽  
NE Ituen

2010 ◽  
Vol 18 (3) ◽  
pp. 188-195 ◽  
Author(s):  
Algimantas Sirvydas ◽  
Vidmantas Kučinskas ◽  
Paulius Kerpauskas ◽  
Jūratė Nadzeikienė ◽  
Albinas Kusta

Solar radiation energy is used by vegetation, which predetermines the existence of biosphere. The plant uses 1–2% of the absorbed radiant energy for photosynthesis. All the remaining share of the absorbed energy, accounting for 99–98%, converts into thermal energy in the plant leaf. At the lowest wind under natural surrounding air conditions, plant leaves change their position with respect to the Sun. An oscillating plant leaf receives a variable amount of solar radiation energy, which causes changes in the balance of plant leaf energies and a changing emission of heat in the leaf. The analysis of solar radiation energy pulsations in the plant leaf shows that when the leaf is in the edge positions of angles 10°, 20° and 30° with respect to the Sun, 1.5%; 6% and 13% less of radiation energy reach the leaf, respectively. During periodic motion, when the amplitude of leaf oscillation is no bigger than 10°, the plant surface receives up to 1.6% less of solar radiation energy within a certain period of time, and when the amplitude of oscillation reaches 30° up to 14% less of solar radiation energy reach the leaf surface. The total amount of radiant energy received during pulsations of solar radiation energy is not dependent on the frequency of oscillation in the same interval of time. Temperature pulsations occur in the leaf due to solar radiation energy pulsations when the plant leaf naturally changes its position with respect to the Sun. Santrauka Saules spinduliuotes energija būtina augalijai, kuri lemia biosferos egzistavima. Augalas 1–2 % absorbuotos spinduliuotes energijos sunaudoja fotosintezei, o 99–98 % absorbuotos energijos augalo lape virsta šilumine energija. Natūraliomis aplinkos salygomis esant mažiausiam vejui augalo lapu padetis Saules atžvilgiu keičiasi. Taigi augalo svyruojančio lapo gaunamas Saules spinduliuotes energijos kiekis yra kintamas, tai sukelia pokyčius augalo lapo energiju balanse ir kintama šilumos išsiskyrima lape. Analizuojant Saules spinduliuotes energijos pulsacijas augalo lape, nustatyta, kad, lapui esant kraštinese 10°, 20° ir 30° kampu padetyse Saules atžvilgiu, i ji atitinkamai patenka 1,5 %; 6 % ir 13 % mažiau spinduliuotes energijos. Augalo lapui periodiškai svyruojant, kai svyravimo amplitude yra iki 10°, per tam tikra laika i lapo paviršiu patenka iki 1,6 % mažiau Saules spinduliuotes energijos, o kai svyravimo amplitu‐de siekia iki 30°, – iki 14 % mažiau. Saules spinduliuotes energijos pulsaciju metu gautas bendras spinduliuotes energijos kiekis nepriklauso nuo to paties laiko intervalo svyravimo dažnio. Del Saules spinduliuotes energijos pulsaciju, natūraliai keičiantis augalo lapo padečiai Saules atžvilgiu, lape kyla temperatūros pulsacijos. Резюме Растения потребляют солнечную лучевую энергию, которая является основой существования биосферы. 1–2% абсорбированной лучевой энергии они используют на фотосинтез. В натуральных условиях при малейшем дуновении ветра листья растений меняют свое положение относительно Солнца. Колеблющийся лист получает переменное количество лучевой энергии, которое вызывает изменения в энергетическом балансе листа растения, что сказывается на переменном выделении тепла в листе. Анализируя пульсации солнечной лучевой энергии в листе растения, установлено, что при крайних положениях листа относительно Солнца на 10, 20 и 30 градусов на лист попадает соответственно на 1,5%, 6% и 13% меньше лучевой энергии. При периодическом колебании листа, когда амплитуда его колебания составляет 10 градусов, за известный промежуток времени солнечная лучевая энергия, попадающая на поверхность листа, уменьшается до 1,6%, а при амплитуде колебания до 30 градусов соответственно количество лучевой энергии на поверхности листа растения уменьшается до 14%. Установлено, что суммарное количество солнечной лучевой энергии во время пульсации не зависит от частоты колебания листа за одинаковый промежуток времени. Пульсации солнечной лучевой энергии при изменении положения листа растения относительно Солнца вызывают температурные пульсации в листе.


