Deep decarbonisation of Ireland's Energy System
Brian Ó Gallachóir, James Glynn, Hannah Daly, Fionn Rogan and Paul
Deane
IEA TCP ETSAP 76th Workshop, Dec 9th, CSIRO, Newcastle, NSW, Australia

Research Outputs 2019

Climate Action & Low Carbon Development Act 2015
3. Low carbon transition
• National mitigation plan shall have regard to … policy of the Govt on climate
change
National Policy Position April 23 2014
• an aggregate reduction in carbon dioxide (CO2) emissions of at least 80%
(compared to 1990 levels) by 2050 across the electricity generation, built
environment and transport sectors; and
• in parallel, an approach to carbon neutrality in the agriculture and land-use
sector, including forestry, which does not compromise capacity for sustainable food
production.

Ireland’s Carbon Budget (National Policy Position)
0
10
20
30
40
50
1990 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050
MtCO2
ETS CO2
Non-ETS CO2
Carbon Budget
2015-2050
= 998 Mt CO2
CO2 emissions =
20% of 1990
Curtin J. deBruin K., Hanley E. and Ó Gallachóir B. 2017 Energy Modelling to inform the National Mitigation Plan.
Report to DCCAE, May 2017. Available from here

‘Equitable’ Carbon Budgets for Ireland
Global carbon budgets
• 590 Gt CO2 – 1240 Gt CO2 for 66% probability of limiting to 2° rise
• 200 Gt CO2 – 700 Gt CO2 for 50% probability of limiting to 1.5 ° rise by 2100
National Carbon Budgets
• Ireland has 0.064% of global population
• Equitable allocation suggests 0.064% of global carbon budget
• Ireland is not in significant carbon ‘debt’ (2 Gt CO2 1751-2015) < 0.064% 3,400Gt
• 38 Scenarios considered for a range of carbon budgets and constraints
• 766 Mt CO2 (global 1,200 Gt CO2 budget)
• ……
• 128 Mt CO2 (global 200 Gt CO2 budget)
Glynn, J., Gargiulo, M., Chiodi, A., Deane, P., Rogan F., Ó Gallachóir, B., 2019. Zero carbon energy system pathways for
Ireland consistent with the Paris Agreement. Climate Policy 19:1, 30-42. Available from here

A carbon budget of 638 Mt is consistent with a 2 degrees target
Climate science quantifies a range of remaining
carbon budgets that align with different climate
mitigation ambitions.
A range of remaining global CO2 emissions
budgets (200Gt – 1,200Gt) are associated with
different probabilities of remaining within a 1.5o
to 2o global temperature increase.
These carbon budgets relate to CO2 emissions
are also vary depending on assumptions
regarding non-CO2 emissions.
For Ireland, a carbon budget of 638 Mt aligns
with a global carbon budget that assumes low
remaining non-CO2 emissions. A 376 Mt budget
assumes lower non-CO2 emissions reduction.
Time period
Carbon Budget (CO2)
Non-CO2 Paris Alignment
Ireland Global
2015-2070 766 Mt 1,200 Gt 66% prob 2o
2020-2070 638 Mt 1,000 Mt Low 66% prob 2o
2020-2070 376 Mt 590 Gt High 66% prob 2o
2015-2070 223 Mt 350 Gt 50% prob 1.5o
2015-2070 128 Mt 200 Gt 66% prob 1.5o

-10
0
10
20
30
40
50
1990 2000 2010 2020 2030 2040 2050 2060 2070
IrishEnergySystemcarbondioxideemissionsMtperannum
Historical Energy CO2
EPA Proj - With Measures
CO2-80_MSA
766 MtCO2_MSA
638 MtCO2_MSA
638 MtCO2_MSA_DA25
376 MtCO2_MSA
376 MtCO2_MSA_DA25
223 MtCO2_MSA
Historical CO2
emissions from the
Irish Energy System
Projected Irish
Energy CO2
emissions (EPA)
66% chance of 2°C
with immediate peak
in CO2
66% chance of 2°C
with 2020 peak in
CO2
50% chance of 2°C
with 2025 peak in
CO250% chance of
1.5°C with
immediate peak in
CO2
Zero Carbon
Energy
System?
Glynn, J., Gargiulo, M., Chiodi, A., Deane, P., Rogan F., Ó Gallachóir, B., 2019. Zero carbon energy system pathways for
Ireland consistent with the Paris Agreement. Climate Policy 19:1, 30-42. Available from here

