I wouldn't argue with +tess caline
's point that oil is a limited quantity, regardless of whether we've hit "peak oil" or not, and that conservation is worth consideration.
Know what lowers the price of energy (assuming no unlawful collaboration)? High energy prices. I heard something about this on the radio a while back, and the terrible part is that I can't recall the era, but I'm fairly sure it was prior to 1930. Gas prices were in the neighborhood of a dime, there was a crunch, and a subset of politicians advocated government control of supply and demand, citing fears that gas prices would soon hit a dollar a gallon. Prices did increase, creating incentive for innovators to improve refining processes and alternatives. While prices didn't fall to the original levels, the market corrected. A truly free market is an important part of that, and a part I don't know whether we can reach again or not. But, I'd like to think it's possible.
On a side note, if you index history to the price of gold, nothing is really out of line price wise. Our dollar is just worth one tenth of a tin shit right now. And the discussion of why that is the case is too long to get into, and something I haven't even spent sufficient time to fully understand, but the short story is: Fiat currency sucks.