The amount of natural gas used by power plants to generate electricity was 7.4 per cent lower in 2021 compared to the previous year, mainly due to a Cork power plant being offline, according to the Central Statistics Office (CSO).
A fault at the gas-fired Whitegate power station meant that it was offline for most of 2021.
It comes after the British multinational energy company Centrica announced in July that Bord Gais Energy’s operating profits grew 74 per cent in the first half of this year to around €39 million, partly due to the return of Whitegate in December 2021.
The CSO figures on gas consumption also show that almost half of all networked gas used by households in 2021 was during January to March.
A total of 47 per cent of the total networked gas used by households was consumed in the first quarter of 2021, with 26 per cent used in April-June and 20 per cent in October-December.
This ratio is broadly in line with the breakdown in usage across previous years.
Dympna Corry, a statistician in the CSO’s environment and climate division, said that the “strong seasonal variation” in networked gas consumption by households was due to the use of natural gas for central heating.
“The January to March quarter has by far the highest consumption, at 47 per cent of the annual total in 2021,” she said.
“In contrast, July to September accounted for only 7 per cent of total residential consumption in 2021.
“Seasonal variation was less evident in other sectors, with the third quarter of 2021 accounting for 27 per cent of total usage by power plants and for 20 per cent of consumption in the non-residential sector.”
Power plants accounted for 61 per cent of the total use of networked gas in 2021 compared with 25 per cent by the non-residential sector (which excludes power plants), and 14 per cent by the residential sector, a broadly similar ratio to previous years.
The figures released on Monday also show that gas consumption by the industry and commercial sector was 2.2 per cent higher in 2021, which is the second-highest figure after 2019 since the data series began in 2012.
The total gas consumption in 2021 was 55,413 gigawatt hours, a decrease of 4.4 per cent over 2020 consumption.
CSO figures also showed that Dublin postal districts accounted for around 44 per cent of total residential consumption in 2021, followed by Dublin county, at 17 per cent, and Cork at 11 per cent.
Three counties, Donegal, Leitrim and Sligo, are not connected to the gas network.
Ms Corry said: “Figures for Kerry, Longford, Roscommon and Wexford are based on low meter numbers and have been omitted from the graph.
“Of the other counties, Mayo had the lowest median consumption in 2021 at 7,770 kWh, while Dublin county had the highest median consumption at 10,974 kWh compared with the median consumption of 10,056 kWh for all households in the State.
“Dublin postal district areas accounted for 43 per cent of both non-residential and residential meters in 2021.
“The number of non-residential meters increased by 7.6 per cent from 27,065 in 2012 to 29,127 in 2021.
“The number of residential meters has increased by 8.5 per cent from 636,928 in 2012 to 691,332 in 2021,” she said, adding that residential meters are concentrated in large urban areas such as Dublin postal districts, Dublin county, Cork, Kildare, Meath and Limerick.