Carbon Neutral City
achieved by Next-generation Photovoltaics

Innovation for Cool Earth Forum（ICEF） 2023
NEDO Green Innovation Fund Projects Symposium
4 October 2023
Yukari TAKAMURA (The University of Tokyo)
e-mail: yukari.takamura@ifi.u-tokyo.ac.jp
1

Toward climate neutrality
Paris Agreement（2015）stipulating clear long-term goal for decarbonization• Holding the increase in the global average temperature to well below 2 ℃ and pursuing efforts to limit thetemperature increase to 1.5 ℃ above pre-industrial levels (Art. 2.1 (a))• “Net zero emission” “De-carbonization” in the second half of this century (Art. 4.1)

Japan's pledge: reduce GHG emission to net zero by 2050
• “Japan pledges to, by 2050, reduce GHG emission in Japan to net zero, namely become carbon neutral and achieve adecarbonized society”.
• The pledge is now legalized under the 1998 Law to promote measures to cope with global warming.

More than 150 countries and EU have now pledge to reduce emission to net zero
• All G7 countries, Brazil, South Korea, Viet Nam etc.: net zero by 2050 at the latest• China, Russia, Saudi Arabia etc.: net zero by 2060 at the latest• India: net zero by 2070
• Many countries update their 2030 climate target upward in line with net zero by 2050.

COP26："resolves to pursue efforts to limit the temperature increase to 1.5 °C"• "recognizes that this requires accelerated action in this critical decade, on the basis of the best available scientificknowledge and equity"• Repeated endorsement by COP27, G7, G202

2019 Top 10 Global Economic Loss Events
Date (s)EventLocation

DeathsEconomic Loss（USD billions）

Insured Loss（USD billions）

October 6-12

Typhoon Hagibis (No.
19)

Japan9915.0

9.0

June - August

Monsoon Floods

September 7-9

Typhoon Faxai（No. 15）

May - July

Mississippi Basin Floods

China
Japan
United States

August 25 –Sep 7

Hurricane Dorian

Bahamas,Caribbean, US,
Canada

300
3083

15.0
10.0
10.0
10.0

0.7
6.0
4.0
3.5

March 12-31

Missouri Basin Floods

June - OctoberMonsoon Floods

United States
India

August 6-13

Typhoon Lekima

China,
Philippines,Japan

101750
101

10.0
10.0
9.5

2.5
0.2
0.8

March - April

Flooding

Iran778.3

0.2May 2-5

Cyclone FaniIndia,
Bangladesh

81

8.1

0.5

All Other Events

126 billion

44 billion

Totals232 billion

71 billion

Source：AON, 20203

2022 Top 10 Human fatality events
DeathsEconomic loss（$ billion）

10-20 July

Heatwave

Western, Southernand Central Europe

15450

N/A

13 – 19 June

Heatwave

Western, Southernand Central Europe

3750

N/A

17 May -31 October

India Seasonal Floods

India

2135

4.2

14 June -30 October Pakistan Seasonal
FloodsPakistan

1739

15.0

22 JuneEarthquake

Afghanistan, Pakistan

1163

0.1

1 July -31 October

Nigeria Seasonal Floods

Nigeria660

2.3

21 November

Cianjur Earthquakes

Indonesia

603

0.4

8 -15 April

KwaZulu-Natal Floods

South Africa

455

3.6

15-16 February

Rio de Janeiro Floods

Brazil232＜0.18-13 April

Tropical Storm Megi

Philippines

214＜0.14900

287.0

31300

313 billion

All other events

Totals

Source：AON, 2023

4

Projected changes in extremes are larger
in frequency and intensity
1850-1900

Present 1℃

1.5℃

2℃

4℃

Hot
temperature
extremes overland: 10-year
event

Intensity
increase

1.2℃ hotter

1.9℃ hotter

2.6℃ hotter

5.1℃ hotter

Frequency
per 10 years

2.8 times

4.1 times

5.6 times

9.4 times

Hottemperature
extremes overland: 50-yearevent

Intensity
increase

1.2℃ hotter

2.0℃ hotter

2.7℃ hotter

5.3℃ hotter

Frequency
per 50 years

4.8 times

8.6 times

13.9 times

39.2 times

Heavy
precipitation
over land: 10year event

Intensity
increase

6.7％ wetter

10.5％ wetter

14.0％ wetter

30.2％ wetter

Frequency
per 10 years

1.3 times

1.5 times

1.7 times

2.7 times

Agricultural &ecologicaldroughts indrying
regions: 10year event

Frequency
per 10 years

1.7 times

2.0 times

2.4 times

4.1times

Source: IPCC AR6, 2021
5

The most recent science tells us
IPCC Sixth Assessment Report Synthesis Report（March 2023）•

Critical decade/decisive decade– Climate change as imminent risk. Global climate related economic loss has inreased.
– Every increment of global warming will intensify multiple and concurrent hazards. "Limits toadaptation"– 1.5℃ and 2℃ goals involve rapid and deep, immediate GHG emissions reductions in all sectors
this decade. Global net zero CO2 emissions are reached in the early 2050s, and around the early2070s, respectively.

