Hm... new inventions which vastly improve current technology... new inventions which replace current technology with better counterparts...untold wealth being witheld from the general public by greedy corporations...
Anybody else think this sounds like the Gold Rush?
It pisses me off when I see people who think that somewhere, there's a free lunch.  Or, at least, a lower cost, better tasting one.
Inventions don't "disappear" if they're so revolutionary oil companies would buy it up and bury it.  Applying for a patent requires revealing how the invention works, which means it's kept on record at the patent office.  Take a guess as to how patent violations are verified.  Last I checked, patents tend to expire rather quickly... something like 20 years at the most, I think.  In any case, at some time, the patent will expire, which means it's up for grabs.  If patents were eternal, who would get the payout?  The inventor's direct descendents?  No, even if patents last the life of the inventor, they will expire at the time of death.  Otherwise, we'd have some seriously rich families, and at a certain point in the future, everybody would be related to each other, making the patent moot.
So, in the end, conspiracy theory or no, revolutionary inventions which work always survive.
As for alternative fuels, well, that's another myth.  It's true electricity is environmentally friendly.  It runs without byproducts (unless you count oxidation).  However, getting the electricity is not friendly at all.  The cleanest means is solar, which at this point is very inefficient.  True, large advances have been made, but last I heard, highest efficiency was around 30% or so... for an almost purely thereotical construct.  Besides, you'd have to make sure the panels are unobstructed, which means either space (too expensive to send up and maintain) or vast swathes of land with 100% restricted airspace.  Gee, where's my bunny gonna live if his burrow is gonna be covered with a solar panel?
After solar, every other means involves large environmental impacts.   Dams destroy large ecosystems upriver by building a lake and everything down to the sea.  Windmills extract energy from the air movement, which will affect surface temperatures and storm formation.  Burning fuel for electrical powered cars increases polution because you've just added one more energy conversion, which reduces efficiency no matter how you look at it.  Fuel cells run into the same problem, seeing as one has to create the fuel in the first place.
So, in the end, there is no holy grail.  Somewhere, somehow, you're extracting energy from somewhere, and ruining somebody's backyard.  When horses dominated the U.S. landscape, they were dirty, smelly, and left the streets in bad shape.  Gas powered cars burned clean, efficient, and required less maintainence.  That was before the whole spat over ozone depletion and the rise of smog covered cities. 
Edit: One more thing.
Wanton destruction of innovation is really bad for business.  It's true that pure business means maximizing profits and longevity, but if something comes along that's better and cheaper, it gets done.  One doesn't sit on technology that would increase profit margins with the same market size.  Same goes for technology that thins margins but increases market (think of how shipping and driving habits would change if gas was hella cheaper).
If you want a well known example, you need only look at Intel.  Innovation through a recession.  Intel engineers don't sit on their asses all day just because the current product is profitable, and they're not afraid to scrap everything and start from scratch (Itanium).