This page contains a Flash digital edition of a book.
APPLICATION
In general, PV materials are categorized as either Graph shows
crystalline or thin film, and they are judged on two Dramatic reduction in
basic factors: efficiency and economics. For battery capacity as
remote installations where the actual space temperature drops
available for PV panels is often quite limited, the
greater conversion efficiency of crystalline
technology seems to have the advantage. It is also
worth noting that the conversion efficiency of thin-
film panels tends to drop off rather rapidly in the
first few years of operation. Decreases of more
than 25% have been reported. However, there are
still applications where the lighter weight and
greater flexibility of the thin-film panels may be
more suitable and the parameters are improving
year to year.
Monocrystalline silicon panels should be utilized
when a higher voltage is desirable. This would be
in an instance where the DC power has to travel
some distance before being utilized or stored in a applications. Regardless of the technology
27
battery bank. These panels are also the most employed, the researcher would be well advised to
efficient PV technology, averaging 16% to 25%. look for modules with heavy-duty aluminum
www
New technology charge controllers, which allow for frames, UL ratings, easy-to-use junction boxes,
.solar
a higher array voltage than the battery bank and a long warranty (20+ years). All of these are
voltage, somewhat obviate the advantages of the indicative of a quality unit that will withstand the
-pv-management.com
monocrystalline panels. Polycrystalline silicon rigors of the polar environment.
panels have efficiencies of 12% to 18% and can
often be purchased at a lower cost per watt than Batteries
monocrystalline silicon panels. This type of panel The principal problem to overcome with any PV
sees the widest use in polar applications. system is that the sun does not shine on every part
of the planet with equal intensity. This uneven
Thin-film technologies include amorphous silicon, availability of solar energy is greatly exacerbated in
Issue I 2010
cadmium telluride, copper-indium di-selenide, and the Polar Regions. Daily and annual fluctuations in
others. Although the cost of these panels appears solar insolation necessitate storing excess energy
attractive at first, it is important to note that the for later use. Batteries are the technological
efficiencies are comparatively low. The 8% to 15% solution most commonly employed for this
efficiencies seen in new panels quickly degrade to
about 3% to 6% after several months of exposure
to sunlight. Furthermore, amorphous silicon and
cadmium telluride modules are sensitive to a much
narrower band of colors, and the winter shift to
redder sunlight results in slightly poorer
performance. Newer, triple-junction thin-film
technologies appear to have higher efficiencies
and less degradation over time, but they are still
subject to the same problems mentioned above, if
to a lesser degree.
The somewhat flexible nature of thin-film
technology may make it appropriate for some
applications, but in general, the higher efficiencies
and more robust nature of the crystalline silicon
modules make them a better choice for polar
Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61
Produced with Yudu - www.yudu.com