Carbon Accounting

Carbon Accounting is an initiative to calculate the impact on greenhouse gas emissions produced by business activity. Mizuho has developed its own carbon accounting methodology to calculate the impact on CO2 emissions related to large–scale power generation projects financed by Mizuho (the current methodology has been applied since FY2017). Specifically, the proportion of Mizuho loans in the entire project cost is multiplied by total CO2 emissions and the amount of CO2 emissions reduced—the resulting calculations are our "Contribution to CO2 emissions" and "Contribution to CO2 emission reduction," respectively. The carbon accounting results have been announced in the Mizuho Financial Group official website since FY2006. The accumulated calculation results are used as the future management information for creating a decarbonized society.

Carbon accounting overview

Applicable projects

Each fiscal year, we apply our carbon accounting to new large–scale power generation projects for which financial agreements were signed in that year. This is because power generation plants typically emit substantial amounts of CO2 and these emissions can be calculated relatively easily based on the types of fuels and the annual energy production volumes generated by such facilities.

CO2 emissions

We compile a set of data detailing the CO2 emissions of each power project. CO2 emissions from power generation projects utilizing renewable energy sources are estimated as zero, in principle.

However, greenhouse gases released from steam production in geothermal power generation and from combustion of fuel additives in biomass power generation are included in the emissions data on a CO2–equivalent basis.

CO2 emission reductions

Reduction in CO2 emissions is calculated by using the "Average for All Power Sources" data per country, as listed in the Appendix "Emission Factors for Electricity" of the J–MRV Guidelines published by the Japan Bank for International Cooperation (JBIC). For example, the average CO2 emitted by the power plants in a certain country is considered as a base line. The difference of CO2 emissions between the project and the base line is counted as "reduction". Mizuho calculates the "reduction" achieved by renewable energy projects.

Mizuho Bank's contribution to CO2 emissions and CO2 emission reductions

Our contribution ratio (c)% is the ratio of the financing amount we provide to a project's total cost.

"Contribution to CO2 Emissions" and "Contribution to CO2 Emission Reductions" are defined as the project's CO2 emissions and CO2 emission reductions as described above, multiplied by our contribution ratio for a project. For example, if a natural gas–fired power plant project generates CO2 emissions of [a] tons and Mizuho Bank's contribution ratio is (c)%, then our contribution to CO2 emissions in tons would be [a] multiplied by (c)%. If a wind power project contributes CO2 emission reductions of [b] tons, our contribution to CO2 emission reductions in tons would be [b] multiplied by (c)%.

Result of evaluations

Contributions to CO2 emissions and CO2 emission reductions for power generation projects subject to carbon accounting

(Unit: kiloton of CO2)
FY 2015 2016 2017 2018 2019
Contribution to CO2 emissions 1,136 4,132 1,559 2,807 2,679
Contribution to CO2 emission reductions 465 687 743 1,394 1,459

Note: Prior to fiscal 2016, greenhouse gas emissions from geothermal power facilities were not included in CO2 emissions and CO2 emission reductions calculations, and Contribution to CO2 Emission Reductions was calculated using a baseline of assumed CO2 emissions by a coal–fired power generation plant.

Number of projects by types of fuel subject to carbon accounting

(Unit: Number of projects)
FY 2015 2016 2017 2018 2019
Renewable energy power plant projects Wind 5 5 2 6 10
Solar 16 14 8 1 4
Hydro 0 0 0 0 0
Geothermal 0 1 1 0 0
Biomass 0 0 0 3 2
Fossil fuel–fired power plant projects Coal 1 6 2 3 2
Oil 0 0 0 0 0
Natural gas 7 4 1 3 4
Total 29 30 14 16 22
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