Overall gas demand remains unchanged in the first half of the year, while upward demand for gas in transport continues

• Overall gas demand fell by 9% month on month in June 

• Gas generated 36% of electricity in June and 39% across H1 2025

• CNG demand rose 26% year-on-year in June, reducing emissions in transport 

Gas Networks Ireland’s latest gas demand statement shows that overall gas demand in the first half of 2025 remained broadly consistent with the second half of 2024. During this period, gas accounted for 39% of Ireland’s electricity generation, compared to 33% from wind. 

In H1 2005, gas’s contribution to power generation peaked at 90% and never dropped below 11%, underscoring its critical role in maintaining stability and reliability in the electricity system amid fluctuating renewable energy output.

June

In June overall gas demand fell by 9 per cent in June compared to May and by 7 per cent compared to June 2024, during what Met Éireann described as the fourth warmest June on record, albeit wetter and duller than average across much of the country¹.

Gas generated 36 per cent of Ireland’s electricity in June, down from 40 per cent in May and 42 per cent in June 2024. While gas’s contribution peaked at 90 per cent and never dropped below 14 per cent, wind accounted for 30 per cent of electricity—up eight percentage points from 22% in May—and ranged from less than 1 per cent to a peak of 75 per cent².

Ireland’s energy system’s reliance on gas during low renewable output was evident between 9^th and 14th June, when gas supplied 42 per cent of electricity and wind supplied 23 per cent. A similar pattern occurred from 29^th to 30th June, when gas generated 58 per cent and never dipped below 31 per cent². 

Sectoral demand for gas

Gas demand across most sectors saw year-on- year declines in June, with notable reductions in the residential (-21%), leisure/sports arenas (-17%) and retail (-14%) sectors, largely driven by the warm weather which reduced heating needs. 

However, compressed natural gas (CNG) demand grew by 26 per cent year-on-year. Made by compressing natural gas down to less than 1% of its volume, CNG is a more environmentally friendly fuel than petrol or diesel and provides the Irish haulage industry with a cleaner alternative fuel option.  Fuelling with CNG can reduce a heavy good vehicle’s emissions by up to 22%, and with CNG suppliers now sourcing gas via renewable sources, BioCNG can turn a HGV into a carbon neutral vehicle, providing the Irish haulage industry with a clean alternative fuel option.  

Gas Networks Ireland’s Director of Strategy and Regulation Edwina Nyhan, said 

“While overall gas demand typically dips over the summer months, it remains central to the resilience of Ireland’s energy system. June’s data again illustrates how gas consistently supports electricity generation during periods of low wind, helping to keep the system secure and balanced.

The steady growth in demand for CNG, including a 26 per cent increase in June year on year, reflects continued momentum in decarbonising the transport sector. This progress is further supported by recent developments such as the opening of a new public CNG station in Dublin and the launch of the GRAZE vehicle grant scheme, which is already generating strong interest from fleet operators.

At the same time, we are making important strides in supporting the build out of the biomethane industry, including the recent signing of a Memorandum of Understanding with CycleØ to help connect new biomethane production sites to the gas network.”

^{1Climate Statement for June 2025 - Met Éireann - The Irish Meteorological Service}

^{2 All peak and low measurements recorded over a 15-minute resolution}