As Chris Ransford said, the simple answer is: No, it won't work. In order to fuse two nuclei you have to overcome the Coulomb-barrier which is done by quantuum mechanical tunneling.

The tunneling probability goes with temperature and height of the potential well. If you calculate the tunnel probality of two protons (as simple estimation) at room temperature you will end up with a probability of ~10^(-80) which is means that only one out of 10^80 protons will fuse with another but to my knowlegde this is the estimated number of protons in the whole universe...

No.

They're business scams designed to find investors.

I have seen so many of those - the scams are predicated on the fact that most moneymen, VCs and others, are scientifically unwitting (they typically know all about finance and gelt and nothing about physics) and on the fact that it's one of the few ways to pull off a perfectly 'legal' scam - as in, it is not unlawful to make a mistake in math or physics, and investment monies are simply forfeited when the prototype or scheme turns out to not work.

I had analysed in depth the cold fusion claims in a Business Plan submitted to some investors who had asked me to vet it. Do that: cold fusion does not make sense - the energetic balance is unworkable to begin with, owing to the energy required to break through the electron barriers, etc. etc .

I am not really interested in reading the paper you quote, so I cannot specifically comment on this particular paper, but I have seen papers posted here and there and more such démarches, all meant to bolster claims to apparent respectability.

The US Department of Defense has been approached so many times, has looked into it and has reached the same conclusion. Nevertheless, many such scammers state that they are Quote in talks with the Department of Defense Unquote. When pressed further, they hide between the DoD's policy to never confirm or deny contacts .... It's all pretty sad.

As Chris Ransford said, the simple answer is: No, it won't work. In order to fuse two nuclei you have to overcome the Coulomb-barrier which is done by quantuum mechanical tunneling.

The tunneling probability goes with temperature and height of the potential well. If you calculate the tunnel probality of two protons (as simple estimation) at room temperature you will end up with a probability of ~10^(-80) which is means that only one out of 10^80 protons will fuse with another but to my knowlegde this is the estimated number of protons in the whole universe...

So it is not possible from first principles, except some new physics is hidden behind.

But such an extraordinary claim calls for very high quality, convincing proofs and it seems not to be the case.(some mechanism enhancing tunneling probability), for example). Then it is a case study of the sociology of science, which sometimes tries tio be "fast science". It can make only damage to the public view of the science as a whole. I think it should enforce efforts othe science community to promote good, "slow" science.

In this field there is a lot of junk around. I would say the 99.9%. I know the work of levi et al. My opinion is that they are not convincing since there is nothing indicating that some "fusion" is occurring and basic infos are missing for an indipendent replication (assuming not a fraud)

On the other hand, there are models that use just standard model physics and plasma physics to predict some observable effects for low temperature nuclear reactions. There's not anything in the theoretical work of Srivastava, Widom et al. that seems to be wrong. They predict production of thermal neutrons and gamma flux from hydrurated nickel (or any material that can be hydrurated) if "high" elm energy density is there. If they are there, they should be seen, if the model is correct. This can be tested experimentally (and we are setting it up to test if this is true).