Power companies have been accused by MPs of displaying "utter complacency" and a lack of real concern for customers over delays in restoring electricity to storm-hit homes over Christmas.

Appearing before the Commons energy committee on Tuesday, bosses of the UK's energy distribution firms defended the length of time it took to restore power to homes.

Basil Scarsella, chief executive of UK Power Networks, told MPs the combination of the storms' severity and their national reach meant "tried and tested" plans struggled to cope.

He said: "We have a tried and tested system that comes into play when there's an emergency such as that. You're correct: we knew that there were storms. We have a methodology that estimates the damage expected on the network based on the wind speeds.

"But the wind speed and the weather forecast escalated significantly on the Sunday and went from 40-50mph winds on the Friday to 50-60mph for our area, and escalated to 70-80mph on the Sunday.

"But notwithstanding that, we managed, on the Monday when it hit, to have all our workforce pretty much on deck, and our estimation of the damage was pretty accurate.

"What we did not estimate accurately was the duration of strong winds, which resulted in significantly more severe damage."

He added: "The other issue was that this was a national storm and it lasted over two or three days. There is a well-tested mutual aid system, which enables any of us to call on our colleagues to send additional resources. But because of the severity of the storm and the national nature of the storm, we were not able to provide additional resources to other networks or indeed receive additional resources."

More than 150,000 homes were cut off after strong winds, torrential rain and flooding caused damage to power networks, and many were left without electricity for up to five days.

Tim Yeo, the committee chairman, lambasted the bosses for failing to show "any expression of real concern for your customers".

He said: "I have to say, after 45 minutes, the tone of this discussion and its contents has been utter complacency from all of you. The trade body can't provide the most basic information on a totally predictable question.

"You have lacked any expression of real concern for your customers. It's absolutely typical of a monopoly, particularly monopolies whose charges are not very visible to the customers who have to pay them."

Yeo warned the witnesses to "step your act up" if they wanted to impress the committee.

Mark Mathieson, managing director of SSE's electricity networks, told the committee: "It was just the impact of the event. It was a massive event. Certainly, we haven't seen damage like this in the south [since] the early 90s and even … the great storm of 1987.

"I think the one thing I would say – and I've been in this industry for 25 years – we as an industry clean these events up much quicker than we used to.

"But we also recognise the impact that has on customers. We are sorry, and I did go out to communicate with customers that we were sorry that they were off.

"To get to the area and fix faults, in some circumstances when you've got damage like that, when you've got devastation like that, it unfortunately takes time. But that's where we go the extra mile. I know it's not the same as being at home with the power on, but we were offering accommodation and hot meals."

This month the energy secretary, Ed Davey, said the government was looking to introduce a single emergency number that people could call irrespective of where they live to report power cuts.

David Smith, chief executive of the Energy Networks Association, told the committee that planning for the 999-style emergency number to deal with such situations was in its early stages.

He said: "There are some technicalities around it. We need to work those through. We are doing those now. We have got a piece of work ongoing and we are delivering that within the next month."

Yeo concluded the session by saying: "I've heard nothing at all this morning which reassures me that you are taking this problem seriously enough to deal with the concerns of millions of your customers. There is no sense of urgency in what you said about any plans to step up your capacity to respond to severe weather even though we now have quite clear warnings that extreme events are likely to take place more frequently in future.

"You have managed to make the secretary of state look ridiculous in his claim that there is going to be a three-digit number that customers can use. You've failed to demonstrate, in my view, adequate concern for the plight of your customers. That's characteristic of monopolies whose activities are not very effectively scrutinised by anybody until now. And frankly, if your customers had the capacity or the freedom to switch to an alternative distributor I am sure that millions of them would be doing so as we speak.

"I have to conclude that you are exploiting your privileged monopoly position and you have displayed a neglect of your customers which I personally find absolutely astonishing. But thank you all for coming in."