A carbon budget of 638 Mt underpins this analysis
This analysis was undertaken by MaREI in response to Action 1 of Government
Climate Action Plan 2019
Evaluate in detail the changes required to adopt a more ambitious commitment
of net zero greenhouse gas emissions by 2050, as part of finalising Ireland’s
long-term climate strategy by the end of 2019 as per the advice of the
Intergovernmental Panel on Climate Change and the recommendation of the
Joint Oireachtas Committee on Climate Action.
• The analysis achieves zero CO2 emissions by 2050 and negative emissions beyond 2050.
• It implicitly assumes that separate measures apply to non-CO2 emissions. This aligns
with the current national policy position (i.e. targeting carbon neutrality in agriculture
and land use by 2050.
• We apply a cumulative CO2 budget of 638 MtCO2 between 2020 and 2070. This
constraint is based on an equitable population weighted (0.064%) carbon budget of
future emissions of 1,000 GtCO2 consistent with a 66% probability of meeting a 2°C
target with mitigation action commencing in 2020.
• Here we do not apply interim emissions pathway targets, and assume no significant
mitigation before 2020.
Net Zero GHG by 2050
=
Zero CO2 Emissions
+
Carbon Neutrality (non-CO2)
CO2 Emissions Budget
=
638 Mt CO2 2020-2070
Ireland has 0.064% of global
population
Global CO2 Budget
=
1,000 Gt CO2 2020-2070
Consistent with 66%
probability of 2°

All sectors dramatically reduce emissions by 2050
Emissions Reductions
(Mt CO2)
Electricity 240
Transport 228
Industry 155
Buildings 172
0
10
20
30
40
50
60
2017 2020 2025 2030 2035 2040 2045 2050
CO2EmissionsMt
Electricity
Transport
Industry
Buildings
Net Zero CO2

In 2050 residual emissions are compensated for by negative emissions
Other*
0.37
Services
0.55
Electrical generation
-3.29
Industry
0.24
Industrial
Processes
0.38
Residential
0.46
Transport
1.30
-4
-3
-2
-1
0
1
2
3
4
CO2Emssions(Mt)
Residual Emissions in 2050 - Net Zero Energy scenario • In the Net Zero Energy
scenario, there are residual
CO2 emissions in all but one
sector
• Residual emission from the
transport sector are larger
than residential, industry and
services sector combined
• Negative emissions in
electricity generation
compensate for the residual
emissions and allow the
energy sector to net zero
• Other* = residual CO2
emissions from energy use in
the Agriculture sector
0
Residual
Emissions
Negative
Emissions

Increase in electrification by sector
• In the Net-Zero Scenario, electrification
of end-uses gathers pace in all sectors
• To reach the net-zero target, electricity
consumption more than doubles
relative to today and to the reference
scenario in 2050
• Residential electricity demand is double
today’s level, driven by increased use of
heat pumps
• Transport electricity demand is 60 times
today’s level, driven by EVs
• The industrial sector accounts for the
largest absolute increase in electricity
demand

Blindspot 1 – Key Role of Fuels
In the Net-Zero Scenario, while
electrification is very significant, we
still use 63 TWh of fuel in 2050.
This graph masks the significant
growth in buildings and in passenger
and freight transport in the period
2010 – 2050.
Reductions in fuel use in buildings is
more than twice the reductions in
transport

Blindspot 1 – Key Role of Fuels
In 2010, most fuel
(81%) was used for
transport & buildings.
Oil accounted for 72%
of fuel use.
Bioenergy
3%
Coal
7%
Gas
18%
Oil
72%
Fuel Use
2010
103 TWh
Bioenergy
48%
Coal CCS
6%
Gas
7%
Oil
31%
Hydrogen
8%
Fuel Use
NZE 2050
63 TWh
Fuel use in 2050 continues
to be mostly in transport
and buildings (72%).
However, 62% of fuel use is
renewable fuel or low
emissions fuel
Agriculture
3%
Buildings
38%
Industry
16%
Transport
43%
Fuel Use
2010
103 TWh
Agriculture
4%
Buildings
19%
Industry
24%
Transport
53%
Fuel Use
2050 NZE
63 TWh

Blindspot 2 – Key Role of Bioenergy
• Bioenergy increases significantly
from 3 TWh in 2010 to 55 TWh in
2050.
• This represents twice the current
total annual electricity use in
Ireland.
• The most significant growth is in
transport, increasing by 22 TWh
by 2050.
• Results also point to 13 TWh
electricity generation from
bioenergy with carbon capture
and storage (BECCS).

