TASK 1

Romanian team: Şutu Oana Andrei BiancaRusu Ioana

Photovoltaic solar energy is the energy produced through photovoltaic cells, which convert the sunlight directly into electric energy.

Why photovoltaic energy? Because all human activities depend on electric energy; It is necessary to have an unconventional energy, renewable, easily

accessed and without high costs;The required primary energy of humanity in 2006 was 1.0 × 1014

kWh/year. The Sun provides approximately 1.1 × 1018kWh, so 13.000 more times than needed; In our city the idea of setting up a photovoltaic central, dates since

November 2009. Then it was approved the construction project of a photovoltaic plant with a power of 2.9946 MW;

The installations will occupy 3.6 hectares of land; The works began in May 2013; The bottom table shows the characteristics of the future plant. 

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Yet, in our city we have photovoltaic panels on:1. Private constructions,2. Public institutions (schools, kindergartens, polyvalent hall) etc.

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THE ADVANTAGES OF PHOTOVOLTAIC PLANTS

Long life time and functioning, approximately 25 years; Are depreciated over time, amortization period depends

on the technology used; Low running costs: The photovoltaic elements use

sunlight-free fuel; Ecological: do not consume fossil fuel, so do not pollute

the environment; Inexhaustible source; Technology without noise pollution. 4

Solved tasks1. Water power plant η =0.85(85%) ρ=103 kg/m3

Q=150m3/s g=9.81m/s2

h=100m P= η * Q *ρ *g*h P=0.85*150 m3/s *103kg/m3

*9.81 m/s2*102 m=125.0775·106

w P=125·106w - power of a 1

Francis turbine Ptotal=2·125 ·106w = 250·106w

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Photovoltaic panel - the power of solar radiation (in a sunny day) at the surface of the photovoltaic panel angled to 30 degrees it is 1000 W/m2. A voltaic park / photovoltaic plant of 10 km2 will have the power:Pf =1000 W/m2 *107 m2= 1010 wConclusion: Pf/ Ptotal=1010 w/ 250·106w = 40Photovoltaic plant provides 40 times more electric power than hydro plant for 10 km2. 

2. W=P*tThe energy W water power plant per year: 250*106w* 365 days*24 hours=219*106 kwhThe energy W photovoltaic plant per year: 1010 w* 365 days*24 hours= 8760 *106 kwh

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3.

The water power plant Stejaru (15 km of our city) it is powered by the waters of the biggest artificial lake arranged on the inland rivers. C ha r a c t e r i s t i c s : Stejaru central is semi air type and includes six generating groups of Czech manufacturing, with Francis turbines with vertical shaft: four turbines with a power of 27.50 MW and two turbines of 50 MW. debit -178 m3/sec, high -127 m surface, S – 310km2

the length of the lake-35 km width comprised- between 200 and 2000 m the maximum volume - 1250*109 m3 P installed =210 Mw 

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THE NEARLY PHOTOVOLTAIC PLANT:

PV Output: 1.001,88 kWp Gross/Active PV Surface Area: 7.093,96

/ 7.109,36 m² PV Array Irradiation: 10.201.141 kWh Energy Produced by PV Array (AC):

1.148.878 kWh Grid Feed-in: 1.148.878 kWh System Efficiency: 11,2 % Performance Ratio: 79,3 % Inverter Efficiency: 94,7 % PV Array Efficiency: 11,8 % Specific Annual Yield:1.138 kWh/kWp

The performance for m2:

The water power plant Stejaru:

W/m2 = (210*106w*365 days*24 hours)/310m2 = 1839600Kwh/310*103m2

= 5.93 Kwh/ m2

Photovoltaic plant: 1148878Kwh/ 7.109,36 m²=161.60 Kwh/ m2

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4. 10 km2 = 1000 hectares The medium production of wheat on hectare is 3.46 tones =>

for 10 km2 we have 3460 tones The medium production of corn for one hectare is 3.86 tones

=> for 10 km2 we have 3860 tones The medium production of potatoes is 15.12 tones => for 10

km2 is 15120 tones 

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