Cell disposition

2. Ch-5: PhotoVoltaic Devices

3. PV Cell Types
• Crystalline Silicon – (c-Si)
Monocrystalline, Polycrystalline
• Thin Film
- Amorphous Silicon– (a-Si)
- Cadmium Telluride (CdTe)
- Copper Indium Gallium Disel. (CIGS)
- Perovskite Solar Cell
• Multi Junction
• Bifacial Cell
https://solarmagazine.com/solar-panels/bifacial-solar-panels/
DOE SETO: https://www.energy.gov/eere/solar/articles/pv-cells-101-primer-solar-photovoltaic-cell

4. U.S. Department of Energy (DOE) Solar
Energy Technologies Office (SETO)
Super-efficient solar cells – MIT Tech Review

5. I-V Characteristics of a Photovoltaic Cell
Ideal Cell

6. I-V Characteristics of a Practical Photovoltaic Cell
Power output

7. I-V Characteristics of a Photovoltaic Cell
Main Parameters that affect I-V
- Insolation
- Temp

8. PV Cell – Power Generator

9. From Cells to Modules
• Basic building block for PV applications is a module.
A typical module will have 30-60 cells in series
V-I curve for a module having 36 cells in series

10. PV rating & Standard Test Conditions (STC)
STC:
Insolation s: 1-sun (1 kW/m2), spectral density with AM1.5, 25oC cell temp.
• Rating Data:
• Rated power: max power under STC
•V-I curve is given under STC
• Efficiency:

14. PV Module Economics

15. Power output under different operating conditions
 As insolation drops, short-circuit
current drops in direct proportion.
 Decreasing insolation reduces
open-circuit voltage marginally
Sharp ND-224U2
• Insolation

16. • Impact of Temperature
I-V characteristic curves
under various cell temperatures
Approach: use sensitivity
For silicon cell:
- Voc drops 0.37% per oC

17. • Impact of Temperature
I-V characteristic curves
under various cell temperatures
Approach: use sensitivity
For silicon cell:
- Pmp drops 0.5% per oC

18. • Estimating Cell Temp
To calculate cell temp at different ambient temp:
 Nominal Operating Cell Temperature (NOCT)
is given at 20oC ambient temp, and 0.8 sun.
Cell Temperature at other ambient temp:
S : Insolation

19. Eg: 150 W c-Si module, NOTC 47o
C
Calculate Pmp @ 30o
C and 0.5 sun

20. Effect of Shading
When a cell is shaded Isc = 0
-> when a cell in a module gets shaded it becomes reverse biased
Eg: Effect of a shaded cell in a 36 cell module: