As surprising as it might sound, there are actually dozens of working prototypes for vehicles that can run on water. Of course, you don’t see any of these being picked up by the car manufacturers around the world.
One of the most documented (and famous) of these cars was a buggy created by Stan Meyer. This impressive invention achieved an average of 43 kilometers per liter (100 mpg) of water. Colleagues close to Meyer say that he was under a great deal of duress to sell the patent to his creation and end his research into water cars.
But he refused to be bullied into giving up on a working invention that could completely change the world. Although the same colleagues and friends shouted from the rooftops that Meyer was poisoned for his refusal to submit to big oil companies, it is documented that Meyer died without warning from a brain aneurysm.
Free Energy (Nikola Tesla)
Nikola Tesla was perhaps one of the most well-known inventors in the world. Although everything created by his mind might not be life-altering, free electricity for the entire world should certainly perk up your ears. After successfully (and in well-documented cases) demonstrating that he could wirelessly transfer electricity, Tesla made it known that he was developing prototypes that would amplify this phenomenon and power large areas from a single tower.
Though most at the time believed this to be a real possibility, Tesla’s funding for the project dwindled to nothing and his laboratory with the prototype parts and plans mysteriously burned to the ground. This is perhaps the most documented of all the suppressed and stifled inventions that you will never see, and it is among the most globally significant.