Green Britannia? Some Basic Facts About the UK's Decarbonisation Journey

Abstract

In this brief essay, we trace, at a very high level, the United Kingdom's recent decarbonisation journey, and chart the country's successes and failures in broad strokes. As a country that has made decarbonisation a central feature of its global soft power diplomacy, its experience offers many interesting insights into the limits of political commitment in the presence of techno-economic hurdles. We also look at "discontinuities" in its mid-term decarbonisation curve that might significantly alter its transitional trajectory. Policymakers in countries at different stages of their green transition shift, and notwithstanding current political commitment levels, may still learn a thing or two by tracking developments in jurisdictions perceived to be on the green-shift cutting-edge and approaching their decarbonisation frontiers.

Full text

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Green Britannia?
Some Basic Facts About the UK’s Decarbonisation Journey
Bright Simons
Introduction: The Electricity Success Story
A post-carbon Britain is being held back by stubborn emissions from the transport
and heating sectors (cf. Pollitt & Chyong, 2021; Chaudry et al, 2022).
The persistence of high emissions in these sectors contrasts vividly with the positive
decarbonisation trend in the electricity generation sector over the past three decades
(Walk & Stognief, 2022). And also with the reputation of the UK decarbonisation
pathway as meeting “the Paris Agreement stipulation of ‘highest possible ambition’”
(Climate Change Committee, 2020).
Electricity decarbonisation is as much a function of consumption stabilisation as it is
of greener production. UK annual electricity demand growth averaged 2.4% between
1970 and 2005 hitting a peak in the latter year of 357 TWh (Jamasb & Pollitt, 2011).
Consumption declined to 294 TWh in 2020, roughly the same level as 1993. In
parallel, the use of the dirtiest fuel, coal, has seen a consistent downward trajectory
from 70% in 1990, to 43% in 2012, to 20% in 2015, and to just 1.5% in the generation
mix in 2022 (National Grid ESO, 2022). Total phase-out is scheduled for October
2024.
Ever more efficient appliances; the boost in renewables from under 20% of the
generation mix in 2010 to more than 50% in many months in 2022 (National Grid
ESO, 2022); GDP recomposition away from carbon-intensive sectors; and enhanced
grid techniques have all had a role in the electricity sector’s success story.
The fall of carbon dioxide -equivalent emissions (CO2e) from electricity consequently
accounts for the bulk of the UK’s emissions reduction track record. CO2 emissions
from power plants fell by 63% between 1990 and 2021 (compared to an economy-
wide drop of 38%). In unit terms, this represents a decline in the carbon intensity of
power production from 718 gCO2eq/kWh in 1990 to 193 gCO2eq/kWh in 2022 (BEIS,
2022). The 2030 target of 45 gCO2eq/kWh set by the UK Climate Change Committee
(CCC, 2020) is thus achievable based on the growth rate trendline of, especially, wind
and also solar.
Electricity however accounts for only 26% of UK emissions. As emissions from that
sector have declined, the relative contribution of the stubborn sectors has risen.
Transport, for instance, now accounts for 34%, up from 21% just ten years ago. The
heating sector accounts for another 37% (19% attributable to the residential

