Indeed. Something of this nature would have such a profound impact on the world in general, and world economies in particular; that that would be the only way to get it out to the public. Publishing for all the world to see, full detailed plans on how to build, operate and maintain such a device. Otherwise governments, companies, or someone else is gonna come along and kill it, and most likely you (a bullet is cheaper than lots of cold hard cash) along with it.
Still, work continues on so-called free energy. I was surprised to learn that a patent has been issued on a device for collecting energy from a vaccum. You can read about it at Understanding Zero Point Energy