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,1.80
Other Renewables & Wastes,Total Fuel Inputs,7.50
Wind,Total Fuel Inputs,22.10
Natural Gas,Total Fuel Inputs,57.10
Coal,Total Fuel Inputs,4.30
Peat,Total Fuel Inputs,4.80
Oil,Total Fuel Inputs,2.40
Total Fuel Inputs,Electricity Transformation losses,39.40
Total Fuel Inputs,Gross Electricity Consumption,60.60
Gross Electricity Consumption,Electricity from Natural Gas,30.80
Gross Electricity Consumption,Electricity from Wind,21.90
Gross Electricity Consumption,Electricity from Coal,1.30
Gross Electricity Consumption,Electricity from Peat,1.70
Gross Electricity Consumption,Electricity from Hydro,1.80
Gross Electricity Consumption,Electricity from Other Renewables & Wastes,2.50
Gross Electricity Consumption,Electricity from Oil,0.70
Source: SEAI

Electricity generated

On the left hand side are the fuel inputs to electricity generation. Natural gas was the largest energy input, followed by coal and wind. 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. Natural gas was responsible for the largest share of electricity generated, but wind was the next largest share, ahead of coal.

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.

Generation efficiency

Electricity transformation losses accounted for 39.3% of all fuel inputs in 2020. This means that 60.7% of all the energy used to generate electricity ends up as electricity.

Primary inputs to electricity generation

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Primary energy input to electricity generation; ktoe,Gas,Coal,Peat,Oil,Wastes Non-Renewable,Renewables,Net positive Electricity Imports
2005,2044,1422,496,794,0,180,176
2006,2411,1217,462,686,0,233,153
2007,2737,1172,457,398,0,270,114
2008,2811,991,578,355,0,341,39
2009,2759,775,567,214,0,393,66
2010,3025,868,491,137,0,368,40
2011,2499,913,480,55,0,516,42
2012,2270,1160,557,56,18,526,36
2013,2098,970,507,43,23,561,193
2014,1973,940,550,60,25,631,185
2015,1899,1126,554,86,25,750,58
2016,2342,1103,522,68,25,748,0
2017,2423,867,488,34,56,885,0
2018,2461,489,473,35,91,1020,0
2019,2521,148,434,78,89,1154,55
2020,2567,195,214,107,93,1318,0
Source: SEAI

The graph shows the primary energy inputs to electricity generation by fuel type.

Importance of natural gas

Gas accounted for 57% of energy inputs to electricity generation in 2020. Natural gas (NG) has been the largest input to electricity generation since the late 1990s, but its use declined after its 2010 peak of 61%, partly because of increased wind generation. Natural gas's share then increased in 2016. That was partly due to increased electricity exports to the UK and reduced generation from wind and hydro in 2016. Since 2016, the year-on-year increases in natural gas use result from decreases in overall use of other fossil fuels (coal, peat and oil) and electricity exports (except 2019).

Other fossil fuels and renewables

Coal and peat accounted for 9% of fuel inputs to electricity generation in 2020. 29% of all energy inputs to electricity generation were from renewable sources in 2020. Oil had been almost phased out of electricity generation, falling to 0.7% input in 2017. Since then, oil inputs have at least tripled to over 2.4% in 2020.

Electricity imports and exports

Electricity can be imported or exported between Ireland and the UK over interconnectors. Ireland changed from being a net importer to a net exporter of electricity in 2016, continuing to be a net exporter every year except 2019. These electricity exports mean increased quantities of energy required for electricity generation in Ireland.

Efficiency of electricity supply

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,Efficiency of electricity supply (%)
2005,40.8
2006,42
2007,43.6
2008,44.8
2009,45.5
2010,44.5
2011,47.4
2012,45.7
2013,48.4
2014,49.1
2015,49.1
2016,47.7
2017,49.2
2018,52.0
2019,54.1
2020,54.7
Source: SEAI

Generation efficiency and supply efficiency

Electricity supply efficiency differs from electricity generation efficiency as it includes:

  • Losses from transmission and distribution of electricity on the network
  • Consumption of electricity in power plants which are considered as losses

As it includes these losses, efficiency of supply is less than efficiency of generation.

