A 20 minute Low Priority Queue time means that you have a history of leaving/afking in games. While it's unfortunate that this time around was apparently due to an electrical issue, this doesn't change the fact that this isn't the first time you've left/afked in a game, meaning that you've used up all of the leniency the system gave you for emergency/unexpected situations, so really have no one to blame but yourself for the position you're in right now. If you can play 5 matchmade games WITHOUT leaving or afking then you'll be taken out of LPQ, but again you have to do them WITHOUT leaving or afking in them.
Please view the Leaverbuster FAQ support article for more information regarding LPQ.