A quarter of all energy used in Ireland is consumed directly in homes. Second only to transport, and more than is used by industry.

Significant energy use of the residential sector

The residential sector accounts for a quarter of the energy used in Ireland. It is also responsible for a quarter of the energy-related CO2 emissions. From 2006 to 2014 there were significant reductions in the amount of emissions from homes. Since 2014 this trend has reversed and carbon dioxide emissions have started to increase.

The graphs below show trends in energy use in homes, broken down in different ways.

Final residential energy demand

Year Energy Demand Weather Corrected Energy Demand
2000 2504 2477
2001 2639 2604
2002 2611 2696
2003 2724 2767
2004 2843 2870
2005 2940 2998
2006 2972 3065
2007 2905 3069
2008 3149 3032
2009 3086 2967
2010 3270 2879
2011 2841 2821
2012 2726 2568
2013 2762 2592
2014 2539 2513
2015 2672 2553
2016 2704 2675
Source: SEAI

Adjusting for weather

Weather variations from year to year affect energy demand, particularly for space heating. It is useful to adjust for annual weather variations by using degree-days.

Return to growth

Weather corrected residential energy demand decreased every year between 2007 and 2012, but grew in 2013, 2015 and 2016. Between 2014 and 2016, residential sector final energy consumption increased by 6.5% (3.2% per annum).

Reasons for changes

Potential reasons for the decrease in household energy use between 2007 and 2014 include:

  • Improved thermal efficiency due to retrofitting and building regulations
  • Reduced household incomes and expenditure, due to the economic downturn
  • High energy prices

Potential reasons for the increase between 2014 and 2016 include:

  • Increasing household incomes and expenditure
  • Reduced energy prices, particularly of oil

Final residential energy demand by fuel type

  Coal Peat Oil Natural Gas Renewables Electricity
2000 286 299 915 439 17548
2001 264 288 1011 482 17579
2002 252 290 1010 476 17566
2003 239 270 1059 539 18599
2004 231 266 1094 601 19632
2005 246 273 1145 607 23646
2006 219 284 1116 632 27695
2007 208 271 1101 593 38693
2008 230 280 1197 669 41733
2009 267 272 1173 625 50699
2010 254 254 1263 710 54735
2011 230 241 1035 569 53712
2012 242 215 910 600 61698
2013 273 218 917 606 64684
2014 219 200 857 536 65663
2015 206 201 956 555 76678
2016179197100556383677
Source: SEAI

Dominance of oil

Oil has remained the largest fuel source since 2000. It accounted for 37% of all final energy used in the residential sector in 2016. The next largest source was electricity at 25%.

Between 1990 and 2000 there was a clear switch away from solid fuels used in open fires towards oil and gas central heating systems. After 2000, fuel shares became more stable. We can see a gradual increase in shares of electricity and gas and a continuing decline in coal and peat use.

Weather corrected oil and gas use

Changes in oil use were the main source of fluctuation in overall household energy demand between 2007 and 2016. Weather corrected oil use declined by 28% between 2007 and 2014 and increased by 17% between 2014 and 2016. Weather corrected gas demand decreased by 17% between 2007 and 2014. It increased by 5% between 2014 and 2016.

A likely reason for the higher fluctuation in oil use may be the greater fluctuation in oil prices. Additionally, the majority of oil-fired dwellings are in rural areas. These areas may offer greater opportunity for fuel switching to solid fuels.

Electricity

Total electricity consumption peaked in 2008. It reduced slightly between 2008 and 2016, having more than doubled between 1990 and 2008. There is evidence that the growth of large household appliances is levelling off. At the same time, there has been an increase in appliance efficiency. Additionally, there was an increase in electricity prices over the period.

Renewables

Between 2005 to 2016 renewable energy grew from a low starting point, mostly from wood pellets.

Final energy by end-use

Electricity,Space Heating,67
Electricity,Water Heating,79
Electricity,Cooking,47
Electricity,Lighting and Appliances,459
Electricity,Other,25
Gas,Space Heating,405
Gas,Water Heating,145
Gas,Cooking,13
Solid Fuels,Space Heating,347
Solid Fuels,Water Heating,34
Oil,Space Heating,780
Oil,Water Heating,219
Oil,Cooking,1
Renewables,Space Heating,53
Renewables,Water Heating,30
Source: SEAI

Challenge of gathering end-use data

It's important for us to understand how energy is consumed in homes. In particular, we need information on the portion of energy consumed for the main end-uses. These include space heating, water heating, cooking, lighting and electric appliances.

