LENR stands for Low Energy Nuclear Reactions, (or sometimes Lattice Enabled Nanoscale Reactions) and refers to the phenomenon where anomalous amounts of heat are created when certain metals (e.g. nickel, palladium) absorb hydrogen or deuterium and an external stimulus such as heat or an electric current is applied. The reaction takes place at relatively low temperature and sometimes results in transmutation of elements as well as the production of heat. Either no strong radiation is produced or it is absorbed locally. The waste products have been found not to be radioactive. This phenomenon is also referred to as Cold Fusion, LANR (lattice assisted nuclear reaction), as well as other terms.
Modern interest in LENR began in 1989 when scientists Martin Fleischmann and Stanley Pons announced at the University of Utah they had succeeded in generating nuclear reactions in laboratory experiments. This announcement sparked much interest in the media and in the scientific community, with many researchers attempting replicate the effect in their own experiments — many without success. The effect was not always easy to replicate, particularly as the preparation of the metal was critical and it sometimes took weeks for anomalous heat to appear. The inability for many researchers to replicate Pons and Fleischmann’s experimental setup led to a backlash against the two from scientists from well-known scientific institutions, and Pons and Fleischmann were effectively treated as pariahs, and they were largely considered either incompetent or fraudsters.
While much of the mainstream scientific community dismissed LENR/Cold Fusion as pseudoscience, a small core of researchers continued work in the field, and interest has increased significantly since 2011 when Andrea Rossi and Sergio Focardi first announced their results working with the Energy Catalyzer (E-Cat). Since this announcement, there have been attempts by various parties to be able to replicate and control the LENR effect. Rossi’s E-Cat has received a lot of attention because he was the first to publicly demonstrate his device and it has now been been tested by third parties, demonstrating at least ten times the energy of any known chemical reaction and showing that the E-Cat is capable of producing useful heat.
Various claims by Rossi and third party testers are for the E-Cat producing a Coefficient of Performance (COP) from 6 to over 50 (meaning between 6 and 50 times more energy is produced than is input into a system). Even at the low end such a device could make obsolete virtually all other ways of producing power.
The high power- and energy density of LENR seems to compare with a nuclear process, and Andrea Rossi is now testing a 1 MW plant which is intended to last for a year without refuelling. If LENR is proved that it works, the cost of energy would likely dramatically drop. LENR has the potential to be the energy source for humanity for the next centuries and may be able to stop the exhaust of CO2 in the atmosphere.
In addition to Rossi, there are other attempts to build systems that can produce energy on a commercial scale. Some other companies and individuals involved in this effort are Brillouin Energy, Inc., Clean Planet, Inc, Jet Energy, Inc., Nichenergy SRL and Etiam, Inc.
High temperature, more efficient designs would be suitable for powering transport, even aircraft, although this would probably take decades. This promise of inexpensive, safe, clean power is why many are now following the subject.
As to exactly what is physically happening in LENR reactions, there are many competing theories about what causes the effect, but none so far has been widely accepted or definitively proven.
Lenr-canr.org — A library of research papers on LENR
LENR Proof — Examination of the commercial viablity of LENR
LENR For the Win — An examination of the evidence for LENR
Martin Fleischmann Memorial Project — An open science project to provide convincing proof of the ‘New Fire’
Vortex-L — Archive of email list dealing with LENR-related topics