EirGrid plans to spend around €1 billion to overhaul the underground electricity supply routes in Dublin, replacing ageing cable infrastructure laid in the 1970s and 1980s with a modern network, fit to cope with increased demand and the fluctuations caused by the shift to renewable energy.
“The security of the system is under pressure at the moment,” says Enda Geraghty, Dublin programme manager with EirGrid. “As we move to decarbonise the system, we move to a more inconsistent energy source which is wind and to a degree solar as well.”
The shift to wind power is a major opportunity for Ireland, Geraghty says. But since the supply fluctuates due to the weather, it creates a balancing act for EirGrid – the state-owned electric power transmission operator – to ensure there is a constant supply of power at all times.
Demand for electricity is booming in Dublin for lots of reasons, he says. There is a switch towards electrical heating, a move towards electrical transport, and the demands of large business customers and of a growing population.
Put it all together and the modelling shows that the city’s major underground electrical supply lines won’t be fit for purpose by 2030, he said on a Zoom call on Tuesday.
Replacing the cables shouldn’t mean power outages, he says, but it will cause some traffic disruption since they will be laid under roads.
Balancing the Grid
A lot has changed since Dublin’s major electricity supply networks were laid, says Geraghty.
Demand for electricity in Dublin is increasing rapidly, as is the population.
“Whether we had a single extra data centre or a single extra offshore connection we still need these new cables,” he says. “It’s an essential project.”
The modelling for 2032 shows that the circuits will be overloaded by then, says Geraghty. “They will become not be fit for purpose by 2030,” he says.
So the target is to finish upgrading the system by then. That poses challenges in terms of competition for construction workers, designers and engineers, he says.
Ireland has a major opportunity to benefit from wind energy, says Geraghty. “We are at a huge advantage here in Ireland and should likely be a net exporter of energy as we move towards 2050.”
In 2020, wind energy met 36 percent of Ireland’s electricity demand, according to the Sustainable Energy Authority of Ireland.
Ireland’s Climate Action Plan 2021 targets connecting at least 5GW of offshore wind to the grid by 2030.
EirGrid also has plans to build an underwater system to link up the Irish electricity supply with France. This would allow Ireland to export wind energy.
The shift to renewables means learning to balance major spikes in demand with fluctuating supply, says Geraghty.
Any unplanned outages can be disastrous for a city, he says. In London recently a quarter of the city lost power very briefly due to a strike on an offshore platform, he says. “It was only a 20-millisecond event but it took 24 hours to get the tube back up and running.”
To deal with the fluctuations in supply the ESB uses innovative technology, says Geraghty. “Moving our systems into smart systems so we can anticipate what is about to happen on the grid to ensure we have enough power.”
The Electrical Highway
Eirgrid is a state-owned company that was established separately from the ESB in 2006, says Geraghty. It operates the electricity network grid.
When Dublin’s underground electricity cable infrastructure was laid decades ago, it was excellent for the time, he says.
The city’s major electricity supply stations are located at Carrickmines, Inchicore, Belcamp, Finglas, North Wall and Poolbeg.
They need to be upgraded and many of the cables that run between them need to be replaced. Also, a new cable must be laid between Carrickmines and Inchicore.
“As we move to 80 percent renewables we have to have those highways up and running because renewable energy is just not stable,” says Geraghty.
The works shouldn’t lead to power outages, says Geraghty. “If there was a crash on the M50 people can always tail off at Blanchardstown, or wherever, and use the regional roads or the local roads.”
Likewise, if the local power highway is cut off temporarily for these works, the ESB can still use other smaller routes to send out electricity to homes and businesses in the local area.
The works will lead to some traffic disruption, says Geraghty, because the cables have to be laid underneath the roads. The exact routes haven’t been decided yet, he says.
EirGrid is collaborating with other companies to try to minimise that disruption, said Sinead Dooley, head of public engagement at EirGrid on a recent webinar.
If another company is planning road works in an area EirGrid will carry out its works at the same time. “There is nothing worse than if one utility opens up a road and then in two months time someone else is back doing the same thing,” she says.
Once draft routes have been identified, EirGrid will start active community engagement by contacting residents’ groups, community groups, sports clubs and business organisations in areas affected, says Dooley.