Elbow pads are used to protect the elbows from grazing (thin ones) or impact (thicker ones) when landing on them from falling. They can take some of the sting of an elbow by spreading the impact. Damage to the area will still be considerable.
Another option is to consider a fullface helmet. It's biggest advantage is it will alleviate skin tearing which is a common occurance of elbows. It will also help avoid breaking the nose or cheek bone. But it wont stop the elbow's momentum which can impact the neck & also still cause a knockout.
When the pads & helmet are combined then it might be ok to spar "light" but keep in mind even a light tap can cause injury on the neck if the opponent is not conditioned or charging into the attack.
I have experience sparring, competition & reality with elbows & they have resulted in seeing two broken noses, concussions and cut faces.