Energy Solutions to Air Pollution and Global Warming - Air Pollution and Global Warming: History, Science, and Solutions - page 331

13.6.5. Materials for Hydrogen Fuel
Cell Vehicles
The production of millions of HFCVs would increase
demand for platinum (Pt) used in fuel cells. However,
because HFCVs would replace gasoline and diesel vehi-
cles, many of which use Pt in catalytic converters, the
increase in Pt demand for HFCVs would be partly offset
by a decrease in Pt demand for combustion vehicles.
Because BEVs would comprise the largest share of
vehicles in a WWS world due to their high efficiency,
the number of HFCVs required would be limited. If
10 percent of the vehicle fleet were HFCVs, about
100 million 50-kW HFCVs might be needed in 2030.
These would require about 1.25 million kg Pt. The esti-
mated resource of Pt group metals in deposits world-
wide is more than 100 million kg (U.S. Geological Sur-
vey, 2011). Platinum group metals (PGMs) are six
elements - ruthenium (Ru), rhodium (Rh), palladium
(Pd), osmium (Os), iridium (Ir), and Pt - that have
similar physical and chemical properties and are often
found in the same deposits. The largest known deposit
of PGMs is in the Bushveld Igneous Complex of the
Transvaal Basin, South Africa. Other large deposits are
near Norilsk, Russia, and Sudbury, Canada. Pt com-
prises at least one-sixth of total PGM deposits; thus, Pt
resources should be much larger than the Pt needed for
vehicles. In addition, Pt is already recycled, and addi-
tional Pt will be available due to the reduced need for
Pt in catalytic converters upon conversion to WWS. As
such, Pt is not considered a limiting element in a WWS
economy.

Table 13.6. Lithium resources by country, as of
2011 (million metric tonnes)

Country Resource

United States 4

Argentina 2.6

Afghanistan ?

Australia 0.63

Bolivia 9

Brazil 1

Canada 0.36

Chile 7.5

China 5.4

Congo 1.0

Portugal 0.01

Serbia 1.0

Zimbabwe 0.023

WORLD LAND TOTAL 33

WORLD OCEANS 240

Source: U.S. Geological Survey (2011).

more than the 800 million vehicles that exist today.
As such, lithium may not be a limiting factor in electric
vehicle production in a 100 percent WWS economy. If it
is, additional potential sources of lithium are the oceans,
which contain 240 million tonnes, far more than all
estimated land resources. However, currently, the cost
of extracting ocean lithium is high and energy intensive.
Finally, if demand does grow to the size of supply, the
price of lithium will rise, spurring the hunt for new
sources of lithium and encouraging more recycling.

13.7. Downtime of Wind, Water,
and Sunlight versus Conventional
Energy Technologies
One goal of any electric power system is to mini-
mize downtime due to system failure or maintenance.
Extreme events and unplanned maintenance can shut
down plants unexpectedly. For example, unplanned
maintenance can shut down a coal plant, extreme heat
waves can cause cooling water to warm sufficiently to
shut down a nuclear plant, supply disruptions can curtail
the availability of natural gas, and droughts can reduce
the availability of hydroelectricity.
WWS technologies generally suffer less downtime
than do conventional electric power technologies. For
example, the average coal plant in the United States
from 2000 to 2004 was down 6.5 percent of the year for
unscheduled maintenance and 6.0 percent of the year for

Figure 13.15. Road through Salar de Uyuni,
southwest Bolivia, the largest salt flat in the world.
The crust, consisting of halite and gypsum, covers a
brine pool containing the largest lithium resource in
the world. C Paop/Dreamstime.com.