Climate Change Plan: third report on proposals and policies 2018-2032 – technical annex

Model Development from Draft to Final Climate Change Plan

Overview

There have been three milestone TIMES runs that have informed the development of the final Climate change Plan. This section discusses the main components of each. Further detail is provided in the sector-specific discussion in the following section.

A number of technical changes were made to parameters, as well as changes in the categorisation of variables. As a result, it is not possible to make comparisons across these runs nor isolate the individual impact of each change.

Draft Climate Change Plan

The figure below presents the emissions envelopes from the draft Climate Change Plan.

Figure 5: Sector Envelopes from Draft Climate Change Plan, TIMES model results

September 2017

A number of updates were made to the model between the draft Plan model run and the end of September 2017. Of these, one of the largest changes in terms of impact on results was the update to the Land Use, Land-Use Change and Forestry ( LULUCF) projections. Updated projections were provided by the Department for Business, Energy and Industrial Strategy ( BEIS), which are consistent with those used for their January update to the Updated Energy and Emissions Projections ^[3] . These were produced by the Centre for Ecology and Hydrology ( CEH), and reviewed by BEIS. Net removals from the LULUCF sector are now approximately 6 MtCO ₂e higher per annum, on average, than in the data used for the draft Plan, and the sector now remains a net sink over the timeframe of the Plan.

Alongside this change, Transport emissions were revised exogenously and coded into the model, to take account of the Programme for Government announcement on phasing out the need to buy petrol and diesel engine cars and vans by 2032. The emissions released from the changes to the LULUCF and Transport sectors have resulted in changes to the Residential, Service and Industrial sectors. Electricity emissions in this run are lower in early years, with the envelope increasing in later years, relative to the draft Plan. The Waste envelope and the non-energy component of the Agricultural envelope have both been revised using sector specific analysis, with the new emissions profiles coded into TIMES.

Figure 6: Sector Envelopes from September 2017, TIMES model results

Updates made to the model between the draft Plan and end-September 2017 are summarised as follows:

• In response to the feedback on the draft Climate Change Plan and Energy Strategy, we have revised our assumptions about the application of carbon capture and storage ( CCS). The feedback we received highlighted the challenge of deploying CCS at scale in the period set out in the draft Plan. We have therefore constrained the use of biomethane and other biomass in electricity generation and industrial processes that produce captured emissions over the modelling timeframe, eliminating the model's ability to produce negative emissions. The final Plan, therefore, does not depend on negative emissions
• We added a new minimum constraint for offshore wind electricity generation capacity between 2020 and 2025, reflecting installed and planned capacity. We also added a new floating wind technology that is made available for the model to use, drawing from Scottish-specific project data
• The share of Scottish non-domestic building energy demand as a share of the UK demand was updated to the most recent data available on non-domestic energy consumption share
• We incorporated smart meters into the Residential and Service sectors, with updated energy savings potential drawing on the UK Government cost-benefit analysis of the smart meter roll-out. Smart meters are expected to allow consumers to develop more energy efficient behaviours, leading to reduced energy consumption
• The aviation and shipping emissions cap was modified within the TIMES model, so that it includes all domestic technologies, as some were previously missing from the cap definition (but still being captured elsewhere in the modelling)
• The Transport emissions profile was updated to reflect the impact of the Programme for Government announcement, on phasing out the need to buy petrol and diesel engine cars and vans by 2032
• We incorporated a new emissions profile for Agriculture, derived from the latest Greenhouse Gas Inventory figures. The agricultural transport demand driver was revised, reflecting the downward trend in baseline non-energy emissions
• Tonnages of organic and inorganic municipal solid waste, wet biomass waste, landfill gas, sewage sludge and animal slurry available as resource inputs to the model, have been updated
• We incorporated a new set of baseline LULUCF projections provided and reviewed by BEIS, and produced by the Centre for Ecology and Hydrology ( CEH)
• CO ₂ removals from woodland planting which would have occurred without policy intervention were not included in the new planting figures
• We updated the assumptions regarding the potential availability of future biomass
• We constrained the application of hydrogen with natural gas in the existing gas network over the period of the Climate Change Plan

October 2017

Further updates were applied during October 2017. These are detailed as follows and had the combined impact of adjusting the sector envelopes to those shown in the figure below. The largest impact was on the Electricity sector, where emissions increased in all years and in the Residential and Service sectors, where the envelopes became relatively tighter.

