There has been much ado about almost nothing following the 1989 announcement by Fleischmann and Pons that they had produced energy in a flask of heavy water. The experiment consisted of electrolyzing the D2O into gaseous products by apply­ing a DC voltage between an anode and a cathode, the latter made of palladium. The energy input and output from the apparatus had to be carefully measured.

There was energy balance for several weeks, but then they found that the output was a few watts larger. Since then, the experiment has been repeated hundreds of times by reputed scientists without similar success. There have also been many believers in cold fusion who accuse the scientific community of snobbish exclusiv­ity, and who occasionally report observations of excess energy generation. The American Physical Society has held conference sessions and panel discussions on cold fusion with the conclusion that it is impossible.

Electrochemical potentials are sometimes surprisingly strong. The hydrogen car fuel cell (Fig. 3.51), for instance, uses a platinum or palladium catalyst to dissociate and ionize hydrogen magically before it has been heated. There is, how­ever, a huge difference between the 10 eV in ionization and the 10 keV in overcoming the Coulomb barrier in fusion. In cold fusion perhaps the deuterium seeps into the palladium after some time, and eventually two D’s get very close together and somehow the applied voltage can cause them to fuse. Sometimes a few neutrons are observed, but these could be due to cosmic rays. There is interest­ing physics in these infrequent events, and the International Conference on Cold Fusion has been meeting annually since 1990. Institutes for cold fusion have been established in some countries. However, cold fusion power is so miniscule that it would not pay for the palladium, much less a whole power plant. And it is only thermal power, not direct electrical power. Cold fusion may have interesting sci­entific aspects, but it has no relation to power production.

The uproar over cold fusion has had one benefit, however. It shows that the public is not disinterested in controlled fusion power, as long as it is cheap. It sim­ply does not understand why it is so hard to achieve, and why there are no shortcuts leading to the gold at the end of the rainbow. This book attempts to explain why.