Environmental Engineering Reference
In-Depth Information
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fig. 13.5
Solar ef
ciency map. Effective hours of sunlight
per year on a
flat plate collector including weather effects.
(Source: US Department of Energy
'
s Energy Ef
ciency
and Renewable Energy Division)
longer exists. It became bankrupt when the cost of con-
ventional PV cells dropped more than twofold in a few
years as China got into large-scale PV cell manufacturing.
There is still much development of advanced systems
occurring and we shall see in the future what, if anything,
will replace the conventional PV cell.
PV installations are increasing rapidly, though from a
small base. In the United States, California has the most
aggressive program with a goal that its Governor calls
“
a
million solar roofs.
GW.
However, just as with wind, there is a difference between
capacity and output, this time driven by day
”
The aim is a capacity of
-
night and
cloud cover.
Figure
] shows
the effective annual hours of output all over the United
States (including both latitude and weather effects). There
.
from the US DOE [
