Shield Efficiency
Shield Efficiency decreases the Energy cost of Shield by 25%, according to the supplied Personal Mod table.
How it works
The Mods page classifies Personal Mods as mostly related to Jesse's abilities and says they may decrease the Energy needed to execute them. Shield Efficiency is listed with the specific effect of reducing Shield Energy cost by 25%. The source describes ability-mod effects but does not provide a comparison with Shield Boost, which separately increases Shield strength.
Read the supporting references
A focused reference to Service Weapon forms and selected named Weapon and Personal Mods. It covers form behavior, several mod effects, and cited availability or slot rules. It does not attempt complete coverage of abilities, all equipment, exact upgrade costs, or comparative effectiveness. Guidance explains the referenced mechanics; it is not a tested damage ranking. Check the stated edition and source version before applying a patch-specific detail.