Overall gas demand in the Republic of Ireland is forecast to increase by 4.5% over the winter months compared with last year, according to Gas Network Ireland's Winter Outlook report.
Gas Network Ireland said the increase is driven by expected rises in demand from power generation as well as industrial and commercial users.
The latest outlook confirms that Ireland has sufficient gas supply sources and adequate network capacity to meet anticipated demand under a range of scenarios.
This includes a "1-in-50 winter peak day", which is an extremely cold day that typically occurs only once every 50 years.
Today's report also notes Ireland's continued reliance on imported gas from Britain, with almost 86% of the state's gas requirements expected to be met via subsea interconnector pipelines.
"Our Winter Outlook shows that Ireland has the supply sources and network capacity needed to meet demand, including on very cold, calm days when demand is greatest," Edwina Nyhan, Gas Networks Ireland's Director of Strategy and Regulation, said.
"Gas will continue to provide the flexibility and reliability required to keep homes warm and the lights on over the months ahead," she said.
Electricity demand is also forecast to rise, today's report said.
Gas Networks Ireland said that although increased imports are expected due to the full inclusion of the new Greenlink interconnector between Ireland and Wales which went live at the end of January, and anticipated higher renewable output, gas-fired power generation is expected to grow by nearly 6% to support the electricity system during periods of high demand and low renewable availability.
17% of the country's gas demand last year was met by indigenous supply, with the remaining 83% supplied from Britain.
Meanwhile, overall gas demand increased by 19% in October compared with September, as cooler, wetter weather conditions, figures from Gas Network Ireland reveal.
The arrival of the first named storm of the winter season, Storm Amy, also led to higher energy use across homes, offices and key commercial sectors.
Although temperatures were relatively mild overall, this October was the coolest since 2020 and this contributed to increased heating needs, it added.
Today's figures show that gas generated 39% of the country's electricity in October, up from 37% in September but slightly below the 42% recorded in October last year.
Wind energy generated 36% of electricity, which was similar to September's level of 34% and October 2024's level of 35%, but wind output was highly variable during the month.
Solar contributed 2% of electricity generation, down from 4% in September.
Gas Network Ireland said that despite strong renewable contributions overall, both wind and solar output fell away almost completely at times, further highlighting the ongoing need for gas to provide flexibility and to ensure a secure energy supply during periods of low renewable generation.
Edwina Nyhan, Gas Networks Ireland's Director of Strategy and Regulation, said that October marks the point in the year when energy use can shift very quickly, and this month’s figures reflect that.
"As temperatures dipped and Storm Amy brought wet and windy weather, households and key sectors turned their heating back on, leading to a strong rise in gas demand. Gas also remained an important back-up for the electricity system, stepping in whenever renewable generation fell away," she added.
Today's figures show that residential gas demand experienced the most significant increase, with demand soaring by 103% from September.
Several commercial and public service sectors also recorded monthly increases in gas demand including education campuses, with demand jumping by 70%, while demand in office complexes rose 55% and leisure and sports arenas up 49%.
