[ethan_smith]

Head End Power (HEP) is the electrical power supplied from the locomotive to the passenger cars for lighting, heating, air conditioning and other amenities - essentially the "hotel load" that keeps your private car functioning while attached to the train.

[Llamamoe]

Why is it so much? I can't imagine a few lighting and heating fixtures using several thousands worth of electricity.

[Ambroos]

Power generated on a train is probably significantly more expensive than power you can pull from the grid. Most of Amtrak's network does not have power so I assume they rely on generators on the train.

[IsTom]

OTOH if you want a bunch refrigerator cars it might take a bit more power.