Hi OP,
I used BOI early repayment calculator
personalbanking.bankofireland.com
Assuming you have 28 years left on the mortage and you paid 150k lump sum, you would reduce your term by just over 8 years. So, instead of being mortgage free when you're 62, you'd be mortgage free when you're 54....
I used BOI early repayment calculator
Overpayment Calculator - Manage My Mortgage - Bank of Ireland
We offer you the flexibility to overpay your mortgage. Use our overpayment calculator to see what savings you could make.

Assuming you have 28 years left on the mortage and you paid 150k lump sum, you would reduce your term by just over 8 years. So, instead of being mortgage free when you're 62, you'd be mortgage free when you're 54....