Energy yield I Unit 10

Transcription

1 Energy yield I Unit 10 Marcus Rennhofer marcus.rennhofer@ait.ac.at

2 Content Energy Yield Environmental parameters Irradiance Annual energy yield Generator quality measures Losses of energy Modelling Types of models Concepts of models Analytic models Statistic models Example of system efficiencies

3 ELWOG (Elektrizitäts-Wirtschafts-und-Organisations-Gesetz) Allows the owner of a PV-facility in a multi-family house to directly sell energy to others in the house.

4 1. Energy Yield

5 Solar spectrum Extra terrestrial Earth surface

6 Environmental parameters T a T m Ambient temperature [ C] Module temperature [ C] E, H, G Irradiance [W/m 2 ] E l RH p v w I SC Spectrally resolved E [W/m 2 nm] Relative humidity Air pressure Wind speed Short circuit current Further Radiation enhancement Cloudiness index Albedo UV-content

7 Distribution of irradiance Germany Site of facility has to be considered Technology choice South Italy 6th TFP Würzburg 2010, H.D. Mohring (ZSW)

8 Yield Irradiance Conversion Electric Yield

9 Yield 200 El [W/m 2 nm] SR (a.u.) Spectral Response SR(l) Irradiance E(l) l [nm] l [nm] I Ph ~ 4000 nm SR l E l dl 270 nm Monitoring! I SC, U OC, FF, P mpp, Y a 9

10 Composition of the irradiance on the tilted plane H D H B H R b E, G, H Irradiance [kwh/m 2 ] Direct Irradiance Diffuse Irradiance Reflected (diffuse) Irradiance

11 Yield on the tilted plane: reminder

12 2-axial tracking Without tracking Ya 2-axial tracking + 40 %

13 Energy Yield Definition: Irradiance Facility size El. Energy

14 Energy-Yield Y F = t vo = E a P G0 [ kwh/kwp a ] = [ h/a ] full load hours Ea = annual energy yield (EAC fed into the grid) P G0 = PV nominal generator power

15 Energy-Yield: Different Technologies type full load hours [h] Photovoltaic free field 1000 Photovoltaic facade 650 Photovoltaic desert 2000 Wind power onshore 2000 Wind power offshore 3000 Hydro power (Danube river) 6000 Nuclear / brown coal 8000

16 Yield Quality of generators Generator yield Radiation yield (Reference yield) Y A = E DC P G0 Y R = H G G 0 E a = Generator yield DC H G = irradiated energy (kwh /m2) G 0 = STC irradiance (1kW/m2) Generator losses L C = Y R Y A Inverter ultilization ratio DC to AC n l = Y F Y A Performance Ratio PR = Y F Y R

17 Losses: Optical 100% Air Solar glass ~ 1 % absorption 96% 95% ~ 4 % reflection % ~ 4 % reflection: with coupling 0% Solar cell

18 Ohmic losses What is the maximum length of a 6mm 2 PV-cable, in order to keep the ohmic losses below 1% for y system voltage of 100V? Specific resistance [ mm 2 /m] R = * L / F = 1/ L: Length, F: area : el. conductivity Voltage of system: U = R *I U = (L* I) / ( * F) L = 0.5 * ( 0.01 *U* * F) / I with: U =100 V, F = 6 mm 2, I ~ 6 A, (Cu) = 56 m / mm 2 L = 23 m

19 Ohmic losses A M 2 x L 1% U M x I MPP ST x k

20 Shading Shading diagram (manual or automated)

21 Shading of close objects Optimal distance to Pv generator Distance to sun (150. Mio km) Distance of shading object to PV Diameter of sun Diameter of of shading object

22 Shading of PV plant by itself sin d b x (180 b ) sin

23 2. Modelling

24 Models types Photovoltaic Models Time step- Models Homer PVSyst PVSol Analytical Models INSEL TRNSYS Empiric models Reference days Matrix model Statistic model

25 By-Hand calculation Häberlin, Photovoltaik 2007

26 Time step models DESIRÉ PV-SYST PV-GIS PV-Sol Polysun Meteonorm

27 Model: PV-Sol

28 Empiric models Reference days

29 Empiric models Reference days not sufficient

30 Analytic Models: INSEL

31 Statistic Models: Gerda Schubert, ISE

32 Statistic Models: Gerda Schubert, ISE

33 Statistic Models: Gerda Schubert, ISE

34 Example for System efficiency PV-electricity E-Mobility

35 Example for System efficiency Use case : PV-electricity electrolysis Low temperature fuel-cell Hydrogen-car 3-5 EUR / 100km

36 Example for System efficiency

37 VISIT AIT-Laboratory PVS Arrival by: Subway U6 (floridsdorf) + S-Bahn (Siemensstrasse) Subway U1 (Kargraner Platz) + 31A (Heinrich von Buol Gasse)

38 Thank you for your Attention!