On the PRA website select the "Proceed as Guest" option. On the map of Ireland you will need to zoom in on the county and local area where the property is located. Once you have the large scale area map you should be able to identify the property. When you click on it the plot turns red and some details will come up on the right hand side including the Folio number, size of plot etc.
You now have the option to buy more information in relation to the registration. You can select the "view only" option and pay just €5 by credit/debit card, fill in your e-mail address and a copy of the Folio will be e-mailed to you immediately.
From this you should be able to find who the registered owner of the property is and possibly an address if they do not reside at the named property.