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Solarna energija – U Suncu je budućnost

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Slobodan Miskovic

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icon Re: Solarna energija – U Suncu je budućnost02.09.2010. u 11:52 - pre 165 meseci
Isplativost tog sistema u Srbiji pri sadasnjim i projektovanim cenama struje u narednom periodu je veoma mala.

Sve dok u Srbiji struju placamo po povlascenim cenama alternativni izvori energije ce biti zastupljeni u promilima...
 
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eloiza

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icon Re: Solarna energija – U Suncu je budućnost02.09.2010. u 14:25 - pre 165 meseci
Citat:
Slobodan Miskovic: Isplativost tog sistema u Srbiji pri sadasnjim i projektovanim cenama struje u narednom periodu je veoma mala.

Sve dok u Srbiji struju placamo po povlascenim cenama alternativni izvori energije ce biti zastupljeni u promilima....


Dokaži tu tvrdnju.

http://www.solarni.rs/primena.htm

http://www.opticom.co.rs/porta...rticle&id=56&Itemid=66

http://www.adriaticbb.hr/Solar/solar.htm

[Ovu poruku je menjao eloiza dana 02.09.2010. u 15:46 GMT+1]
 
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Slobodan Miskovic

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icon Re: Solarna energija – U Suncu je budućnost02.09.2010. u 14:43 - pre 165 meseci
Nema sta da se dokazuje, samo kalkulator u ruke. Evo dacu ti nekoliko smernica.

Prvo, treba uzeti u obzir cinjenicu da Srbija 75% elektricne energije dobije iz Obrenovca. Ta elektricna energija se proizvodi iz uglja koji opet drzava Srbije ne placa te samim tim moze da se vrlja sa cenama kako hoce, tj. kako je narodu odgovarajuce. Posto se ekonomsko stanje u Srbiji u narednih 10-15 godine nece znacajnije promeniti na bolje dolazimo do zakljucka da se ni struja nece placati po ekonomskoj ceni.

Kada ovo imamo u vidu a znamo kolicinu elektricne energije koja se dobija kroz iskoriscavanje sunceve i na to dodamo cenu instalacije dolazimo do zakljucka da je stepen isplativosti ugradnje takvog sistema kod nas jako mali. ROI ovoga jeste 15-20 godina, sto je mnogo ako u obzir uzmemo velicinu pocetnih ulaganja.

Evo ti cene struje u EU i uporedi sa cenama u Srbiji.

http://www.energy.eu/#Domestic
 
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bigvlada
bgd

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icon Re: Solarna energija – U Suncu je budućnost04.10.2010. u 09:28 - pre 164 meseci
Solar cells thinner than wavelengths of light hold huge power potential


September 27, 2010 By Louis Bergeron


This schematic diagram of a thin film organic solar cell shows the top layer, a patterned, roughened scattering layer, in green. The organic thin film layer, shown in red, is where light is trapped and electrical current is generated. The film is sandwiched between two layers that help keep light contained within the thin film.

(PhysOrg.com) -- Ultra-thin solar cells can absorb sunlight more efficiently than the thicker, more expensive-to-make silicon cells used today, because light behaves differently at scales around a nanometer, say Stanford engineers. They calculate that by properly configuring the thicknesses of several thin layers of films, an organic polymer thin film could absorb as much as 10 times more energy from sunlight than was thought possible.

In the smooth, white, bunny-suited clean-room world of silicon wafers and solar cells, it turns out that a little roughness may go a long way, perhaps all the way to making solar power an affordable energy source, say Stanford engineers.

Their research shows that light ricocheting around inside the polymer film of a solar cell behaves differently when the film is ultra thin. A film that's nanoscale-thin and has been roughed up a bit can absorb more than 10 times the energy predicted by conventional theory.

The key to overcoming the theoretical limit lies in keeping sunlight in the grip of the solar cell long enough to squeeze the maximum amount of energy from it, using a technique called "light trapping." It's the same as if you were using hamsters running on little wheels to generate your electricity - you'd want each hamster to log as many miles as possible before it jumped off and ran away.

"The longer a photon of light is in the solar cell, the better chance the photon can get absorbed," said Shanhui Fan, associate professor of electrical engineering. The efficiency with which a given material absorbs sunlight is critically important in determining the overall efficiency of solar energy conversion. Fan is senior author of a paper describing the work published online this week by Proceedings of the National Academy of Sciences.

