This web page goes a long ways to explain how it is theoretically possible to harness free energy and why it is not part of our current power system.
https://peswiki.com/index.php/Site:LRP:The_Deliberate_Curtailment_of_Nikola_Tesla's_Primary_Energy_Source
"…[There is] .. an often-overlooked feature inherent in the law that energy can neither be created nor destroyed. Rigorously, work is defined as changing the form of energy. When one joule of energy performs one joule of work, one joule of energy still remains, but in an altered form. If that remaining joule of energy has its form changed yet again, another joule of work has been done. And so on." [M. W. Evans, P. K. Anastasovski, T. E. Bearden et al., "Classical Electrodynamics without the Lorentz Condition: Extracting Energy from the Vacuum," Physica Scripta, Vol. 61, 2000, p. 515-516].
Dan
https://peswiki.com/index.php/Site:LRP:The_Deliberate_Curtailment_of_Nikola_Tesla's_Primary_Energy_Source
"…[There is] .. an often-overlooked feature inherent in the law that energy can neither be created nor destroyed. Rigorously, work is defined as changing the form of energy. When one joule of energy performs one joule of work, one joule of energy still remains, but in an altered form. If that remaining joule of energy has its form changed yet again, another joule of work has been done. And so on." [M. W. Evans, P. K. Anastasovski, T. E. Bearden et al., "Classical Electrodynamics without the Lorentz Condition: Extracting Energy from the Vacuum," Physica Scripta, Vol. 61, 2000, p. 515-516].
Dan