A recent blog piece indicates worldwide production of tellurium amounts to about 135 metric tons and that this entire amount would be required to produce a single GW of electricity using current CdTe photovoltaic cells.  They indicate the three main uses for tellurium today are hardening steel, thermoelectric coolers and now CdTe solar cells.  Their point is, of course, is there may not be enough tellurium to do everything we want to do with it.