The total Cd use in the United States in 1997 was 2600 tons; globally, it is
approximately 20,000 tons per year. Cadmium is employed primarily (~65%) in
nickel–cadmium rechargeable batteries, paint pigments (~17%), plastic stabilizers
(~10%), for metal plating (~5%), and metal solders (~2%). Using only 1.5–3% of
the nation’s consumption of cadmium in manufacturing CdTe solar cells (i.e. 40–80
ton/year) would generate over 1 GW of new PV per year. I note that the total current
PV capacity in the United States is only 0.3 GW and is projected to grow
(under optimistic assumptions) to about 3.2 GW/year by 2020. Even envisioning
an order-of-magnitude higher PV production (e.g. 32 GW/year) would require
only about a sixth to a third of the current US Cd consumption. New solar energy
at such very large scales would significantly change the mix of electricity sources in
the US and abroad, preventing carbon dioxide and other emissions.
It is interesting to compare Cd flows in CdTe PV with those in Ni–Cd batteries
and coal-burning power plants.