Page 31 - Advances in Renewable Energies and Power Technologies

4 CHAPTER 1 Solar Cells and Arrays: Principles, Analysis, and Design

5.6 The Flat Plate Modules.......................................................................... 42
5.7 Failure Modes of the Modules................................................................. 43
5.8 The Glassing Factor of the Module.......................................................... 44
6. Circuit and Device Simulation of Solar Cells and Modules...................................... 45
6.1 Circuit-Level Simulation ........................................................................ 45
6.1.1 Summary of Mathematical Modeling ................................................... 45
6.1.2 Parameter Extraction .......................................................................... 45
6.1.3 PSpice Model of the Solar Cell ............................................................ 46
6.1.4 Case Studies ...................................................................................... 48
6.2 TCAD Simulation of Solar Cells .............................................................. 49
6.2.1 Qualitative Analysis for the Novel npn Solar Cell Structure ................... 50
6.2.2 Construction of npn Solar Cell Structure Using Athena......................... 51
6.2.3 Electrical and Optical Characterization for the npn
Structure Performance........................................................................ 52
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6.2.4 The Simulation of the Effect of Different n Emitter Sidewall Surfaces
on the Electrical Performance ............................................................. 53
References ...............................................................................................................54
Further Reading ........................................................................................................56

1. INTRODUCTION
The main energy source in our earth is the sun radiation [1]. The solar radiation
amounts to 1.7 10 17 W; 34% will be reflected back, 42% will be converted to
heat directly, 23% is stored in water vapor, wind water waves consumes about
1%, and plants consume 0.023%.
The human consumption comes from fossil fuel, nuclear energy from uranium,
and geo heat. Any forms of energy are converted to heat and ultimately to radiation.
Till now, there is no appreciable direct conversion path from the solar radiation to the
human consumption. This is because:
• There is no efficient conversion machine till now,
• The solar radiation has a low density,
• The solar power is not constant. It varies daily, from season to season, and also
from place to place on the earth.

1.1 GENERAL PHOTOVOLTAIC SYSTEM
The photovoltaic (PV) system converts the solar radiation into electricity directly.
The block diagram of a general PV system is shown in Fig. 1.1.
It consists of the following building blocks:
1. The PVarray: Its function is the conversion of solar radiation into electricity. It is
the major unit in the system.