<mix...@bigpond.com> wrote:
> Why would we want a technology based upon scarce (& expensive) substances > (Pd & > D) when we can have one based on cheap and readily available ones (Ni & H)? > For the next several years I think researchers should concentrate on Ni-H, but I think it would be a good idea to revisit other systems such as Pd-D and even Au-H. Reasons: We need broad understanding of the physics. These others might have lessons that are not as easily learned from Ni-H. I don't know that for a fact, but it is possible. There may be some niche applications or operating domains in which these other systems are superior. For example, one of them might work at low temperatures, so it might be better for small implanted medical devices with thermoelectric chips. It is hard to imagine implanting a micro-mini-Rossi device, which only operates at ~600°C (I think). Even though the materials are more expensive, in some applications this will not matter. Suppose it turns out you can extract much more energy per gram from a Pd-D system than Ni-H. Again, that would make it attractive for implanted medical devices, and also for satellite power supplies or remote, unmanned telephone repeaters, UAVs that stay aloft for months, and various other applications in which people spare no expense. Think of today's energy systems. There are cheap, large scale ones such as gas turbines. At the other extreme there are tiny ones such as hearing-aid batteries. The cost per watt of capacity for a hearing aid battery is probably astronomical, and the materials are probably rare and expensive. But the technology is useful and profitable. - Jed
