Cold fusion, commonly referred to as a “Low Energy Nuclear Reaction” (LENR), is a hypothesized process in which the fusion of atoms occurs at temperatures that are close to room temperature as opposed to those reactions that occur regularly in celestial bodies such as stars that operate at extremely high temperatures. This reaction has been highly sought after for many reasons as the ability to produce energy from the fusion of atoms with a minimal energy input to maximize the potential energy output could provide a reliable, powerful source of renewable energy for use throughout the world.
This process is described as “hypothesized” due to the fact that, despite scientists initially claiming success in 1989 in producing what could be described as “cold fusion” energy in a controlled electrolyte solution, no further experiments could be conducted on the process to confirm it, duplication of the described process produced no energy byproduct, and many of the other claims made by the initial experimenting scientists were later disproved. These two scientists involved in the experiment were Martin Fleischmann and Stanley Pons, and their disproved theory has been dubbed the “Fleischmann-Pons claims”.
Despite this setback many scientists have continued to research into the concept of fusion energy and have developed another form of fusion that does not require the massive amounts of heat as used in thermal-nuclear fusion (common to stars such as the Sun). Unfortunately this process is on the opposite end of the spectrum and requires temperatures far below standard room temperature to operate and is known as “muon-catalyzed fusion” where minuscule energy particle reactions at significantly low temperatures that facilitate energy flow to produce power. While in some ways this is referred to as cold fusion due to its low operating temperatures at the same time it does not satisfy the basic concept of cold fusion in which the fusion process can be conducted with minimal energy input at room temperatures as maintaining a constant low temperature requires additional energy output that detracts from the overall benefits of the reaction.
Regardless of all of the interest and focus placed upon the process, however, cold fusion still remains an unattainable goal given the limitations of being able to produce a controlled reaction at a large enough scale to make energy production practical, even while using a muon-catalyzed fusion process. Because of these limitations many researchers are actively considering utilizing a hybrid fusion/fission process as current attempts at cold fusion even in small quantities are generating large amounts of fissionable material in the process such as thorium-232 that could be used to produce uranium-233, however this process is still under consideration as it would require extensive processing that may make any net energy gain negligible.
Many experts anticipate that cold fusion in some form will be realized in the not too distant future, however further advances in technology and energy processing techniques are required first before this can be realizable at any practical level, though depending on the rate of technological process this may take place in the coming decades.
http://www.eco20-20.com/Solar-Energy-Storage-Pros-and-Cons.html