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component alone) and in the last two decades its absolute emissions have barely
budged.
For the UK to meet its goal of lowering economy-wide carbon emissions from the
current level of ~341.5 million tons of CO2 per annum (or 424.5 million tons of CO2
equivalent greenhouse gases) in 2022 (BEIS, 2021) to the CCC target of 256 million
tons of CO2 (or 316 million tons of CO2 equivalent greenhouse gases), that is 68%
below the 1990 baseline, by 2030 (CCC, 2020), the decarbonization trendline of
transport and heating must drop significantly.
UK power stations, the decarbonization frontrunners in the electricity sector,
currently emit 54 million tons of CO2 per annum. Carbon savings of 20 million tons
per annum should bring that segment smoothly to its 2030 target but will still leave
65 million tons of CO2 of above-target economy-wide emissions that can only be
tackled in the transport and heating sectors. Here is where the prospects dim.
Transport: going nowhere fast
The UK’s installed electricity capacity as of 2022 was 76 gigawatts, of which about 30
gigawatts was from renewable sources (EIA, 2022). Average production of electricity
was 332 TWh per year. The British government’s calculations show that electrifying
the entire UK car fleet will add extra demand of about 30 TWh (CCC, 2021).
Accordingly, the CCC target is to ensure that 97% of all new car sales in the UK are
electric by 2030.
Whilst a 10% expansion of generation and capacity does not sound onerous, there
are many caveats. Leaving aside alternate scenarios by other commentators who
project much larger capacity expansion requirements, there are multiple factors
militating against the transition.
First, massive production hurdles lie ahead for electric vehicles (EV) as the world rubs
against reserve limits of the rare earth metals needed for their manufacture. Analysts
project total cobalt production to rise only by 60% from 2025 through to 2030
(Stratas, 2021). Such projections of production output of cobalt, nickel, lithium and
other green materials based on rigorous scenario modelling place an upper limit on
EV production growth. It bears noting that today, EVs constitute just 1% to 1.5% of
the UK vehicle fleet. To meet the CCC target, 23 million more EVs are needed, up
from today’s 400,000. (Willis, 2021).
Second, public charging points will have to increase from 18000 to more than
325,000 (Willis, 2021). Again, it bears noting that 30% of all EVs today are in London
and the Southeast, and poorer parts of Britain have very low density of both charging
points and EVs (as a share of local fleets). Most current EV owners have garages or
driveway parking that permit home charging, hence 80% of EV charging sessions

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happen at home. Which is reasonable given the long hours needed to charge, even
with a fast-charging outlet. However, 34% of UK car owners park on the street and
would thus need to use public charging stations rather than home-ports (Willis,
2021).
But even fast-charging points do not begin to offset the massive energy density gap
between diesel/gasoline and lithium-ion batteries. The ratio is currently 40:1 in favour
of fossil fuel liquids (GWPF, 2020). Charging a 60KWh battery equipped EV requires 8
hours at a 7 KW outlet. For a driver to, instead, spend a more reasonable 30 minutes,
massive reinforcement is required at distribution endpoints to create level 3 and level
4 charging stations. Planning permissions to deploy a new commercial outlet alone
can take up to 20 months to navigate in parts of the UK (cf. OfGEM, 2020). Billions of
pounds would be required for the various components of an infrastructure rollout to
make level 3 and 4 outlets ubiquitous (cf. Conzade et al, 2022).
Furthermore, current costs of £33 per 80% charge means that, with time losses
added, EVs are more expensive to fuel, further limiting their use to the middle and
upper classes (cf. Chen et al, 2020).
The slow pace of investments towards addressing these issues accounts for the slow
electrification of transport, resulting in 99% of all transport miles in the UK being
fossil-fueled (Hobley, 2019). But even should things turn around and investments
flood into charging infrastructure, there is another issue: technical feasibility.
Small cars and vans can carry the 500kg batteries needed to power them, and the
grid, with high reinforcements, can accommodate the 10 KW edge outlets required
for fast-charging. Addressing the requirements of heavy good vehicles (HGVs), ships,
passenger aircraft, excavators, ferries and other such mega-mobility systems, on the
other hand, requires much heftier battery capacity and grid adjustments to a scale
that is presently technically and infrastructurally impractical. Yet, together, these
platforms constitute 35% of transport emissions and are presently 100% fossil-fueled.
Unsurprisingly, the government does not even intend to phase out fossil-fueled
HGVs (19% of transport emissions) by 2030. The current, perhaps unrealistic, timeline
is 2040.
Heating: Hot air is expensive
Similar infrastructural investment and financial burden challenges are holding back
the electrification of heating in homes and workplaces.
Like rapid-charging stations in the transport sector, the object of hope in the heating
electrification race is the “heat pump”. Presently, over 85% of heating needs are met