Light trapping has been used for several decades with silicon solar cells and is done by roughening the surface of the silicon to cause incoming light to bounce around inside the cell for a while after it penetrates, rather than reflecting right back out as it does off a mirror. But over the years, no matter how much researchers tinkered with the technique, they couldn't boost the efficiency of typical "macroscale" silicon cells beyond a certain amount.


Eventually the scientists realized that there was a physical limit related to the speed at which light travels within a given material.

But light has a dual nature, sometimes behaving as a solid particle (a photon) and other times as a wave of energy, and Fan and postdoctoral researcher Zongfu Yu decided to explore whether the conventional limit on light trapping held true in a nanoscale setting. Yu is the lead author of the PNAS paper.

"We all used to think of light as going in a straight line," Fan said. "For example, a ray of light hits a mirror, it bounces and you see another light ray. That is the typical way we think about light in the macroscopic world.

"But if you go down to the nanoscales that we are interested in, hundreds of millionths of a millimeter in scale, it turns out the wave characteristic really becomes important."

Visible light has wavelengths around 400 to 700 nanometers (billionths of a meter), but even at that small scale, Fan said, many of the structures that Yu analyzed had a theoretical limit comparable to the conventional limit proven by experiment.

"One of the surprises with this work was discovering just how robust the conventional limit is," Fan said.

It was only when Yu began investigating the behavior of light inside a material of deep subwavelength-scale - substantially smaller than the wavelength of the light - that it became evident to him that light could be confined for a longer time, increasing energy absorption beyond the conventional limit at the macroscale.

"The amount of benefit of nanoscale confinement we have shown here really is surprising," said Yu. "Overcoming the conventional limit opens a new door to designing highly efficient solar cells."

Yu determined through numerical simulations that the most effective structure for capitalizing on the benefits of nanoscale confinement was a combination of several different types of layers around an organic thin film.

He sandwiched the organic thin film between two layers of material - called "cladding" layers - that acted as confining layers once the light passed through the upper one into the thin film. Atop the upper cladding layer, he placed a patterned rough-surfaced layer designed to send the incoming light off in different directions as it entered the thin film.

By varying the parameters of the different layers, he was able to achieve a 12-fold increase in the absorption of light within the thin film, compared to the macroscale limit.

Nanoscale solar cells offer savings in material costs, as the organic polymer thin films and other materials used are less expensive than silicon and, being nanoscale, the quantities required for the cells are much smaller.

The organic materials also have the advantage of being manufactured in chemical reactions in solution, rather than needing high-temperature or vacuum processing, as is required for silicon manufacture.

"Most of the research these days is looking into many different kinds of materials for solar cells," Fan said. "Where this will have a larger impact is in some of the emerging technologies; for example, in organic cells."

"If you do it right, there is enormous potential associated with it," Fan said.

Aaswath Raman, a graduate student in applied physics, also worked on the research and is a coauthor of the paper.

More information: http://www.pnas.org/

http://www.physorg.com/news204827475.html
 
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bjdarko

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icon Re: Solarna energija – U Suncu je budućnost13.12.2010. u 22:21 - pre 161 meseci
@Slobodan Miskovic

Solarna elektrana iz dana u dan postaje isplativija u Srbiji. A zašto? Uzrok treba tražiti u padu cene izrade solarnih modula, preciznije kroz odnos euro/Wp. Danas je cena oko 1-1.5 eura/Wp stim što to ne prolazi kroz trgovinske lance, uglavnom onaj ko ima fabriku on i gradi solarnu elektranu. Na primer, u Kikindi će Kinezi graditi solarnu elektranu od 30MW sa cenom od 75-105miliona evra. Ako se ima u vidu da je period sklapanja ugovora na samo 12 godina i subvenciona cena solarne energije 0.23euro/kWh uz cenu elektrane od 75miliona (za ovo postoji opravdanje jer amorfni solarni paneli su jako jeftini, stim da se ne zna zvanična cena za Kinu zbog cene rada) dobiće se ROI oko 9god. stim što je procentualno oko 3.4%/god. dok u Evropi je 8-10%/god. Da bi se dobile investicije u ovoj oblasti potrbno je samo povećati broj godina u ugovoru na 15 godina, kao što je u Portugalu, Sloveniji, Holandiji, itd., ili još bolje na 17 godina kada je zarada oko 90% od uloženog. Cela stvar se vrti oko tih procenata jer ako bi ih uložili u banku dobili bi na godišnjem nivou veću kamatu nego u našu solarnu elektranu. Povećati subvencionu cenu za solarnu struju sada kada je trend pada tih cena u Evropi zbog preopterećenja budžeta nije baš pogodno!

