You Do Need power plug adapter while traveling from Guinea-Bissau to Ireland (Eire).

Here is Why You Need An Adapter

The outlet and plug type used in Ireland (Eire) is G and in Guinea-Bissau is C. This is how they look like.

Guinea-Bissau

In Guinea-Bissau, outlets of type C are in use.

Type C

Ireland (Eire)

In Ireland (Eire), outlets of type G are in use.

Type G