More than 20,000 homes across Donegal are now understood to be in darkness.
There are outages in Glenties, Letterkenny, Falcarragh, Derrybeg, Ardara, Milford, Kilmacrennan, Lifford and numerous other places.
And the ESB has admitted that many more homes across the county could also be wihtout power as Storm Isha kicks in.
The Status Red weather alert is only beginning for Donegal and is expected to last until at least 1am.
Large parts of West Donegal is in darkness as is Inishowen.
A spokesperson for ESB Networks has warned Donegal will be hit and those left without power may well be without power all night.
The spokesperson said “Further outages overnight are expected, particularly in the Northwest, with Met Éireann wind warnings remaining in place until the early hours of tomorrow morning.
“ESB Networks continue to monitor the impact of Storm Isha closely, switching customers back remotely where possible.
“However, due to the extent damage to the network and adverse weather conditions, the majority of homes, farms and businesses currently impacted will remain without supply overnight.”