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by natural gas fuelled boilers, and nearly all the remaining 15% by other fossil fuels
like oil and LPG.
However, natural gas boilers have a carbon intensity of more than 200 gCO2e/KWhth
whilst heat pumps have seen their carbon intensity drop from ~250 gCO2e/KWhth in
1990 to less than 60 gCO2e/KWhth in 2020, with projections for 2030 in the range of
16 gCO2e/KWhth.
A mass switchover to heat pumps however faces considerable hurdles. First, there is
the issue of increased load on the grid. Analysts believe that renewables will have to
grow from current output of 122 TWh to ~230 TWh in order to handle the additional
electricity demand. Adding the transport electrification burden creates a massive
energy gap of at least 30 TWh in the most optimistic green power scenarios for 2030.
Furthermore, peak load optimisation presents massive challenges due to the tension
between demand variance and renewable power intermittency. At any rate, the
investment outlay is currently not projected for this level of renewable generation
expansion and grid modification (cf. Aunedi et al, 2022).
Changing investment projections to eliminate generation gaps and grid stress-points
do not however remove all barriers. According to experts, 37% to 54% of UK
properties are not designed to support the insulation prerequisites of heat pumps
(EUA, 2020).
Add to all the above the considerable upfront costs for switching to a ground-source
heat pump. With an average budget requirement of between £13,200 to £27,350, the
average UK household will not break even after 20 years without the government’s
generous Boiler Upgrade Scheme (BUS) subsidy (EUA, 2020). A 20-year break-even
horizon is considerably beyond the tolerance of many UK households. To move from
the current installation rate of 60,000 heat pumps per year to the government’s
preferred rate of 600,000 heat pumps per year, the BUS and other subsidies would
need to be considerably augmented and distributed to hundreds of thousands of
homes. A massive spate of reconstruction would also be needed in older
neighbourhoods to support the insulation prerequisites of heating electrification.
The decarbonization fiscal gap computed from the above scenarios exceeds £210
billion in capex and annual subsidy spending of more than £100 billion. A finding in
stark contrast to the assertion by the CCC that decarbonisation can happen with
minimal public investment and at a cost of just 1% of GDP over the horizon (i.e. £30
billion - £40 billion) (cf. McKay, 2009).
It is not surprising then, considering all these factors, that the UK heat pump
installation rate is the lowest in Europe currently (Rosenow, 2023).
Conclusion: Policy Recommendations

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It is evident from all the foregoing that transport and heating decarbonisation by
2030 within persistent baseline scenarios is impossible. Even preserving current
positive trends would require additional policy optimisation. We present some ideas
in that respect in table 1.
Any futuristic analysis of a policy matter would be incomplete without some due
consideration of extreme scenarios. For this topic, we are interested in optimistic
scenarios that might overturn the conclusions drawn so far and result in the heating
and transport decarbonisation effort actually succeeding by 2030. We classify these
alternate scenarios as the product of “discontinuities in the decarbonisation curve”.
Based on an analysis of 32 such potential discontinuities, we present a prioritisation
matrix in table 2 of the top seven (cf. Dixon et al, 2021; cf. Chaudry et al, 2015).
Table 1
Baseline Decarbonisation Scenario Optimisation
Policy Choice
Median
Cost
Projection1
Decarbonisation
Efficiency
Risk to
Upside
Enhanced Carbon Taxes:
The UK levies implicit carbon taxes on petroleum products but there
is no explicit linkage to emission-intensity in priority industries.
Moving the effective average carbon tax rate from £2.11/tCO2e
(OECD, 2022) to £50 will achieve mitigation-equivalence pricing.
+£45 billion
45% of above target
emissions
Change in
elasticities
over time.
Enhanced Carbon Cap & Trade:
At £70 per tonne, UK carbon prices are within the range needed for
Paris Agreement compliance. Only the EU and New Zealand have
similar prices. However, retirement of UK credits are stuck at less
than 1% of issuance, which itself at 6 million credits remain far below
the level needed to affect emission targets. Extending the woodland
and peat carbon sink schemes is critical to improving the coverage of
the UK ETS.
+£5 billion
10%
Carbon sinks
are not a
renewable
supply.
Luxury Taxes on SUVs:
SUVs emit more than 25% more carbon than saloons. From 7% of
cars sold in 2009, SUVs now account for 40% of new sales.
+5 billion
2.5%
Limited
Suppress Methane Generation:
Of the “Kyoto basket” of gases, methane is the most climate-
important after CO2. 1 kg of Methane = ~28 kgs of CO2e. Methane
accounts for 15% of UK CO2e emissions. Shifting 80% of organic
waste to anaerobic digesters, away from landfills, will greatly impact
methane emissions.
-£1.2 billion
10%
£75.7/tCO2e
Municipal
waste
capacity may
falter.
Next Generation Carbon Capture & Storage:
Carbon dioxide captured and reused in various industrial processes
rather than stored in notionally leak-proof containers could improve
the economics of CCS, which is highly scale-variant.
-£20 billion
(Velev, 2023)
15%
~£800/tCO2e
Demand
estimation
may be
exaggerated.
1To the Treasury

