You Do Need power plug adapter while traveling from Namibia to Åland Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Åland Islands are C and F and in Namibia are D and M. This is how they look like.

Namibia

In Namibia, outlets of type D and M are in use.

Type D

Type M

Åland Islands

In Åland Islands, outlets of type C and F are in use.

Type C

Type F