@bigvlada

Naravno, ovo je interesantno rešenje ali zalazi u oblast MEMS-a što u mnogome poskupljuje proizvodnju. Današnja tehnologija izrade solarnih panela i to kristalnih i polikristalnih ima jedan proces stvaranja reljefaste srukture koji zadovoljava tako da se okreću ka novijim materijalima i "multijunction" ćelija da bi uhvatili više svetla.
 
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sunfan
Vladimir Kujovic
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icon Re: Solarna energija – U Suncu je budućnost20.04.2012. u 14:40 - pre 145 meseci
mprokic,

Nijedan komentar na fantasticno resenje . Sam pravim jedan malo zahtevniji sistem solarnog vazdusnog kolektora gde se greje ili dogreva sanitarna ,sve u zavisnosti od kolicine energije. Sigurno ste videli taj sistem.
Topao vazduh prolazi kroz izmenjivac i preko njega se greje voda u bojleru. Sistem odavno poznat i u praksi dokazan u normalnim tj naprednim zemljama ( Nemacka, Danska,Svedska, Kanada ,Austrija, Francuska , Australija itd). Svedski nacinalni muzej se u odredjenom delu godine greje pomocu vazdusnih solarnih kolektora. takvih primera u svetu ima mnogo, ali djabe...provizije su najbitnije,koga briga .

eloiza
Sto se pasivnog sistema grejanja tice ,blagodet sam osetio na svojoj kozi napravivsi zimsku bastu. Napolju -6 , sunce, bez vetra izmerena tem.39 stepeni. Za sada primitivnim metodom ubacujem zagrejan vazduh u kucu i svakog suncanog dana moj djep je bogatiji. A nemora da bude i suncan ( ako je zracenje zadovoljavajuce) da bi u zimskoj basti bilo i 25 stepeni.
Ako Vam kazem da sam za ovu zimu potrosio 300 eur za grejanje( naravno nista bez bdpobre izolacije), 4m3 drva i ostalo struja( TP vazduh- vazduh)
Ima, onaj ko zna da ustedi ,a ne onaj koji zaradi.

Za sve skeptike , neupucene i nedovoljno informisane sledi iznenadjenje.

Kako solarni sistemi funkcionisu u daleko hladnijoj Austriji i Namackoj, pogledajte na sledecem sajtu www.solartirol.at. u meniju liveanlagen i livenanlagenlinks. Domacin je,kako ga zovem, nesebicno podelio iskustvo kako svoje tako i drugih Domacina, sa celim svetom . Primeticete da ucestvujete u njihovim sistemima u realnom vremenu i sa kompletnim analizama i troskovima.

Solarni sistemi mogu da se naprave za daleko manje novca . To sto smo lenji i ne zelimo sebi da pomognemo to je dreuga stvar.]

Tastaruma me malo izdaje, ako ima gresaka, izvinjenje.


Pozdrav SUNCU i svim ljudima dobre volje i namere
PR 85m2 8cm/20gr,malter,blok 19,5 k.vuna, p brana, cigla.Pod heraklit 7cm
Duž južne fas. zast. ter. ( cca 90m3 ), sa pasivno sol. grej.
Podno,f coil, radij., sušač
LG MAESTRO inv. 12
U aneksu garaža sa izol.5cm, plaf. g. 15 vuna. Krov PTK garaze 22 cm vuna
PTK cca 85m2 izol. kao PR. Krov 28 cm, pod 7 cm +sist.ploča za podno 5,5cm
Pos. brojilo,AT 1000 l+el.kotao + TP 18 kw vaz-voda
 
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mitarjelic
Mitar Jelic
nemam
nezaposlen
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icon Re: Solarna energija – U Suncu je budućnost18.11.2014. u 09:50 - pre 113 meseci
Objasnjenje kako rade solarni paneli možete pročitati ovde.
http://kako-rade-solarni-paneli.blogspot.com/
 
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