interesting advancements in energy efficiency are in the news

a new supertanker, whose four large sails will cut down average fuel consumption by nearly 10%

https://newatlas.com/marine/new-aden-supertanker-sails/

Railroad book author Walter Simpson discovered that the maximum fuel-to-rail energy efficiency of modern diesel-electric locomotives is 40%.

The maximum efficiencies of turbine-powered locomotives and steam locomotives were 12% and 8%, respectively. 

Steam locomotives, despite their awesome power and presence, waste a minimum of 92% of the energy in the coal they consume.

https://buffalonews.com/opinion/my-view-how-a-childs-fascination-with-trains-became-a-book-series/article_8fcbfe12-3dc1-11ed-945e-c36edc5a95aa.html