Environmental Engineering Reference
In-Depth Information
fig. 13.4
Rooftop photovoltaic system. A Solyndra CIGS
rooftop installation. (Courtesy of Solyndra, Inc.)
cost of a space project. Development has been continuous
since the early days and there are now many kinds of cells
of varying cost and ef
ciency. It is unfortunately true that
the cheaper the cell the lower the conversion ef
ciency
from sunlight to electricity, but even so the cost of elec-
tricity from solar cells has come down greatly from the
early days.
Technical Note
has a brief discussion of
how solar cells work and the types and ef
.
ciencies of cells
in use.
Most of the installations so far have been of the stand-
ard silicon solar cell roof panels, but there is lots going on
in the industry and new kinds of systems are being intro-
duced.
Figure
.
is an example of something different: a
CIGS
diselenide) system
developed by Solyndra Corporation. The elements are
like long
(cadmium
-
indium
-
gallium
-
fluorescent light tubes with another tube inside
coated with the PV material. Its advantages were some-
what higher output for the same area, and great ease in
installation. Unfortunately for its owners, Solyndra no