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Table 2
Prioritisation Index for Discontinuities in the Decarbonisation Curve
Impact
Rank
Discontinuity
Probability
Weighting
Emissions
abatement
factor
Economic
Feasibility
1
Biomethane Gas Grids & hydrogen heat pumps:
Methane produced in green digesters or from emission-free gas-stripping
methods can be transported through the existing infrastructure and used
to fuel existing equipment (Dodds & Demoullin, 2013).
75%
25%
Moderate
2
Decarbonised fuel imports:
The UK imported 62% of its natural gas & 50% of liquid fuels in 2022 and
will import 70% in 2030. (Thomas et al, 2022). Based on the UK’s CBAM
policies, negative embodied emissions rated fuel from sources with strong
comparative advantages of CCS and other decarbonisation models, like
Norway, could ensure that heating and transport emissions are offset at
the point of use (Daggash et al, 2019; cf. Jankovic, 2022).
40%
22.5%
Moderate
3
Hydrogen Fuel Blends:
UK gas networks are building capacity in 2023 to ensure 20% hydrogen
blending. Syngas distribution enhancements and reconstituted liquid
hydrocarbons could reach car fuelling stations in greater volumes. Aviation
and marine fuels could receive similar treatment.
(Fantuzzi et al, 2023; cf. Aunedi et al, 2022; Melaina et al, 2013)
65%
12.5%
Moderate
4
Microreactors (“nuclear batteries”):
Microreactors are not “small nuclear reactors” so most of the usual cost
curves based on “linearly downscaling” large nuclear reactor costs do not
apply. Built entirely in factory settings, rigged with failsafes, and rated
between sub-MW to 20MW capacity, they can use low-enrichment
uranium, and those being produced by the likes of Urenco and U-Battery
can generate power at between 14 US cents and 41 US cents per KWh
depending on order volumes. (Black et al, 2023)
25%
15%
Low
5
Digital Twin “Avatars”:
COVID-19 lockdowns resulted in 5% drop in transport emissions but the
corresponding 25% drop in GDP shows that the current elasticity of the
carbon intensity of GDP growth makes forced cuts to transport imprudent
(ONS, 2021). Advanced IoT cum holographic techniques could however
make it possible for far more machinery and other economic systems to
be operated remotely.
20%
15%
Low
6
Superconducting Gridlines:
UK transmission losses increased by 40% between 2013 and 2020
(National Grid, 2020). Adding distribution losses, the total rises to 10% of
total power output. New materials promise lossless power lines. (Thomas,
2016).
25%
7.5%
Low
7
Fusion:
The EU’s EUROFusion Consortium has met critical milestones in the
Horizon 2020 roadmap for the ITER DEMO effort. In the event of a
breakthrough before 2030, plasma fusion reactors, with four times the
energy density of today’s nuclear fission plants, can be realised.
10%
45%
Low

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Absent such optimisation and discontinuity factors, the UK’s decarbonisation
ambitions for 2030 are at grave risk.
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