Carbon Dioxide Emissions Reduction Potential in Japan’s Power Sector

The report evaluates a 'Power Switch' scenario for Japan's power sector, which emphasizes renewable energy, natural gas substitution for coal, energy efficiency, and a gradual nuclear phase-out. Compared to a Business As Usual (BAU) scenario, the Power Switch approach could reduce 2020 GHG emissions by 31%, avoiding nearly 2.0 billion tonnes of CO2 equivalent between 2000 and 2020. The net cost of this transition is estimated at 1.1 trillion yen over the period, or 850 JPY per tonne of CO2 equivalent, largely offset by reduced fuel import costs.

• The 'Power Switch' (PS) scenario achieves a 31 percent reduction in annual greenhouse gas (GHG) emissions relative to the 'Business As Usual' (BAU) scenario by 2020, and a 20 percent reduction relative to year 2000 emissions.
• Between 2000 and 2020, the PS scenario would reduce Japan's GHG emissions by 94 million tonnes of CO2 equivalent per year by 2010 and 190 million tonnes per year by 2020, totaling nearly 2.0 billion tonnes of CO2 equivalent over the two decades.
• The net cost of implementing the PS scenario from 2000 to 2020 is approximately 1.1 trillion yen, which equates to about 57 billion yen per year or 850 JPY per tonne of CO2 equivalent.
• The PS scenario's costs are balanced by significant savings: while demand-sector energy efficiency and distributed generation increase costs by nearly 20 trillion yen, these are offset by 14 trillion yen in power sector capital and operating cost reductions and 4.4 trillion yen in fuel import savings.
• The PS scenario proposes a shift in the energy mix by retiring 24 GW of coal-fired capacity by 2020, implementing a gradual nuclear phase-out (retiring 10 GW of capacity by 2020), and increasing the share of renewables to 18.9 percent of total electricity output by 2020.
• Demand-side energy efficiency and distributed generation are critical to the PS scenario, estimated to reduce electricity demand by 114 TWh by 2010 and 238 TWh by 2020.
• The PS scenario improves Japan's energy security and fuel diversity by reducing coal imports by nearly 70 percent and nuclear fuel imports by 20 percent relative to the BAU scenario by 2020.
• The BAU scenario projects that electricity consumption will grow from 968 TWh in 2000 to 1168 TWh in 2020, with GHG emissions from the electricity sector increasing by 21 percent from 2000 levels to 480 million tonnes of CO2 by 2020.

APA

Nakata, M., Oda, J., Heaps, C., & Von Hippel, D. (2003). Carbon Dioxide Emissions Reduction Potential in Japan’s Power Sector. Stockholm Environment Institute. https://cdn.leap.sei.org/documents/PowerSwitchJapan.pdf

Chicago

Nakata, Masami, Junichiro Oda, Charles Heaps, and David Von Hippel. Carbon Dioxide Emissions Reduction Potential in Japan’s Power Sector. Stockholm Environment Institute, 2003. https://cdn.leap.sei.org/documents/PowerSwitchJapan.pdf.

Wikipedia

{{cite report |last1=Nakata |first1=Masami |last2=Oda |first2=Junichiro |last3=Heaps |first3=Charles |last4=Von Hippel |first4=David |title=Carbon Dioxide Emissions Reduction Potential in Japan’s Power Sector |publisher=Stockholm Environment Institute |date=October 2003 |url=https://cdn.leap.sei.org/documents/PowerSwitchJapan.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{nakata2003carbon, author = {Nakata, Masami and Oda, Junichiro and Heaps, Charles and Von Hippel, David}, title = {{Carbon Dioxide Emissions Reduction Potential in Japan’s Power Sector}}, institution = {Stockholm Environment Institute}, year = {2003}, month = oct, url = {https://cdn.leap.sei.org/documents/PowerSwitchJapan.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }