ESB crews are working to restore power to 10,000 homes which are still without electricity following severe lightning strikes last night.
Transformers were struck by lightning in the south and south east of the country, causing more than 20,000 homes and businesses in parts of Waterford, Wexford, Cork and Killkenny to lose power.
ESB has said 10,000 in Waterford and south Wexford remain without electricity this morning - but crews hope to have power restored by lunchtime.
Spokesperson for ESB Networks Mike Fitzgerald said: "What's unusual about this storm is that it was so severe and so prolonged - it effectively lasted the full day. We had wave upon wave of lightning.
"We had got most of the people affected over the previous night back by the morning and were down to quite low numbers when further waves of lightning came along and took more of the system out."
Phenomenal lightning taking place earlier over #kilmacthomas #georgestown http://t.co/Ca7EvOWZOQ /via @DiamondsIRL
— Irish Weather News (@iWeatherNews) October 8, 2014