They answer to governments.
I strongly disagree with you here renton. I think it's the other way round. Governments answer to the central banks. That's why we're all in so much debt. The only nations that do not answer to the central banks are the ones we invade. And Iceland, who were on our terrosit list for a short time but I guess we realised that there would be literally no justification to invading Iceland.

Oil is incredibly abundant and cheap compared with the alternatives, that is why it is the prevalent source.
This is just wow. Why don't you try comparing UK or US energy prices with, say, Iceland? Iceland's energy comes almost exclusively from hydroelectic and geothermal, with 0.1% fossil fuels. We pay twice as much for energy, I'm not sure about you guys because the stats I found include gas for cars, which you're gonna get a lot cheaper than Iceland, plus it probablt varies across states. The vast majority of nations that are cheapr than Iceland are big gas and oil exporters.

Geothermal is much cheaper. Infrastructure would obviously be very expensive, but we're talking of a super high speed train between London and Birmingham and up North, because saving half an hour getting From London to Manchester is worth many billions of pounds apparently. We can afford to consider trains that go 150mph+ in a small nation, but we can't have clean renewable energy?

What are the maintenence costs of geothermal? Negligable when compared to drilling oil from the seabed.

Oil is not abundant, far from it. It is not renewable, we are using a lot more oil than the earth can create. Thus, it is scarce. Abundant means we are using less than can be made, at least when it comes to energy.

The prices of abundant resources quickly approach zero in a free market
You say this, but this supports my argument! Why would the powers that be want us to be using an abundant energy source that is virtually free? This is why we're still drilling oil! Because it's scarce, not abundant, and as such can be sold at a much higher price than alternatives.