Question

for fusion to happen the process needs to overcome the Coulomb Barrier. how does fusion work for cold fusion?

Answer 1

Theoretically, cold fusion works by fusing atoms that are at room temperature. The initial theory was that if palladium could be fused with hydrogen at room temperature electricity would be produced.
This electricity would be created with no waste or radioactive byproducts that could harm the environment. However, the cold fusion process must be stable to be usable and to date it has been impossible to put the theory into practical application.
The experiment to produce energy using cold fusion appears to be rather simple. There are three ingredients involved. Palladium is a metal similar to Platinum. The hydrogen used is deuterium found in waters of the oceans.

A demonstration of the process places palladium in water that contains deuterium. The third ingredient is electrical current. Researchers contain the experiment by wrapping the container in insulation while instruments measure the reaction.

The goal is to create more heat (power) coming out of the experiment than the current creates as it enters the water. If excess heat is measured, energy is being produced by cold fusion. No one seems to know exactly what process is involved in producing energy through this experiment.

The most likely explanation is that energy is being created through a nuclear reaction that occurs at a slow pace. The slower reaction rate may be the reason radiation is not a by-product of cold fusion.