Modern societies depend on reliable and secure supplies of electricity. Electricity generation accounts for a third of all primary energy use in Ireland.
Energy flow for electricity generation
Hydro,Total Fuel Inputs,1.3 Other Renewables & Wastes,Total Fuel Inputs,6.9 Wind,Total Fuel Inputs,17.4 Natural Gas,Total Fuel Inputs,48.6 Coal,Total Fuel Inputs,13.9 Peat,Total Fuel Inputs,1.5 Oil,Total Fuel Inputs,7.5 Total Fuel Inputs,Electricity Transformation losses,41.3 Total Fuel Inputs,Gross Electricity Consumption,58.7 Gross Electricity Consumption,Electricity from Natural Gas,29.1 Gross Electricity Consumption,Electricity from Wind,18.8 Gross Electricity Consumption,Electricity from Coal,5.2 Gross Electricity Consumption,Electricity from Peat,0.6 Gross Electricity Consumption,Electricity from Hydro,1.4 Gross Electricity Consumption,Electricity from Other Renewables & Wastes,2.7 Gross Electricity Consumption,Electricity from Oil,2.8
On the left hand side are the fuel inputs to electricity generation. On the right hand side are the amounts of electricity generated by each of the fuel inputs, and the total energy lost during electricity generation. Total energy inputs to electricity generation account for approximately one third of Ireland's total primary energy supply.
There is a significant difference in the shares of electricity generated by fuel compared to the fuel inputs. This is due to the different efficiencies of generating electricity in different processes. Generating electricity in traditional thermal power plants using coal, peat or biomass has low efficiency. Electricity generated from wind and hydro is 100% efficient.
A significant portion of the energy used to generate electricity is lost before the electricity reaches the final end-user, through a combination of transformation losses, own use of electricity by power plants, pumped hydro storage losses and transmission losses.
Primary inputs to electricity generation
Primary energy input to electricity generation; ktoe,Gas,Coal,Peat,Oil,Wastes Non-Renewable,Renewables,Net positive Electricity Imports 2005,2043.870796,1422.483593,496.1703559,793.5598546,0,179.7047604,175.7969 2006,2411.17038,1216.991736,462.3260891,686.4884217,0,233.3979827,152.8974947 2007,2736.918252,1171.527658,457.1368513,398.2650525,0,269.5779522,114.4101011 2008,2810.624906,991.346852,578.1464211,355.3842476,0,340.9743011,38.71861289 2009,2758.792335,774.914732,567.1166815,214.4645393,0,392.6914228,65.68277855 2010,3024.828462,867.5016886,491.00261,137.4914351,0,368.0196769,40.44803712 2011,2498.50672,913.0709869,480.0591824,54.76759499,0,516.0952276,42.14817722 2012,2269.759926,1160.110473,557.3129815,55.88477975,18.35563191,526.2242591,35.55883289 2013,2098.171246,970.369293,506.9387623,43.4514207,22.85712896,561.1613026,192.8285636 2014,1972.985938,940.3783986,549.7494641,60.27116809,24.51809655,630.8136594,184.818902 2015,1899.443686,1125.572786,554.0350396,86.22792032,24.81036339,750.1229132,57.90982 2016,2341.603245,1102.585823,521.9067377,68.40992452,24.94361537,747.7386295,0 2017,2423.458764,867.4132118,488.1809618,33.95253312,56.39093193,884.7767544,0 2018,2460.564839,489.1341954,472.9510068,34.72978413,90.71416337,1020.505149,0 2019,2521.145597,147.8663617,434.3562444,78.46154093,88.6294441,1155.115544,55.4304744 2020,2567.233833,194.7209349,213.8325065,107.1518969,93.12891048,1316.475174,0 2021,2342.570103,672.7857021,71.44450532,359.9100594,88.90032625,1151.20159,136.5330075
The graph shows the trends in primary energy supply for electricity generation broken-out by fuel type and energy source.
Note that non-combustible renewable sources accounted for a higher share of generated electricity than of primary energy supply for electricity generation. This is because the thermal generation of electricity from natural gas and coal has significant energy losses, while electricity generation from non-combustible renewable sources (wind, hydro and solar) is considered to be 100% efficient.
Efficiency of electricity supply
,Efficiency of electricity supply (%) 2005,40.8 2006,42 2007,43.5 2008,44.8 2009,45.4 2010,44.5 2011,47.4 2012,45.7 2013,48.4 2014,49.1 2015,49.1 2016,47.7 2017,49.2 2018,52 2019,54.1 2020,54.8 2021,52.9
Efficiency of electricity supply is defined as the ratio of final energy use of electricity and primary energy supply for the generation of electricity.
The overall efficiency is determined by the weighted average of electricity generation from non-combustible renewable sources, such as wind, hydro, and solar (taken to be 100% efficient), and electricity from combustible sources, such as gas, coal, and biomass (which have transformation losses). The efficiency of electricity supply therefore increases as the share of non-combustible renewable sources, and as more efficient fuels and technologies are employed in thermal generation plants.
