
309Photovoltaics
© 2008 Taylor & Francis Group, LLC
or
V
kT
e
J
J
oc
o
s
o
ln 1
Figure 6.8 shows a typical performance curve (I−V) of a solar cell. The power output is the
product of the load current and voltage and is a function of the load resistance
LLL
=
2
(6.11)
where A is the area of the cell.
The power output exhibits a maximum. To nd the condition for the maximum power
output (P
max
), differentiate P with respect to V and equate it to zero:
exp
eV
eV
J
om om s
+
=+
(6.12)
where V
m
stands for voltage at maximum power. The current at maximum power condition
J
L,m
and the maximum power P
max
can be found from Equations 6. ...