Technology Cost Assumptions
A selection of technology cost assumptions for the transport and residential sector are included here
Annex

Residential Technology Costs
Housing
Stock
Rural
Urban
Apartment
New
Existing
Apartment – Space Heating 2020 2030
Roof-top Central Electric Chiller €81/kW €81/kW
Non-Reversible Gas Heat Pump €1228/kW €1228/kW
Centralized Solar Air Conditioner €2615/kW €2615/kW
Room Air Conditioner €254/kW €254/kW
Apartment – Water Heating 2020 2030
Solar Collector with Gas Backup €1424/kW €1424/kW
LPG Boiler €162/kW €162/kW
District Heat Exchanger for Hot Water €211/kW €211/kW
Apartment - Appliances 2020 - Standard
2020 - High
Efficiency
Combined Washing/Dryer Machine €0.55/kW €0.72/kW
Fridge/Freezers €0.75/kW €1.60/kW
Dishwashers €0.15/kW €0.32/kW

Residential Technology Costs
Housing
Stock
Rural
Urban
Apartment
New
Existing
Urban – Space Heating 2020 2030
Air Fans €135/kW €135/kW
Natural Gas Condensing Boiler €256/kW €256/kW
Hydrogen Burner €1623/kW €1623/kW
Biomass Stove €92/kW €92/kW
Urban – Water Heating 2020 2030
Oil Boiler €161/kW €161/kW
Wood-pellet Boiler €300/kW €300/kW
Solar Collector with electric backup €782/kW €782/kW
Urban - Appliances 2020 - Standard
2020 - High
Efficiency
Combined Washing/Dryer Machine €0.55/kW €0.72/kW
Fridge/Freezers €0.75/kW €1.60/kW
Dishwashers €0.15/kW €0.32/kW

Residential Technology Costs
Housing
Stock
Rural
Urban
Apartment
New
Existing
Rural – Space Heating 2020 2030
Wood Fireplace €165/kW €165/kW
Oil Stove €131/kW €131/kW
Electric Radiators €195/kW €195/kW
Ground Heat Pump with Electric Boiler €1350/kW €1350/kW
Rural – Water Heating 2020 2030
Condensing Oil Boiler €279/kW €256/kW
Biodiesel Boiler €171/kW €171/kW
Solar Collector with Diesel Backup €1424/kW €1424/kW
Rural - Appliances 2020 - Standard
2020 - High
Efficiency
Combined Washing/Dryer Machine €0.55/kW €0.72/kW
Fridge/Freezers €0.75/kW €1.60/kW
Dishwashers €0.15/kW €0.32/kW

Transport Technology Costs
Vehicle
Type
Truck
Bus
Car
New
Cars 2020 2050
Biodiesel €9,700/Vehicle €10,700
Diesel €8,500 €8,500
Petrol - Hybrid €17,000 €11,500
Petrol €8,500 €9,500
LPG €9,500 €10,500
Electric €20,700 €10,000

Transport Technology Costs
Vehicle
Type
Truck
Bus
Car
New
Intercity Bus 2020 2050
Diesel €210,000/Vehicle €211,000
Biodiesel €210,000 €211,000
Natural Gas €235,000 €217,500
Hydrogen Fuel Cell N/A €261,000
Urban Bus 2020 2050
Diesel €210,000 €211,000
Biodiesel €210,000 €211,000
Natural Gas €235,000 €217,500
Hydrogen Fuel Cell N/A €261,000

Transport Technology Costs
Vehicle
Type
Truck
Bus
Car
New
Heavy Duty Truck 2020 2050
Diesel €125,000/Vehicle €126,000
Diesel - Hybrid €130,000 €131,000
Natural Gas €145,380 €146,380
Hydrogen N/A €176,000
Methanol €127,000 €128,000