I can't recall seeing this discussed here before and a search failed to turn up any hits so..
It seems that in addition to Fusion and Fission it might be possible to extract enregy from "Low Energy Nuclear Reactions"...
20+ years ago the cold fusion scandal came and went. However it never actually died. Some people continued to experiment but nobody was able to reliably demonstrate working cold fusion. Nevertheless some people got strange results that suggested energy was being produced even if it wasn't fusion. Two reviews conducted by the Department of Defense in the USA were unable to determin if this was a real effect or not.
Then in 2005, Dr. Allan Widom and Lewis Larsen began publishing papers that presented a new theory to explain these experimental anomalies. These papers were published in respectable journals so they have a certain credibility. The Widon-Larsen theory claims the anomalies discovered by cold fusion researchers are NOT due to fusion reactions, which would involve the strong force, but to other low energy nuclear reactions that involve weak interactions (hence Low Energy Nuclear Reactions or LENR).
Then in January this year Italians Sergio Focardi and Andrea Rossi announced and demonstrated what they claim is an "Energy Catalyzer". They claim this uses hydrogen and a secret catalyst to transmute Nickel into Copper while liberating energy. They claim that energy is produced at a level that can't be explained by a chemical reaction. They don't call it "cold Fusion" (although many web sites have) and I suspect they can't call it "LENR" either due to the Larsen patent. They have applied for their own US patent and have been granted an Italian Patent.
Is it a scam? Who knows. It does have some of the hallmarks. It's unfortunate that they feel unable to release enough information into the public domain for others to validate. However if it works as claimed it represents a significant development in renewable energy generation.
NASA's chief scientist Dennis Bushnell comments on LENR about 5 mins into this interview..
http://www.evworld.com/evworld_audio/dennis_bushnell_part1.mp3 He lists LENR as
"the most interesting and promising" development in renewable energy.
