Really efficient. They use less than 1/3 the energy of a freight train, per tonne per kilometre*, and in some places (like BC) the power mix is vastly greener for the pipeline than the train.
First, excellent story of the day, a Belgian brewery wants to put in a beer pipeline. This is awesome.
Second, my good friend Michael made a quip about this, saying "not all pipelines add greenhouse gases."
Well...the comment made me do some math.
1150 km is a funny distance to move something, but it happens to be the distance of the Trans Mountain (EDM - YVR) pipeline. Northern Gateway is actually more like 2000 km. For our purposes, longer transit distances make transport efficiency more important, but I did all the calculations based on 1150 km.
Showing your work is boring, so trust me: