Environmental Engineering Reference
In-Depth Information
Table 8.1
Photovoltaic conversion efficiencies [108].
Junction type
Cell ef
ciency
Module ef
ciency
Dye-sensitized solar cells
8.2%
3
-
5%
Amorphous Si
(multijunction)
13.2%
6
-
8%
Cadmium telluride (CdTe)
thin
16.5%
8
12.8% (http://www.bizjournals.com/
denver/news/2011/04/07/ge-to-buy-solar-
panel-maker-primestar.html.)
-
lm
Copper
indium
gallium
19.9%
9
15.8% (http://www.semiconductor-today.
com/news_items/2011/SEPT/
AVANCIS_070911.html.)
-
-
-
-
selenides (CIGS)
Polycrystalline silicon
20.3%
12
-
15%
Monocrystalline silicon
23.4%
14
16%
-
High-performance mono-
crystalline silicon
24.7%
17
-
20%
Triple junction (GaInP/
GaAs/Ge) 250 suns
40.7%
Triple junction (GaInP/
GaInAs/Ge) 454 suns
41.1%
based on an advanced calculation. The authors point to a large literature related to
dilute magnetic semiconductors, which might be transferable to solar cell
applications.
8.4
Efficiencies: Three Generations of Cells
In discussing ef
ciency, it is useful to separate results on small laboratory junctions
and those in panels, arrays of junctions (as available) of size measured in meters
rather than centimeters. A summary of the most important solar cells and panel
types [108] is given in Table 8.1.
From the table one sees that the new concepts, beyond themultijunction cells, have
not reached the marketplace. The table is incomplete in that module ef
ciencies for
the SolFocus arrays of concentrating cells are not included. It appears that the
advanced organic tandem cells described in Section 7.1.3 have not entered the
market, while the dye-sensitized cells have done so, and are available also as panels.
The worldwide production of solar cells is reported 15.9GW in 2010 (http://
pvinsights.com/Report/ReportPMM04A.php.), with the top
ve producers (Sun-
tech, First Solar, Sharp, Yingli, and Trina Solar) each exceeding 1GW in production.
Of these companies, First Solar is a leader in producing CdTe panels based on thin-
film cells. The other
firms, mostly located in China, sell polycrystalline or mono-
crystalline Si panels. As we will see later, production overall is rapidly rising, with
most of these producers doubling their output in 2010 over the previous year.
