Matter is bound up energy, and energy is liberated matter. ― John Worrell Keely 1893
Another great video from The Why Files, 5:06 to skip the intro stuff. Dr. Steven Greer is featured in this towards the end, his newest documentary covers this topic as well, called The Lost Century and How To Reclaim it, here's a trailer.
The Why Files video mentions a few of these cases of suppression. In Greer's Document Library there's a 137-page document titled: "Energy Invention Suppression Cases" by a Gary Vesperman.
Here's an excerpt from the final section in the document titled 'How to Stop Energy Invention Suppression':
Even if HALF of these suppression cases can somehow be found to be false, the conclusion is still inescapable that we have a very, very serious problem of which very, very few people are even aware. Hundreds of billions of dollars of energy business are at stake. I can not think of another issue that is more fundamental to American politics than energy invention suppression.