Improvements in efficiency

Conventional thermal power plants have low generation efficiencies. Before 2000, electricity was produced mostly from these generators and supply efficiency was less than 35%.

The supply efficiency began to improve after the year 2000 due to two factors. The first was the commissioning of modern gas-fired turbines. They have higher generation efficiencies of 50-55%.

The second is the growth in wind-powered electricity. Wind-powered electricity generation does not consume fuel, and so is considered 100% efficient. Despite this improvement, in 2020 the supply efficiency was just under 55%. This means that 45% of all the primary energy used to generate electricity is lost before the electricity reaches the user.

Electricity generated by fuel

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Electricity generated by fuel type; ktoe,Gas,Coal,Peat,Oil,Wastes Non-Renewable,Renewables,Net Positive Electricity Imports
2005,995,549,211,287,0,161,176
2006,1186,506,184,244,0,213,153
2007,1330,473,187,165,0,240,114
2008,1438,442,237,147,0,309,39
2009,1402,344,226,79,0,353,66
2010,1558,306,187,52,0,321,40
2011,1327,339,183,20,0,466,42
2012,1216,432,210,20,4,452,36
2013,1129,368,196,16,6,484,193
2014,1087,340,215,22,6,550,185
2015,1064,419,217,35,6,676,58
2016,1318,404,199,25,6,646,0
2017,1348,313,186,12,14,764,0
2018,1377,185,180,12,26,877,0
2019,1368,43,166,24,25,1015,55
2020,1396,58,79,33,26,1159,0
Source: SEAI

Importance of wind generated electricity

Natural gas is the largest source of electricity generated, accounting for 52% of all electricity generated in 2020. The amount of electricity generated from renewables grew from just 6% in 2005 to 42% in 2020. Wind was 37% of all electricity generated in 2020, second only to natural gas and five times as much as coal, peat and oil combined. Ireland has become a world leader in the grid integration of wind generation.

Non-combustible renewables such as wind and hydro make up a much larger share of electricity generated than fuel inputs, because, they are considered effectively 100% efficient.

Combined Heat and Power

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,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
2020,6.55
Source: SEAI

Higher efficiency

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 conbusion 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. In 2020, 6.55% of Ireland's electricity was generated by CHP.

See the download below for more information on CHP in Ireland.

CO₂ emissions intensity of electricity

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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
2011,243,145,94,7,0
2012,222,187,111,7,2
2013,203,156,102,5,2
2014,189,148,109,8,2
2015,177,171,104,10,2
2016,210,164,97,8,2
2017,212,127,89,4,4
2018,210,70,81,4,7
2019,211,20,73,9,7
2020,214,27,37,12,7
Source: SEAI

Trend in electricity CO2 intensity

Carbon dioxide (CO2) intensity of electricity has reduced since the 1990s. In 1990, the CO2 intensity of the electricity grid was 896 grammes of CO2 for every kilo-Watt hour of electricity used (gCO2/kWh). The instensity was still over 800 gCO2/kWh in 2005, but then fell to 636 gCO2/kWh in 2005, and 296 gCO2/kWh in 2020.

These falls are due to increased use of higher-efficiency gas turbines, increased electricity generated from zero-carbon renewable sources, especially wind. We are also using less high-carbon intensity fuels in low-efficiency generation such as coal and oil. Oil had been almost completely removed in 2018, causing only 4 gCO2/kWh. In 2020, however, oil's intensity share had tripled to 12 gCO2/kWh.

In 2020 The carbon intensity of electricity fell from 320 gCO2/kWh to 296 gCO2/kWh. This was mainly due to a large reduction in peat use and an increase in wind generation. Peat use for electricity generation was halved between 2019 and 2020.

Coal and peat

Coal and peat continue to fuel electricity generation. In 2020, coal and peat accounted for 21% of carbon emissions from electricity generation, despite only accounting for 5% of the generation itself. This means that the carbon intensity of Irish electricity remains one of the highest in the EU, despite all our progress in using renewable energy.

Energy in Ireland

See the download below for more information on electricity in Ireland's National Energy Balance