I was excited to make this build as soon as I heard what this exotic did. Unfortunately, throwing duskfield grenade does not activate the energy converter mod effect. CWL stacks are not consumed, and super energy is not granted. Swapping to glacier or coldsnap grenades (without unequipping renewal grasps) allows you to activate the mod, and strangely enough, loading into an activity with glacier or coldsnap grenades and SWAPPING to duskfield grenades will (sometimes) allow duskfield grenades to activate energy converter, but this is reset to the bugged behavior if your team wipes. Speculation time. To me, this reads like equipping duskfield grenades with renewal grasps and energy converter leads to the grenade having too many properties, and some are disabled no matter what, but the exotic and default effects take precedence over the mod effect when your loadout is evaluated/reevaluated; changing things within a loaded instance is what lets you haphazardly change what effects take precedence (perhaps the reduced damage from enemies in the aoe doesn't work when energy converter activates, for example) but default disabling behavior is refreshed when you load/reload into an instance.