A couple of years ago there was a stir when it was claimed that the isotopes known as nuclear isomers could be triggered to release their energy by a process simular to lasing. The last I’d heard about it though it seemed to fall into the category of “lone wolf makes dramtic claim, results not replicated”. So was this a flash in the pan like cold fusion, or is the jury still out?
It’s nothing at all like cold fusion, since you still need to put the energy there in the first place. They might someday end up being used for super-high-energy “batteries”, but they can’t be used as a primary power source (aside from tantalum-180m, but that’s very rare).
I think it’s theoretically possible that isomer energy could be “triggered” but there’s no convincing evidence that this triggering has ever been done successfully - this puts it one up on “cold fusion” which was pretty dubious from the theoretical point of view and was weakly supported by the evidence as well. “Imaginary Weapons” is a pretty good book on the topic, but it suffers from the problem that the author is not all that familiar with science (judging by the mistakes I saw in the book).
You could stimulate long half-life isomers to decay via neutron absorption or some other input that perturbs the nucleus; however, I doubt this will ever be a very effective method of either storing or producing energy on demand, at least given any extension of known technologies.
Chemical isomers hold quite a bit of interest as high capacity power producers for high energy lasers and as a high specific impulse chemical propellant, but the very short half-life of such structures makes their utility extremely limited.
Stranger