I can't tell you of the top of my head but by pressing, I think, colon little t (:t), it'll change the display and one of the options spurred you the energy cost of your last action.
It might be a different combo but you can check that in the built in moves list section by pressing "?" Then "k" for keybindings.
Completed: All Races, All Classes. Twice.
Fastest Run: Dwarf Mindcrafter - 34803 turns. No wand of tele.
Challenge Games: C- CK (stupid ending), Platinum Girdle x10, Westside Story, Team Teleport - illiterate troll barb, Scroll of Omnipotence obtained
ULE - DE Archer