Geology Reference
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posits account for a total of 22.4 Mt (Uyuni Bolivia, brine, 10.2Mt, Atacama Chile,
brine 6.3 Mt and Kings Mountain Belt United States, pegmatite 5.9 Mt). There is
thus enough lithium available to cover demand throughout the 21st century. The
ocean also contains enormous amounts of lithium which cannot be extracted due
to issues relating to economic feasibility, as opposed to any real level of geological
scarcity.
A.3 Energy saving in lighting
Around 18-20% of world's electricity production is used for lighting, a sector which
is undergoing an important transition whereby traditional incandescent light bulbs
are rapidly being substituted worldwide by the more e
cient fluorescent types -
the compact (CFL) and the linear (LFL). According to IEA (2011a) a shift from
incandescent lamps to CFLs, as already has occurred in the EU following the phasing
out of non-unidirectional incandescent lamps (EC, 2008) would cut world lighting
electricity demand by 18%.
Whilst both generate definite energy savings, the problem with the e
cient
triband phosphor CFL and LFL is their rare earths content. A CFL contains
between 1.1 and 1.5 g of phosphor, which in turn is composed by the following
REE: La, 8.5%; Ce, 20%; Eu, 4.5%; Tb, 5% and Y , 62% (DOE, 2011). All are used
for fluorescent lamps and for liquid crystal displays. The first two produce visible
white light. Yttrium is used as a red phosphor for TV screens, while europium
activates yttrium-based phosphors in conventional television and LCD screens. All
elements due to their scarcity are consistently more expensive and show steep price
increases. Three of them: yttrium, terbium and europium have no known substitute
as phosphors.
CFLs do however offer, somewhat paradoxically, the opportunity for recycling
due to the small amounts of mercury that they contain (4.0 mg per bulb in av-
erage). This is something which could potentially open the door for phosphors
recycling too. Should recycling prove di
cult, an alternative to CFLs are the Light
Emitting Diodes (LEDs) which are even more energy e
cient and durable with a
rare earth content one or two orders of magnitude lower than that found in a CFL.
Unsurprisingly therefore, LEDs are rapidly substituting CFLs.
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