You Do Need power plug adapter while traveling from Libya to Pitcairn Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Pitcairn Islands is I and in Libya are C and L. This is how they look like.

Libya

In Libya, outlets of type C and L are in use.

Type C

Type L

Pitcairn Islands

In Pitcairn Islands, outlets of type I are in use.

Type I