You Do Need power plug adapter while traveling from Hong Kong 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 Hong Kong is G. This is how they look like.

Hong Kong

In Hong Kong, outlets of type G are in use.

Type G

Åland Islands

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

Type C

Type F