ekonomija

energijaTable 2 Feed-in-tariffs for PV solar energy in some European countries,[1]. The installed “peak” power of solar power station is given inkWp.get the PV power energy sector movingfurther and faster, unless there isno intention to remove a lot of otherobstacles (administrative, educational,for example), to provide the additionalsupport including financial one(loans, taxes) and if government failto improve FITs conditions if theirimplementation are not successful inpractice.Amongst other activities of Serbiangovernment, related closely to FITsinitiative, is the adoption of the Europeanrenewable energy Directives2001/77/EC, 2003/30/EC and specially2009/28/EC aimed to improve the renewableenergy share to 20 % in totalEU energy consumption - up to 2020.A year ago, Serbia has contributed tothe significant international politicalimpetus as the founder member ofthe International Renewable EnergyAgency (IRENA).6. Some Practical Data andConsiderationsAn average power of the sun irradianceat the earth surface is about 1000W/m 2 . The Sun irradiance can varyfrom season to season, from year toyear, but it is mainly dependable onthe geographic latitude. More precisely,a square metre of horizontalEarth surface receives, under Serbiangeographic and climatic conditions,between 1200 kWh/m 2 in the northto 1500 kWh/m 2 in the south solarirradiance annually (on average 1400kWh/m 2 ), which is a daily average ofabout 3.5 kWh/m 2 . In southern Europethe annual irradiance can reach up to1800 kWh/m 2 (Spain) and in northernEurope the irradiance drops to alow of 700 kWh/m 2 (Norway). Directsolar irradiance is about 50% and theremainder is diffuse irradiance fromthe atmosphere.Table 3 Prices of some solar modules (panels), made by the world’s largestPV manufacturers, in January 2010.[064]Module efficiencies of the state-of-theart market available solar panels arein the range 12 to 17%. So, a simplecalculation shows that 1kW of installedPV power requires area of about 7 to8 m2 (around 2.75m x 2.75m the squareshaped solar module array).The energy payback time of the PVmodules is an important property ofsolar systems. Energy payback time(EPBT) is defined as the time thePV module has to operate in order torecover the energy consumed for itsproduction (i.e. to recover the installationcosts). EPBT differs for PVmodules made by different technologiesand for complete installed PVsystems, and from country to country.For mono- and multicrystalline cells,EPBT for complete PV systems, inGermany for example, is between 6and 8 years, but for CdTe PV systemsis less than 3 years.The lifetime of the PV modulesdepends on the used technology aswell. For mono- and multicrystallinesilicon solar cells, most manufacturersgive a warranty of 10 / 90 and 25 / 80,which means: 10 years warranty thatthe module will operate above 90%of nominal power and up to 25 yearswith above 80%. Practical lifetime ofthe silicon-made PV modules could beexpected to be at least 30 years. Forthe newer thin-film technologies, tenyear guarantees are customary, but theexperiences with them are still limited.The grid-connected PV solar systemwith 1kW of installed PV power couldyields, under Serbian circumstances,on average: 1400 kWh x 0.23 1 /kWho± 320 1 /annualy. For the guaranteedperiod of 12 years it is nearly 4000 1.We explored the world’s PV market tocalculate the investment costs for 1 kWof PV power at the very beginning of2010. A lot of internet sites have beenbrowsed and investigated, as an examplehttp://www.brightgreenenergy.co.uk/ and http://www.pvsolarmodules.com/. Table 3. shows prices of somemarket available solar modules (panels),conversion rates (January 2010):=0.705, 1£/11 =1.125 have beenused. It is interesting to note that theUS solar cell seller internet sites areinforming their costumers that “solarmodules are in high demand in theEuropean market which makes themdiffi cult to obtain in the U.S.”. Manyof manufacturers and dealers chargeless 10 to 15% for several modulespurchased (e.g. more than 8 modules).Therefore, the installation price for 1kW of PV power has been found to