What is Japan's pathway to limit global warming to 1.5°C?
Power
Power sector in 2030
Japan’s power system is dominated by coal (33%) and natural gas (39%) with 19% coming from renewables and another 9% from nuclear.1 Nuclear energy provided a quarter of power until the Fukushima nuclear accident in 2011. It is slowly increasing again after the 2014 total shutdown, but it is unclear whether it will ever fully regain its former role.2 For much of the last three decades renewable share in power generation remained around 10%, and this was almost entirely due to hydroelectricity. However, beginning in 2012, the country saw an accelerated uptake of solar power.3,4
Paris Agreement compatible pathways show a phase-out of unabated coal by around 2030 and unabated gas between 2038-40. This would primarily be achieved through a significant scale-up of renewable power, which could supply 51-82% of Japan’s power by 2030, and close to 100% in 2050.5 A share of at least 60% would need to be achieved in order to avoid reliance on nuclear energy nor fossil fuels with CCS.6
Japan faces unique challenges in decarbonising its power sector. Historically, the country has opted for nuclear power and energy efficiency measures as a means of meeting increasing demand and maintain security of supply. More recently, demand trends have shifted significantly and, on the supply side, nuclear power’s share in generation dropped after the 2011 Fukushima accident.
Issues with security of supply remain, given the country’s isolated location. While the country has limited potential for solar and onshore wind, offshore wind could provide significant power generating capacity.7 The government has identified offshore wind as a key area of focus in its long-term energy planning. At the same time, Japan also sees nuclear and fossil CCS as important contributors to a future power grid.8,9
Japan's power mix
terawatt-hour per year
In the 100%RE scenario, non-energy fossil fuel demand is not included.
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Graph description
Power energy mix composition in generation (TWh) and capacities (GW) for the years 2030, 2040 and 2050 based on selected IPCC SR1.5 global least costs pathways and a 100% renewable energy pathway. Selected countries include the Stated Policies Scenario from the IEA's World Energy Outlook 2021.
Methodology
Data References
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Towards a fully decarbonised power sector
Under 1.5°C compatible pathways, Japan’s power sector achieves carbon neutrality between 2040 and 2043 by phasing out unabated coal from around 2030 and unabated gas between 2038 and 2040.
Nearly all pathways retain nuclear power in the generation mix.
Some pathways assume a certain level of reliance on carbon dioxide removal. In these pathways fossil fuel generation with CCS commences from the 2030s and accounts for 29-32% of total generation in 2050. In addition to CCS, residual emissions under these pathways are abated with negative emissions technologies, also starting in the 2030s, i.e., bioenergy with CCS which, by 2050, accounts for 1.6-3.2% of total power generation. CCS has yet to been proven an effective means of emissions reduction at scale. Relying on this technology is thus risky.
Japan could achieve a fully decarbonised power system based on renewable energy and storage technologies. The 100% renewable energy pathway modelled here has non-bio renewables share in power generation increasing from 16% (2019 levels) to 81% by 2030 and nearly 100% by 2050.10
In addition to energy efficiency measures, technologies most readily available to Japan to facilitate this transition are solar PV on buildings and offshore wind, paired with geothermal and hydropower.11
Japan's power sector emissions and carbon intensity
MtCO₂/yr
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Graph description
Emissions and carbon intensity of the power sector in selected 1.5°C compatible pathways.
Methodology
Data References
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Investments
Yearly investment requirements in renewable energy
Across the set of 1.5°C pathways that we have analysed, annual investments in renewable energy excluding BECCS increase in Japan to be on the order of USD 22 to 84 billion by 2030 and 20 to 64 billion by 2040 depending on the scenario considered. The ‘high energy demand, low CDR reliance’ pathway shows a particularly high increase in renewable capacity investments, which could be driven by an increase of electrification of end-use sectors. Other modelled pathways have relatively lower investments in renewables and rely to varying degrees on other technologies and measures such as energy efficiency and negative emissions technologies, of which the later can require high up-front investments.
Demand shifting towards the power sector
The 1.5°C compatible pathways analysed here tend to show a strong increase in power generation and installed capacities across time compared with a current policy scenario. This is because end-use sectors (such as transport, buildings or industry) are increasingly electrified under 1.5°C compatible pathways, shifting energy demand to the power sector. Globally, the “high energy demand” entails a particularly high degree of renewable energy-based electrification across the various sectors, and sees a considerable increase in renewable energy capacities over time.
Japan's renewable electricity investments
Billion USD / yr
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Graph description
Annual investments required for variable and conventional renewables installed capacities excluding BECCS across time under 1.5°C compatible pathway.
Methodology
Data References
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1.5°C compatible power sector benchmarks
Carbon intensity, renewable generation share, and fossil fuel generation share from illustrative 1.5°C pathways for Japan
| Indicator |
2019
|
2030
|
2040
|
2050
|
Decarbonised power sector by
|
|---|---|---|---|---|---|
|
Carbon intensity of power
gCO₂/kWh
|
502
|
82 to
82
|
4 to
6
|
-29 to
0
|
2040 to
2043
|
|
Relative to reference year in %
|
-84 to
-84%
|
-99 to
-99%
|
-106 to
-100%
|
| Indicator |
2019
|
2030
|
2040
|
2050
|
Year of phase-out
|
|---|---|---|---|---|---|
|
Share of unabated coal
per cent
|
33
|
4 to
4
|
0 to
0
|
0 to
0
|
|
|
Share of unabated gas
per cent
|
39
|
8 to
11
|
0 to
0
|
0 to
0
|
2038 to
2040
|
|
Share of renewable energy
per cent
|
19
|
51 to
82
|
62 to
93
|
65 to
99
|
|
|
Share of unabated fossil fuel
per cent
|
75
|
14 to
16
|
0 to
1
|
0 to
0
|
BECCS are the only Carbon Dioxide Removal (CDR) technologies considered in these benchmarks
All values are rounded
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Methodology
Data References
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