Name Peat
Source Mod Forestry
ID Name Unknown
Type Fuel
Stackable Yes (64)

Peat is a solid fuel produced by leaving Bog Earth to mature within 2 blocks horizontally of water (including diagonals). 1 square of water will slowly mature Bog Earth blocks into Peat blocks in a 5x5 square around it. Note even the shallow end of an 8-long trench of flowing water supports Peat development to a distance of 2 blocks. A given block containing Water will not mature Bog Earth blocks on a level above or below it, however a Bog Earth tube with water flowing down through the center will mature since each layer is adjacent to water horizontally. When manually farming Bog Earth into Peat, while tools with Efficiency enchantment seem faster, no particular tool appears to have any given advantage in breaking matured Peat blocks. Once broken, they give a 1 Dirt and 1 Peat as items. Placed blocks of Bog Earth are light brown, while matured Peat blocks are dark brown (See image below).

Image shows the maturation of Bog Earth into Peat blocks within 2 blocks of water, even moving water.

A peat farm can also be built and maintained automatically by a Peat Bog, while a Turbary takes care of harvesting. Peat is used as solid fuel in peat-fired engines, providing 1 MJ/t for 5000 ticks. It's combustion in such an engine produces Ash at a rate of one per 1.5 peat, which can then be used to craft Fertilizer (Forestry), Compost, or Bituminous Peat.

Peat will burn very slowly. A single peat bog should produce enough fuel to keep as many as 10 Peat-fired Engine running.

Peat can also be used as a substitute for Coal or Charcoal in furnaces and it will smelt more items. Despite peat being a lesser engine fuel than bituminous peat the latter can't be used as furnace fuel. Also no ash is produced when using peat as a fuel source for vanilla furnaces.

The following table shows the increase in efficiency of vanilla furnaces of 1 peat used instead of charcoal or coal:

Furnace Type Items Smelted Efficiency Gain
Furnace 10 25%
Iron Furnace 12 20%

If you have IC2 installed you can also put Peat into a Generator to give you 4000 EUs or 256,000 EU for a whole stack of peat.