John's right.
Any energy extracted from beneath the ground is also a diminishing resource.
But with the massive increase in consumption, especially from high growth countries like China and India, we are finding even greater demands on those diminishing resources.
We have to accept that for the rest of our lifetimes, energy costs are going to go through the roof. It's the supply and demand thing illustrated by John.
Bio fuels have a role to play in easing the situation, but that is already creating new problems with food production. It appears that locally, rape acreage has gone through the roof, and I bet much of this is to do with bio fuel rather than food.
Now to be controversial. In the changing world, the only energy that looks capable of being a winner is nuclear
All that mankind needs to do is solve the problem of waste. Perhaps we should take up the Australian offer of dumping it in the central Australian wilderness. After all, nobody lives there :
Perhaps I should stick to my clean-in-use electric porty for now :
Safe and happy cleaning
Ken