Environmental Engineering Reference
In-Depth Information
Solar cell
Bypass
diode
Bypass
diode
Figure 4.26
Integration of Bypass Diodes across Single Cells or Cell Strings
Bypass diodes are usually connected across strings of 18-24 cells. The
reason for this is mainly economic. Two bypass diodes are sufficient for a solar
module with a rated power of about 50 W containing 36-40 cells. The diodes
can be integrated into the module frame or module junction box. However,
these diodes cannot fully protect every cell; only the use of one bypass diode
for every cell can provide optimal protection. Semiconductor technology can
integrate bypass diodes directly into the cells (Hasyim et al, 1986).
Shading-
tolerant modules
with cell-integrated bypass diodes, which were first
manufactured by Sharp, show significantly lower losses when they are
inhomogenously irradiated.
Figure 4.27
Simulation of Module Characteristics with Bypass Diodes across
Different Numbers of Cells (
E
= 1000 W/m
2
,
T
= 300 K)
