3.003 Principles of Engineering Practice
CdTe in Grid Connected Systems
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ANALYSES:
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Cost is the key constraint because the area
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available for grid connected systems is not limited
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Q
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Use low-cost photovoltaics
to increase the growth
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of grid connected systems
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Production of CdTe is high throughput (because of
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TheZ+*,6+58,-A
US energy
crisis
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necessitates the growth of its
solar cell market.
vapor transport deposition & automation) & low
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• Growth
rate of Grid-Tied PV
[=)<<"
Additions is over 40%
• Top US producer: FirstSolar (CdTe)
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MODULE COST
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issues
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Minimizing Manufacturing#$%&F"a>+534
Cost.
CdTe solar cell producers
(FirstSolar!7+!,#8-)$+!(3-&(/& Abound Solar) have
manufacturing costs of less than
$1/watt.
Improving Cell Efficiency.
Average efficiencies (~10%) are
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less
S56+/" than theoretical (20%).
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T+B+A.>:+58"
Efficiencies are also less than
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commercial silicon cells (20%)W.5*8/7@8,.5"!\"
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consequences
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cost
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#.A-/"$5+/09"W+58+/"-56"82+";DCGH-@"X#$"YA982+"K7:>+6"82+"DLC
GH-@"P+AA,*"&,/"X./@+"Y-*+",5*8-AA-8,.5",58."82,/6">A-@+)"
HOW IT WORKS (MODELS):
Improve
!,()-+.-)&(/-*+
CdTe cell design to maximize efficiency:
glass, TCO: tin oxide (also functions as !
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antireflective coating), cadmium sulfide (n-type),
3/,@+*"2-B+"?-AA+5"8."[D)OQC[;);Q">+/"(-88"?/.:"[N)Q<C[L)<<">+/"(-88"
cadmium telluride (p-type),
back
electrical
\
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,5":,6C;<<OF"-"6/.>".?".B+/"L<">+/@+58)
contact, glass
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Promote mass production of CdTe cells within the
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O
US with financial incentives
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ASSUMPTIONS AND LIMITATIONS:
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8."@.58,57+)"34",*"K+@.:,50"-5",5@/+-*,50A9"-88/-@8,B+"-56"*+@7/+"
• Continued exponential growth of solar
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manufacturing capacity (30%)
• Sales of solar cells produced in US only domestic
0"'$+$#+123-)$+(/+4565+
• Increasing tellurium costs don’t discourage growth
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of CdTe companies
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+U>+@8+6"8."0/.("*,05,?,@-58A9F"(,82":./+"82-5"!F<<<"GH",5"
• Use of government subsidies to encourage
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growth of manufacturing & sales
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:++8"82+"*8-/8C@.5*8/7@8,.5"6+-6A,5+".?"T+@+:K+/"NDF";<D<)"G.*8"
,567*8/9"-5-A9*8*"+U>+@8"-5.82+/"9+-/".?"0/.(82",5"82+"34",567*8/9)"
recommendations
@0
background
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Land displacement.
Acquisition of land necessary
for grid connected systems
may displace homes or
nature reserves.
Increased mining.
Expanded needs of cadmium
& tellurium may have
negative impacts around
areas of new mines.
Bankruptcy of other cell
manufacturers. Growth of
CdTe manufacturers might
push manufacturers of other
cell types out of the market.
OVER 3300 GW FROM
SOLAR ENERGY IN 50
YEARS POSSIBLE
Implement CdTe
photovoltaics for use in grid
connected systems
• Offer financial incentives for
CdTe manufacturers & consumers
• Invest in the research &
development of CdTe cells
The deployment of CdTe cells for grid systems can help solve the current US energy crisis!
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3.003 Principles of Engineering Practice
Spring 2010
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