The actor had a big part to play in the challenging 40th anniversary broadcast as his character Cameron Murray murdered Carl King (Tom Lister) in the climax to their blackmail storyline.
Power told The Mirror: "It was hugely flattering to be asked to play such a pivotal role in the live episode, and a huge privilege to be part of TV history.
"I was so nervous on the night. On a scale of 1-10 nerves? I was at 20. But about an hour before going on air, I went cool as a cucumber. I thought, 'I won't get a chance to do this again, and I want to enjoy it'."
The truth about Carl's death currently remains a secret in the village as everyone thinks that jailed Chas Dingle (Lucy Pargeter) delivered the fatal blow, including Chas herself.
However, Power added: "It doesn't feel like [Cameron has] got away with it. He's feeling guilty about Chas, and he's no longer in the family unit with Debbie and Sarah. He's a shell of himself, and he's slowly going insane."
Emmerdale airs weeknights on ITV1.