Steam Engine

The steam engine is an early game (and pre-polymer) method of turning steam into energy similar to the steam turbine.
Usage

The steam engine requires two external sources to provide steam and reprocess the low-pressure steam produced respectively. Using a boiler connected to a heat generating machine (or solar boiler) with water inputs will produce the steam required and connecting the steam engine to a steam condenser connected to the water loop will allow you to cycle the water indefinitely. The described process would look something like what is pictured in the example image on the right.
Crafting
Crafted in a Tier 2 Anvil:

