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Materials: Abundance, Purification,

and the Energy Cost Associated

with the Manufacture of Si, CdTe,

and CIGS PV

Ajay Gupta

EROI ENERGY ADVISORS INC., BRAMPTON, ON, CANADA
akg78002@me.com

23.1 Introduction
“We’re made of star stuff,” Carl Sagan explained decades ago in his iconic television show
Cosmos. It is theorized that during the Big Bang the lightest elements—hydrogen, helium,
and trace amounts of lithium and beryllium—were formed. As stars form even today,
their cores fuse hydrogen into helium, and then when they begin to die they manufac-
ture carbon from fusing helium atoms. Very massive stars begin a further series of reac-
tions forming oxygen through iron (Fe). The most massive stars die in a supernova, which
releases enough energy and neutrons to form elements heavier than Fe, such as uranium
and gold (Au). Today we have identified 90 such naturally occurring elements and in total
119 elements are known to man. On Earth we have found methods of extracting, refining,
and using every material found for our increasingly complex industrial society [1,2]. These
materials not only make today’s industry possible; they are also what will make tomor-
row’s industry a reality.
The world is currently in a state of transition and the shift from fossil fuels to renew-
able technologies will lead to greater consumption of certain essential materials [3–6].
Although much attention is being paid to the decrease in coal mining across the globe,
almost no attention is being paid to the implications of growing demand for materials
required in renewable energy technologies. Renewable forms of energy and specifically
low or zero-carbon forms of energy are being sought to fulfill future needs in the face of
depleting fossil fuels and climate change. Photovoltaic (PV) energy is one of these renew-
able forms of energy and although implications of the economic and energy availability of

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