The new mods, +5 energy. They are like damage mods (^50 v50 vshexed w/hexed etc.) They are still pretty rare gold drops, but there are crafters for them (Not saying the crafted ones are nearly as nice as the gold ones) Only crafter is after the last mission in factions.
max +5 energy gold daggers with 8-9 req sell for pretty cheap even now. can probably pick one up for a bit under 100k
Pretty sure +5 energy is available on crafted weapons now for 5-10k
The maximum energy possible while weilding a pair of +5 energy daggers and shrouded armor is 37. You can equip a staff or a onehand/offhand and bring this number up higher, but I think you specifically wanted max energy while using Daggers.