Seed Mag­a­zine high­lights the word Negawatt:

\né-gə-wät\ n: A mea­sure of the avoided use or the con­ser­va­tion of a unit of energy.

Wikipedia goes into more detail:

By invest­ing to reduce elec­tric­ity demand instead of invest­ing to increase elec­tric­ity gen­er­a­tion capac­ity, this “vir­tual gen­er­a­tion” method can sup­ply growth of sup­ply by improv­ing the effi­ciency of exist­ing elec­tri­cal equip­ment rather than by build­ing new power stations.

Energy con­sumers may also reduce energy con­sump­tion dur­ing peak, hours to “gen­er­ate” negawatts — hypo­thet­i­cal trade­able units of saved energy.

A sim­i­lar con­cept applies to energy, with poten­tial con­sumers being rewarded for low­er­ing con­sump­tion at any time, rather than just at peak times: this could then be labeled nega­joules or negawatt-hours.