We cannot collect data on energy by end-use in the same way as it is by fuel type. For example, it's not possible to use electricity meter data to tell the share used for water heating.

A new model for estimation

To estimate the split, SEAI developed a model of household energy consumption. We based it on data from the BER database. Our estimation for 2016 is: 61% of all energy used in households was for space heating, 19% for water heating, 17% for lighting & appliances, and 2% for cooking.

Energy related CO₂ emissions

 CoalPeatOilNatural GasElectricity
2000 1146 1276 2777 10444913
2001 1060 1229308011535427
2002 1014 1240306411355427
2003 958 1157321812834699
2004 928 1140330114294683
2005 989 1170346714434773
2006 877 1216336415044815
2007 835 1163332514144517
2008 922 1195361015934666
2009 1072 1161352914924241
2010 1020 1085379216974527
2011 922 1034310713604050
2012 972 915 2733 1430 4301
2013 1099 929275114223712
2014 882 855 2569 1272 3505
2015 831 858 2863 1323 3665
2016 721 842 3008 13173801
Source: SEAI

Second highest source of CO2

The residential sector accounted for 24% of energy-related CO2 emissions in 2016. This includes upstream electricity emissions. The residential sector was the second largest source of CO2 emissions after transport (which accounted for 37%).

The trend for residential energy-related CO2 emissions follows the trend in energy consumption. Residential energy related CO2 emissions increased in 2015 and 2016, after a decrease between 2010 and 2014.

CO2 emissions by fuel source

The graph shows residential energy related CO2 emissions split by fuel source. Oil, gas, coal and peat are burned directly within the home. We also factor in CO2 emissions from electricity generating stations producing electricity for homes.

The emissions from electricity use in the home are the largest source of emissions by fuel type. They account for 39% of total residential CO2 emissions. Oil use was the next largest source, accounting for 31%. If we exclude electricity, oil accounted for 51% of residential CO2 emissions.

Final energy per dwelling

  Non-electric energy Non-electric (Weather corrected) Electricity
2000 18571 18326 5206
2001 19136 18822 5374
2002 18584 19330 5142
2003 18646 19012 5257
2004 18758 18979 5359
2005 18830 19289 5303
2006 18109 18814 5528
2007 17150 18366 5377
2008 18281 17437 5547
2009 17633 16792 5160
2010 18290 15606 5302
2011 15007 14872 5023
2012 14215 13164 4896
2013 14485 13365 4764
2014 13003 12831 4591
2015 13740 12962 4669
2016 13885 13885 4638
Source: SEAI

In 2016 the average dwelling consumed a total of 18.5 MWh of energy – 78% from direct fuel use and 22% from electricity. Weather corrected final energy use per dwelling remained constant between 2000 and 2005. It fell by 29% between 2005 and 2014, but increased again by 5% between 2014 and 2016.

Energy related CO₂ emissions per dwelling

  Non-elecitrical Electricity
2000 5.1 4
2001 5.2 4.3
2002 5 3.8
2003 5 3.5
2004 5 3.4
2005 5 3.4
2006 4.8 3.3
2007 4.5 3
2008 4.8 3
2009 4.6 2.7
2010 4.7 2.8
2011 3.9 2.5
2012 3.6 2.6
2013 3.7 2.2
2014 3.3 2.1
2015 3.5 2.2
2016 3.5 2.2
Source: SEAI

Overall energy related CO₂ emissions

In 2016 the average dwelling emitted 5.7 tonnes of energy-related CO2. 60% of these were from direct fuel use in the home and 40% indirectly from electricity use.

The emissions of energy-related CO2 per dwelling fell by 32% between 2005 and 2016. This compares to a reduction in energy per dwelling of 23%). Emissions from energy use in households increased by 1% in 2016. This is mainly a result of increased CO2 intensity of electricity supplied. Increased oil consumption was also a factor.

Fuel use

Energy related CO2 emissions per dwelling for non-electric fuel use fell by 30% between 2005 and 2016. This is primarily a result of reduced energy consumption per dwelling.

Electricity use

CO2 emissions from electricity use reduced by 34% in the same period. This is due to reduced electricity use and reduced carbon intensity of the electricity grid.

Energy in the Residential Sector report

Our Energy in the Residential Sector 2018 report provides detailed data and analysis. It also offers a comparison of Irish homes to those of other EU countries.