Can the Coop Light be used independently without having the automatic door closing feature?

The Coop Light cannot be used without an Automatic Coop Door. The Coop Light can only be powered by connecting it to the Control Panel of the Automatic Coop Door. 

You could still turn the light on and off manually when plugged into the control panel, but it will still work alongside the Automatic Coop Door's features, eg. the light will turn on 5 minutes before the door is scheduled to close.