2014 ◽  
Vol 935 ◽  
pp. 97-101
Author(s):  
Zhen Zhong Guan ◽  
Chong Jie Wang ◽  
Yi Bing Xue

A solar district heating and water heating integrated system has been designed and installed in a 5000m2 residential quarter. The integrated system uses vacuum glass tube solar collector to collect solar radiation energy, and uses water as heat medium. Solar energy provides almost 50% of the total heating energy consumption in winter. The inadequate part of energy can be provided by a steam heater which steam is provided by exhaust steam of the turbine from a power station nearby. The integrated system is operating automatically according to the solar radiation and working condition. Low-temperature floor radiation system is used as indoor heat radiator. At the same time, the system can provide 24h hot water supply. The integrated system has operated for 3 years, saves a large amount of energy, and receives good profit in both economical and environment.


2014 ◽  
Vol 592-594 ◽  
pp. 2404-2408 ◽  
Author(s):  
Sunita Meena ◽  
Chandan Swaroop Meena ◽  
V.K. Bajpai

Solar energy collectors are a special kind of heat exchangers that transform solar radiation energy to internal energy of the transport medium. The major component of any solar system is the solar collector. This is a device which absorbs the incoming solar radiation, converts it into heat, and transfers this heat to a fluid (usually air, water, or oil) flowing through the collector. The measurement of the flat plate collector performance is the collector efficiency. The collector efficiency is the ratio of the useful energy gain to the incident solar energy over a particular period of time. The useful energy gain is strongly depends on the collector efficiency factor and this factor directly influenced by few parameters i.e. the centre to centre distance of absorber tubes W , thickness of absorber plate δ and heat loss coefficient UL. This paper has been focused on the relation between W with collector efficiency factor of serpentine tube solar flat-plate collector. This study shows that if we increase the W then Fˈ decreases.


2015 ◽  
Vol 70 (3) ◽  
pp. 177-184 ◽  
Author(s):  
Tariq Hussain ◽  
Tasawar Hayat ◽  
Sabir Ali Shehzad ◽  
Ahmed Alsaedi ◽  
Bin Chen

AbstractThe flow problem resulting from the stretching of a surface with convective conditions in a magnetohydrodynamic nanofluid with solar radiation is examined. Both heat and nanoparticle mass transfer convective conditions are employed. An incompressible third grade fluid which exhibits shear thinning and shear thickening characteristics is used as a base fluid. Concept of convective nanoparticle mass condition is introduced. Effects of Brownian motion and thermophoresis on magnetohydrodynamic flow of nanofluid are accounted in the presence of thermal radiation. Energy equation incorporates the features of Joule heating. The impact of physical parameters on the temperature and nanoparticle concentration has been pointed out. Numerical values of skin-friction coefficient are presented and analysed. It is hoped that this present investigation serves as a stimulus for the next generation of solar film collectors, heat exchangers technology, material processing, geothermal energy storage, and all those processes which are highly affected by the heat enhancement concept.


2013 ◽  
Vol 18 (4) ◽  
pp. 209-214
Author(s):  
Chan Ho Jeong ◽  
Jin Woon Lee ◽  
Yong-Jun Jang ◽  
Jooheon Kim ◽  
Hong Sun Ryou ◽  
...  

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Patrick T. Brown ◽  
David J. Farnham ◽  
Ken Caldeira

AbstractWind and solar electricity generation is projected to expand substantially over the next several decades due both to rapid cost declines as well as regulation designed to achieve climate targets. With increasing reliance on wind and solar generation, future energy systems may be vulnerable to previously underappreciated synoptic-scale variations characterized by low wind and/or surface solar radiation. Here we use western North America as a case study region to investigate the historical meteorology of weekly-scale “droughts” in potential wind power, potential solar power and their compound occurrence. We also investigate the covariability between wind and solar droughts with potential stresses on energy demand due to temperature deviations away human comfort levels. We find that wind power drought weeks tend to occur in late summer and are characterized by a mid-level atmospheric ridge centered over British Columbia and high sea level pressure on the lee side of the Rockies. Solar power drought weeks tend to occur near winter solstice when the seasonal minimum in incoming solar radiation co-occurs with the tendency for mid-level troughs and low pressure systems over the U.S. southwest. Compound wind and solar power drought weeks consist of the aforementioned synoptic pattern associated with wind droughts occurring near winter solstice when the solar resource is at its seasonal minimum. We find that wind drought weeks are associated with high solar power (and vice versa) both seasonally and in terms of synoptic meteorology, which supports the notion that wind and solar power generation can play complementary roles in a diversified energy portfolio at synoptic spatiotemporal scales over western North America.


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