Power supplier ESB said that engineers had worked into the night to try and restore as many homes as possible, but the scale of the damage was making the task difficult.On Wednesday, severe storms led to the provinces of Munster, Leinster and Connaught being placed under red alert and more than 260,000 homes were left without power.Engineers were back out at early dawn on Thursday assessing the damage.ESB spokesman Virgil Porter said: "The reality is, given the scale of the storm and the magnitude of what faces us, it is going to go into three, possibly four days in terms of outages for customers that are out there."He said that Wednesday was all about making things safe, about getting lights down."Even into today, we are still doing that so public safety was the priority goal for day one and certainly into today."The south of the country was worst affected - the highest waves ever recorded in Irish waters were registered south of Cork, reaching 25 metres and there was disruption to travel with ferry crossings cancelled, and flights delayed or diverted.Met Éireann said that Wednesday's storm was one of the top five worst on record.Forecasters also predict the current unsettled spell will continue on Friday and Saturday with heavy rain and very strong gales.Northern Ireland Electricity has sent a number of their crew members down south to help with the restoration operation.Fifty lines crew and 20 members of the tree maintenance team travelled down along with specialised equipment on Thursday morning to assist ESB. They are being sent to the worst affected areas and are expected to be needed for the next three to five days.Kevin McDowell, of NIE, said: "In this business we need to respond quickly so it's good to help out colleagues when we can - it only takes the wind to change for us to have to call in those favours."Over the last few years and particularly in last year's snow storm, we benefitted greatly from help from GB and RoI so we understand the need for mutual aid following this type of weather."Meanwhile, motorists are being urged to take extra care as debris may be a problem on the roads in the aftermath of the gales.A statement from Gardaí said: "Road conditions are hazardous due to black ice and recent show showers throughout the country. Fallen trees and debris may be encountered on many roads."Gardaí also issued an appeal for members of the public to check on the welfare their elderly neighbours, or those living alone."Please be neighbourly and don't assume others will," the statement concluded.Drivers are urged to slow down and be aware of crosswinds. There are also reports of snow and black ice in some areas.Aoife Carragher, from AA Roadwatch, said: "This morning we woke up to find snow and ice falling on already very wet roads so that's not helping things. There is a lot of debris from yesterday and obviously the icy conditions are making things a lot worse."The local authorities are working to clear trees from many regional and local roads."She advised that the main routes should be used as they are most likely to be cleared.