Travel Technology - In Seat Power - UK plug with travel adaptor possible?

Hi,

I will be flying with Etihad soon. I understand that for the aircraft that I'm on, in seat power is available.

Since I have a UK power plug (3 prongs), is it possible for me to connect my UK plug to a travel adaptor (one that has all sorts of plugs), and connect that to my in seat power?

Also, does anybody know if in seat power in Etihad Airways Economy is actually free or payable?

Thanks!