PV Cells

[Alan Combellack]

My apologies if these questions have been done to death but I am new to
this, and lazy
.. I know PV cells are claimed to be about 20% efficient, unless they are
very expensive. I assume this means that 20% of the incident light is
converted to electrical output. I am wondering about the relative areas of
actual collecting surface and the area blacked out by the support
structures. I hope a square metre of collecting panel area shadows only a
little more than 1 m^2. Can anyone advise me please?
The other "fact" I have seen is that PV cells now cost about $3.00 per
Watt of output power Is this calculated for a cell exposed to "full"
sunlight or to some arbitrary light level? TIA

Alan C
[email protected]

 

[Anthony Matonak]

My apologies if these questions have been done to death but I am new to
this, and lazy
. I know PV cells are claimed to be about 20% efficient, unless they are
very expensive. I assume this means that 20% of the incident light is
converted to electrical output. I am wondering about the relative areas of
actual collecting surface and the area blacked out by the support
structures. I hope a square metre of collecting panel area shadows only a
little more than 1 m^2. Can anyone advise me please?
The other "fact" I have seen is that PV cells now cost about $3.00 per
Watt of output power Is this calculated for a cell exposed to "full"
sunlight or to some arbitrary light level? TIA

Most PV cells are around 12-15% efficient and this drops to around
10-12% due to heat when used in the real world. Output is measured
using standard test conditions (STC) which is approximately equal
to full sunlight. Typically the panels will produce roughly 80-85%
of this number in the real world. Most framing on PV panels cover
less than a couple percent of the panel area and $3.00/Watt would
be kind of tough to find in todays market. Demand has far outpaced
supply so you'll likely be looking at $4.50 to $5.00/Watt.

Anthony

 

[Alan Combellack]

Thank you very much Sir. I seems that large scale use of PV still is far
from economically viable as a replacement for fossil fuel. This won't last
for ever though as the fossil fuels will get ever more expensive and will
all be used up anyway. I guess I am becoming a bit of a fanatic but I don't
think that we, as a society, are investing anywhere near sufficient brains
and resources on figuring out how to live adequately from incoming sunlight.
In addition to the power problem we must be approaching the limit of food
production for the population as well.
Alan C