The efficiency of Ireland's electricity supply has generally improved over the last decades, due to the introduction of higher efficiency natural gas plants, the closure of older peat-fired stations, and increased direct generation from renewable sources.
 Electricity supply efficiency includes energy consumed by electricity generating plants themselves as well as transmission and distribution losses. Electricity generation efficiency ignores these losses, hence generation efficiency is higher than supply efficiency.
Electricity generated by fuel
Electricity generated by fuel type; ktoe,Gas,Coal,Peat,Oil,Wastes Non-Renewable,Renewables,Net Positive Electricity Imports 2005,995.364,549.454,210.7,287.24,0,161.115152,175.7969 2006,1185.51,506.024,183.868,243.724,0,212.8282315,152.8974947 2007,1380.958787,467.5785783,185.9480067,163.2892699,0,240.9771513,114.4101011 2008,1437.586114,442.2002161,236.8745425,146.8928195,0,309.1997659,38.71861289 2009,1401.638184,344.3709839,226.1012315,78.93456105,0,354.1134843,65.68277855 2010,1557.524904,305.7055629,187.3898785,51.87435555,0,320.6751909,40.44803712 2011,1327.169071,339.2504073,183.1609312,20.09690908,0,466.429009,42.14817722 2012,1215.978919,432.0948691,209.6495925,20.27974005,4.278333168,452.0391294,35.55883289 2013,1129.158551,368.299872,196.2076452,16.23942398,5.630418303,483.972804,192.8285636 2014,1086.614043,340.2533336,214.6633809,22.24736987,5.985035553,549.6911399,184.818902 2015,1063.604259,419.1795188,216.5669628,35.00940629,6.36928174,676.1096912,57.90982 2016,1318.242594,403.8440934,199.338118,25.16511173,6.260816403,646.1513092,0 2017,1348.467538,313.430299,186.1366384,12.20286584,13.6999308,763.9092137,0 2018,1377.200821,185.04973,179.8016182,11.98447811,25.93658746,877.5589363,0 2019,1367.93187,43.48391121,165.7311386,24.29659243,25.34169503,1014.831111,55.4304744 2020,1396.328791,57.88928934,79.00123087,33.48982121,25.7047416,1158.216687,0 2021,1303.375547,233.7075201,27.93774004,124.9720301,27.65787803,998.7614367,136.5330075
The above chart details the generated electricity available for final consumption by end users, broken out by fuel type and energy source.
Combined Heat and Power
,CHP electricity as % 2005,2.28 2006,5.5 2007,6.14 2008,6.19 2009,6.38 2010,6.79 2011,7.1 2012,7.72 2013,7.39 2014,7.41 2015,7.49 2016,7.45 2017,7.31 2018,6.97 2019,6.64 2020,6.56 2021,6.22
In conventional thermal electricity generation, we typically lose 60% of the energy input as waste heat. Combined Heat and Power (CHP) systems use this valuable heat energy to generate both useful heat and electricity from a single combustion process. CHP plant efficiency is usually 20% to 25% higher than heat-only boilers and conventional power stations combined. Also, these plants are physically closer to the users of their generated heat and electricity, for example at hotels or factories.
Combined heat and power also avoids some of the transmission losses incurred by centralised generation.
See the download below for more information on CHP in Ireland.
CO₂ emissions intensity of electricity
Carbon dioxide intensity of electricity generated; gCO2/kWh ,Gas,Coal,Peat,Oil,Wastes (Non-Renewable) 2005,201,230,100,104,0 2006,230,191,88,87,0 2007,252,177,84,49,0 2008,253,146,106,43,0 2009,265,122,111,27,0 2010,286,133,93,17,0 2011,243,145,94,7,18 2012,222,187,111,7,18 2013,203,156,102,5,21 2014,189,148,109,8,23 2015,177,171,104,10,22 2016,210,164,97,8,22 2017,212,127,89,4,21 2018,210,70,81,4,22 2019,211,20,73,9,23 2020,214,27,37,12,20 2021,188,89,12,39,20
Trend in electricity CO2 intensity
This chart shows the CO2 emission intensity of Ireland's electricity supply, which is measured in gCO2/kWh. The stacked bars show the share of CO2 emissions by fuel for each kWh of electricity supplied in Ireland. It is important to note that the stacked bars in the graph represent the contributions of different fuels to the overall CO2 intensity of Ireland's electricity supply, not the CO2 intensity of the individual fuels themselves.
The CO2 intensity of electricity generation fell to a historic low in 2020, before increasing slightly in 2021 due to an increase in emissions from coal and, to a lesser extent, oil. The dramatic overall improvements in annual CO2 emission intensity, as seen in the figure above, are due to reductions in the use of coal for electricity generation, and increased generation from zero-carbon renewable sources.
Over the longer term, there has been a shift away from coal and oil, two of the fuels with the highest CO2 intensity. These fuels have been replaced by a combination of high efficiency gas combined cycle gas turbine (CCGT) generation, and zero carbon renewables. Imported electricity is also considered as zero carbon from Ireland’s perspective as emissions are counted in the jurisdiction in which they are emitted.
Energy in Ireland
See the download below for more information on electricity in Ireland's National Energy Balance