Palladium is expensive and rare. If it turns out we can only generate cold
fusion energy from palladium, and not some other metal such as nickel or
titanium, this will probably limit the use of cold fusion to things like
central generators which have a high duty cycle, making maximum use of the
metal. However, palladium is not so rare that a Pd-D energy source would
make only minimal contributions to overall energy production. It could
generate more than coal, or natural gas, or any other single source today.
Martin Fleischmann once estimated that it could produce about one-third to
half of all electricity. I believe that is reasonable.
In other words, Ni or Ti would make cold fusion cheap and ubiquitous, but
even with Pd we could supply a large fraction of today's energy, and it
would be cheaper than any other energy source.
Here are three very rough estimates, with different assumptions.
The palladium supply in 2015 was 6.7 million ounces mined, 2.6 million from
"secondary recovery" (recycling). That is 190 million grams mined, 74
No increase in production despite increased demand. Production from mines
continues to be ~190 million grams per year, indefinitely. I think this is
unrealistic. When demand increases, more mines are opened and extraction
The main use of Pd today is in catalytic converters. Assume that
eventually, all cars are electric and no more use of Pd is needed for
catalytic converters; nearly all Pd used for cold fusion.
No transmutation of Pd. The Pd is in sealed cells, so little is lost. 95%
is recycled; 5% lost.
This means that after 20 years, annual losses would equal production and
the supply would not increase. The total supply would then be 3.8 billion
grams. (I ignore today's existing stocks.)
Additional assumptions regarding energy production
With Pd-D 200 W/g can be achieved, at any desired temperature up to the
melting point of Pd. I believe the current record is 25 W/g, which is
approximately the same power density as a uranium oxide fuel pellet in a
conventional reactor. See "Power density is compared by volume or by
(Note that Pd weights 14 g/cm^3.)
I think higher power density might be possible with nanoparticle Pd.
The Pd would mainly be used for applications with a high duty cycle, such
as centralized electric power generation, railroad locomotives, and
pacemakers. (Pacemakers have very low power but they must maintain a 100%
duty cycle or the patient may die.) Assume the Pd is active 60% of the time.
With 3.8 billion g, that comes to 0.456 TW thermal output. Electricity
requires 5 TW thermal to produce 2.3 TW electricity. Assume thermal
conversion efficiency does not improve. In this case, 0.456 TW would
produce 9% of electricity.
Cold fusion would make Pd quite valuable, so let us assume production
doubles to 380 million grams.
Lead-acid batteries resemble cold fusion cells in that they are sealed and
none of the metal is used up or lost. Nearly 100% of the lead is recycled.
Assume that only 1% of Pd is lost every year, because most Pd generators
are large, central units that are carefully recycled. After 100 years we
would have 37.6 billion grams.
Assume no increase in the thermal efficiency of conversion, and the same
200 W/g and 60% duty cycle.
Total thermal output is then 4.5 TW which produces 90% of today’s
electricity. However, there is no doubt demand will grow, so perhaps it
would be about half of total electricity.
HIGHLY OPTIMISTIC ESTIMATE
Assume Pd can be extracted from seawater, or from mining asteroids.
Asteroids are 80% iron and “20% a mixture of nickel, iridium, palladium,
platinum, gold, magnesium and other precious metals such as osmium,
ruthenium and rhodium.”
“The platinum group metals are some of the most rare and useful elements on
Earth. According to Planetary Resources, a company that hopes to mine
asteroids in space, those metals exist in such high concentrations on
asteroids that a single 500-meter platinum-rich asteroid can contain more
platinum group metals than have ever been mined on Earth throughout human
This would give us enough Pd to produce all of the energy on earth and in
the solar system.