With the Content-Aware Spot Healing tool you can easily remove power lines from images.
Simply follow these steps: Using the Pen tool, create a path that follows the powerline you want to remove.
Then select the Spot Healing Brush tool and click on the Content-Aware option in the Options Bar.
Change the brush size to about twice the width of the wire and in the Paths panel (Window > Paths), go to the flyout menu (four-line icon on the top right), choose “Stroke Path” and select the Spot Healing Brush from the drop-down.
This will stroke the path and remove the power lines!
Watch the video tutorial here: