Use a [[shovel]] to dig peat from a [[peat tile]]. At the moment, the only known use is to burn it in [[Campfire|fires]], [[Stone Oven|ovens]], or [[Forge|forges]] to be used as a fuel.
When used as a [[fuel]], peat is four times as effective as wood. Tar is 8x more effective, Therefore, burning a 10kg piece of peat is equivalent to burning 40kg of wood, putting any of the above fire sources to their maximum burn time.
[[Peat tile]]s can be raised by dropping [[dirt]] or [[sand]]. They can be lowered with the [[level]] command if all corners are higher or level to an adjacent flat tile and your [[digging]] skill is at least 70.