Editing Snowpiercer (section)

===The Eternal Engine===
Snowpiercer is powered by a perpetual-motion engine designed by Chief-Engineer Melanie Cavill and referred to as the ''The Eternal Engine'', running on hydrogen gained from snow outside. Engineer Bennett Knox noted that, while the fuel is eternal, parts of the Engine are not and will eventually break and need replacement.  It appears to produce more power when traveling at greater speeds. A display in the Engine Car features kWh/km units. As the train slows, the energy produced decreases, as does the distance traveled per second, providing a "double whammy" effect of reducing power.

At the train's average speed of about 100 km/hour, each "unit" of power production gives 100 kW, and from an estimated typical power generation of 20 kWh/km, the train's total power production is normally 2 MW, enough for roughly 2,000 modern American homes. It seems to be enough to keep the train life support and communication systems working, load the Battery Cars, and make the First Class extra-amenities (sauna...) work.