If these alternative energy sources are better than Fossil Fuel corporations, one would think that they'd outcompete them in a capitalistic economy.
The main problem is refuiling stations. There are already thousands of gas stations, but not one supplies any other forms. Also, the auto market produces primarily vehicles that run on gasoline. I have not extensively looked into the subject, so I do not know whether or not it would be more efficient that gasoline, but they are more than good enough to run on effectively now. Also, gas will only become more and more expensive, so eventually, it will be cost-effective to switch.