The Tower Shield, as a shield, can only grant you Total Cover.
However, the Tower Shield is also a physical object in the game. Ignoring its extra game rules as a shield, if it is large enough to actually cover the doorway, the cover rules apply like they would to a pile of bricks or a door.
To determine if this will work, you'll have to ask the DM what the size of the door actually is, and what the size of the shield is. Then work out if an object the size and shape of the shield could be used to cover the entrance of the door such that you cannot go or see through it.
This is all in the realm of DM fiat. There may not be time to seal the door in combat. It may require checks. Foes on the other side may easily be able to push it aside. It may not be large enough. The effect could burst through the cover, having its damage reduced. You could be forced to be flat footed while holding the barrier up (as you cannot very well dodge while holding it up there).
But the existence of rules that state how you can use a Tower Shield to generate Cover does not preclude using the Tower Shield to generate cover in other ways. If you had a large sheet of metal that was 5' on a side, and you placed it in front of a 4' diameter hole, you'd have total cover against whatever was on the other side of the hole. If the shield is large enough to cover the doorway, you get Total Cover.
A tower shield has a hardness of 5 (+2*enhance) and 20 (+10 * enhance) HP, so it might not survive being used to soak the energy. Note that electricty and fire damage is halved, and cold is halved twice, before hardness.