You have two choices, either
1) organize a new fixed term contract
2) Don't bother with a new contract as the tenant has already acquired the right to remain in the property for up to 4 years without signing a further contract. This is then called a Part 4 tenancy.
A fixed term sort of guarantees the tenant will stay for another year but he can get out of it by assigning the lease though he should find the new tenant at his expense. However, while a fixed term lease is in existence, you have no right to regain possession of the property until the lease expires.
With a Part 4 lease, the tenant may leave with, in this case, 42 days notice and does not have to find a new tenant. A new tenant would be a new tenancy and accordingly, would have to be registered again with the PRTB.
On an aside not, as you are not living in Ireland, if you do not have someone (family, friend or agent) looking after your affairs, the tenant should be with-holding 20% of the rent and forward it to the Revenue as a contribution for your tax liabilities.
Also, you are required by law to have an emergency contact point (usually a phone number) at which the tenant may contact you at any reasonable time. Any verbal contact should also be followed up with a written communication so the tenant (and the PRTB) must have your/agents address. This applies especially to legal documents such as a Notice of Termination or claims with the PRTB.
EDIT: On reading your post again, I understand that you have an agent - an Estate agent. However, the two choices remain - another fixed term or Part 4 tenancy.