Figure 7: Sector Envelopes from October 2017, TIMES model results

Further constraints added between September and October 2017 were as follows:

• The model was updated to reflect the 2015 Greenhouse Gas Inventory (published in 2017)
• In response to the feedback on the draft Climate Change Plan and Energy Strategy, we have delayed the use of CCS in electricity until after 2030
• We have updated the constraint on exports/imports of electricity to ensure the system maintains sufficient capacity to continue exporting to the rest of the UK, and that Scottish climate targets are not met by exporting emissions to other parts of the GB system
• We have conducted an update of the historical generation, capacity and load factor data inputs in the electricity sector in Scottish TIMES, drawing from BEIS Energy Trends December 2016, DUKES 2016, BEIS Renewable electricity capacity and generation (2017), BEIS Regional Statistics - 2003 - 2015: Standard Load Factors, the Renewable Energy Planning Database (2017), and from an updated version of UK TIMES
• We updated the energy saving potential and cost of phased conservation measures in the Residential sector, which included expanding the set of conservation measures modelled, drawing on data from the National Household Model. We also updated the energy saving potential of phased conservation measures in the Service sector
• We have constrained the potential deployment of district heating to align with figures in the UK's National Comprehensive Assessment of District Heating and Cooling (2015)
• Base year average space heat and hot water demand in the Residential sector was calibrated to account for differences between modelled and actual data, based on data from the UK TIMES model. New build average space heat and hot water demand is based on the (now calibrated) base year demand
• We have now defined an increasing share of heat and hot water demand in the Residential sector that must be met by low-carbon technologies and fuels (including electricity) over time. The share of heat and hot water demand that must be met by low-carbon technologies and fuels in the final Plan is limited to broadly align with the proportion of properties that are not on the gas grid and advice from the Committee on Climate Change ( CCC)
• The Transport emissions profile was rebased to reflect the impact of the 2015 Greenhouse Gas Inventory

Final Climate Change Plan

Updates

There were a number of small changes introduced to the model between the October 2017 run and the final run to take into account some technical adjustments:

• The cumulative emissions shortfall on targets in previous years that has been accounted for in the current Plan has been updated to reflect the latest Greenhouse Gas Inventory
• We resolved a technical issue where commodities continued to be imported and not used by the Electricity sector. This has no impact on emissions, as the commodities are not transformed

Overall, these have led to a minor reduction to the Electricity and Industrial emissions envelopes in later years.

Figure 8: Sector Envelopes in final Climate Change Plan

The table below sets out the final Climate Change Plan sector envelopes.

Table 1: Sector Envelopes in final Climate Change Plan

Climate Change Plan - Sector Annual Envelopes ( MtCO2e)

	2018	2019	2020	2021	2022	2023	2024	2025	2026	2027	2028	2029	2030	2301	2032
Agriculture	8.4	8.4	8.4	8.3	8.2	8.1	8.0	8.0	7.8	7.6	7.7	7.7	7.7	7.6	7.6
Electricity	2.7	2.6	2.5	2.5	2.5	2.5	2.6	2.6	2.5	2.3	2.2	2.2	2.1	2.0	2.0
Waste	1.2	1.2	1.1	1.0	1.0	0.9	0.9	0.8	0.8	0.7	0.7	0.7	0.6	0.6	0.6
Industry	10.3	10.2	10.0	9.8	9.7	9.5	9.4	9.2	8.9	8.6	8.4	8.3	8.2	8.2	8.1
Residential	6.1	6.1	6.1	6.1	6.0	6.0	5.9	5.8	5.6	5.4	5.3	5.2	5.1	4.9	4.7
Services	2.9	2.8	2.6	2.6	2.5	2.5	2.5	2.5	2.2	2.0	1.8	1.6	1.4	1.4	1.4
Transport	12.8	12.6	12.4	12.1	11.8	11.5	11.1	10.7	10.4	10.0	9.6	9.2	8.8	8.4	8.1
LULUCF	-5.3	-6.1	-6.9	-6.9	-6.8	-6.7	-6.6	-6.6	-6.6	-6.5	-6.5	-6.5	-6.5	-6.6	-6.7