You Do Need power plug adapter while traveling from Peru to Ireland (Eire).

Here is Why You Need An Adapter

The outlet and plug type used in Ireland (Eire) is G and in Peru are A, B and C. This is how they look like.

Peru

In Peru, outlets of type A, B and C are in use.

Type A

Type B

Type C

Ireland (Eire)

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

Type G