Many believe that free energy, overunity or any number of terms applied to devices that produce more energy than they consume to be an impossibility. However many also believe in made up sky gods, the sanctity of the market or that consumption will heal the environment. The only thing that will truly prove if such technologies are possible, are experimentation. unfortunately for free energy, if it were proven to be possible it would destroy the market system. The market cannot allow such technologies to exist as they cannot be centralized once put into production. Free energy would allow for production outside of the market.

there may be:
a catalyst - a catalyst causes a reaction to take a lower energy pathway than it normally would without being used in the process.
CETI Patterson Power Cell

sound/vibration/radiation - some forms of radiation affect molecules. sounds frequencies?

Stanley Meyer’s water fuel cell

In 2006 Steorn announced a call for scientists to validate their claims of free energy using a magnetic system.