we could have abandoned fossil fuel a long time ago. The US Airforce were involved and the patent was canceled due to non payment?
Well evidently zero point energy may be something according to this Wikipedia article. Just because a patent is issued does not ensure it is practical or even that the technology works. The patent issued in 1996 so society was aware of it for more than 20 years. My guess is that people worked on this and found that it didn't work well enough to be practical. A patent may be cancelled if required payments aren't made. This often happens when someone owns a patent that isn't worth the value of the payment. When this happens, the patent becomes available to anyone in the public to use without license earlier than when it would otherwise expire.
I can't see where there is the possibility of conspiracy here. If you believe this is the next great thing, then go ahead and develop it. It is fully available to you.