You Do Need power plug adapter while traveling from Dominican Republic to Northern Ireland.

Here is Why You Need An Adapter

The outlet and plug type used in Northern Ireland is G and in Dominican Republic are A, B and C. This is how they look like.

Dominican Republic

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

Type A

Type B

Type C

Northern Ireland

In Northern Ireland, outlets of type G are in use.

Type G