Reduction rate compared to emissions in 2019
2030

2035

2040

2050

1.5℃ goal GHG（>50%）CO2

43 [34 - 60]

60 [49 - 77]

69 [58 - 90]

84 [73 - 98]

48 [36 - 69]

65 [50 - 96]

80 [61 - 109]

99 [79 - 119]GHG

21 [1 - 42]

35 [22 - 55]

46 [34 - 63]

64 [53 - 77]

CO2

22 [1 - 44]

37 [21 - 59]

51 [36 - 70]

73 [55 - 90]

2℃ goal（>67%）• From goals and policies to implementation and actions• Extension of our present society will not lead to a sustainable society in future.
= need "systems transitions"
Source：IPCC, 2023, modified by Takamura
6

Gap between pathways toward 1.5℃ goaland 2030 NDCs
Extension of our present society will not lead to a sustainable society in future.
= need "systems transitions"
Clear long term vision/goal for future society makes us identify and understand challenges.
Progress in 2030 NDCs
in 2016

Gap between 1.5℃ goal pathways and 2030 NDCs

Source：UNFCCC 2023

7

Source：IEA 2022

All of new buildings are zero-carbon ready885% of buildings are zero-carbon readyCost effective mitigation options areavailable
Energy Supply

Infrastructure

Efficient buildings, vehicle,
lighting, appliances, transport
are cost effective options.

Land, Water, Food
Source: IPCC AR6 Synthesis Report、2023

9

Annual new power-generating
capacity additions (global)

Source：BloombergNEF, 2022

10

Global investment in energy transition
Energy transition investment surpassed USD 1 trillion in 2022, which increased by 31%
from 2021.
Become triple from 2015, 35 times increase from 2004.
11出典: BloombergNEF, 2023

CO2 emissions from energy combustion and industrial process
and change compared to the previous year（1900 – 2022）
Emissions in 2020 decreased by more than 5％ compared to in 2019.
Emissions in 2021 increased by more than 6％ compared to in 2022.
Emission in 2022 increased by 0.9% (historic record) while global GDP increased by 3.2%.
=decoupling between CO2 emissions and economic growth.

.
Source: IEA 2023

12

Drivers for change in global emissions(2021-2022)
Solar and wind expansion offset increase in emission of power sector.
Without expansion of clean energy technologies, increase in 2022 emissions would have tripled.

.
出典: IEA 2023

13

Key milestones for the electricity sector inthe NZE Scenario, 2022-2050

Source: IEA, 2023

14

Total installed capacity and electricity
generation in the NZE Scenario, 2010-2050

Source: IEA, 2023

15

Perovskite Solar Cells• Remarkable progress in recent years with rapid
increases in efficiency, from about 3% in 2009 to over25%.
• Possiblity of broader application, for instance, in urban
areas, where large scale deployment of conventionalcells could be difficult.
• Challenges（cf. Siegler et al., ACS Energy Lett. 2022）– Stability and durability: limited operational lifetimes.
– improvement in efficiency in medium- and large-area
modules– Scaling up perovskite manufacturing– Validation, performance verification and bankability
16

17

Importance of actions by urban areas（IPCC AR6, 2022）
••

•

•

The global share of emissions that can be attributed to urban areas isincreasing. In 2015, urban emissions were estimated to be 25 GtCO2-eq(about 62% of the global share) and in 2020, 29 GtCO2-eq (67–72% of theglobal share).
Urban areas can create opportunities to increase resource efficiency andsignificantly reduce GHG emissions through the systemic transition ofinfrastructure and urban form through low-emission development
pathways towards net-zero emissions.
Policy packages for buildings which combine ambitious sufficiency,efficiency, and renewable energy measures, are effectively implemented
and barriers to decarbonisation are removed. Well-designed andeffectively implemented mitigation interventions have significant potential
to contribute to achieving SDGs . Benefits of transition: reducing energy
bill, improving health, strengthening resilience…
Cities can achieve net-zero emissions, but only if emissions are reduced
within and outside of their administrative boundaries through supply
chains, which will have beneficial cascading effects across other sectors.
18

Expectations and challengesof the new-generation PV• Role in the emerging new energy system toward decarbonization.
– Towards energy system with more distributed and interlinked energy
sources.
– Energy system integration：How to integrate variable renewable into
the grid? How to ensure and increase flexibility of power system, in a
decarbonized and cost- effective ways?

• Technologies and policy interact: How to promote/acceleratetransition, including development and diffusion of thesetechnologies?
– Policies and measures to raise demand for and to create market oflower carbon products and services. Policies and measures to makecarbon (reduction) value clearly visible to users and consumers– Building infrastructure for new technologies, including institutional
infrastructure enhancing innovation, such as new standards and QC
scheme, regulatory measures– Promoting financial flow and investment for new technologies• Collaboration with a variety of technology areas and disciplines.

19

3D : Decarbonization, Decentralization and Digitalization
Innovation progresses across the sectors (through sector coupling)"Grid integrated efficient buildings" "Grid interactive efficient buildings"
Complementarity of technologies 技術の補完性

Source: IRENA, 201720

Sector CouplingPower to X
Energy System Integration

Source: IRENA, 201821

Thank you for your attention!
Yukari TAKAMURA
E-mail: yukari.takamura@ifi.u-tokyo.ac.jp22