Because it is not a natural source and one day it will end up being none left. Oil takes millions of years to produce that oil from underground and it is said that we use it much faster than it produces.
Oil
oil
Oil has a reserve of chemical energy. If we burn it, that gets converted to heat energy.
The sun
Oil
Oil
Oil is a non replenishable source of energy. and, Oil is a "fossil fuel".
The Sun is the ultimate source of all energy on earth.
tecnology and oil
oil that is imported
Oil
Oil, for now....