Environmental Load of Business Activities

The depletion of energy resources, global warming, threats to biodiversity and other environmental problems are having an increasingly serious impact on the global environment. Given these situations, the SUMCO Group (Japan) identifies forms of energy such as electric power, chemical substances, waste products, and wastewater as significant environmental aspects in its production activities. And we pursue initiatives to consider the environment and reduce environmental load across all of our business activities.

Business Activities and Environmental Load in 2024 (SUMCO Group [Japan])

Flowchart of SUMCO Group’s domestic business activities and environmental impact for 2024. The diagram shows a flow from Input (Energy, Water, PRTR substances) on the left, to Business Activities (Product Development, Procurement, Manufacturing, Transport) in the center, and Output (GHG emissions, transport CO2 emissions, wastewater, waste, PRTR substances) on the right. Key figures: Electricity consumption 1,599 GWh, GHG emissions 740 kt-CO2e, and total wastewater 16.8 Mm³.

(remark)

Underlined items are subject to third-party verification.
Figures are rounded to the nearest whole number, so the total of the breakdown and the total value shown may differ.
Additionally, data of High-Purity Silicon Corporation has been incorporated since 2024.

List of Boundaries

Site Energy
usage		 GHG
emissions		 Water used/
wastewater		 Industrial waste
generated		 VOC
emissions		 PRTR
emissions		 Atmospheric pollutant
emissions		 Abbreviation
Includes SUMCO Group
companies in Japan		 Kyushu Factory (Nagahama, Imari) ○ ○ ○ ○ ○ ○ ○ SUMCO
Kyushu Factory (Kubara, Imari) ○ ○ ○ ○ ○ ○ ○
Kyushu Factory (Saga) ○ ○ ○ ○ － － ○
Yonezawa Plant ○ ○ ○ ○ ○ ○ －
Chitose Plant ○ ○ ○ ○ － － －
JSQ Division ○ ○ ○ ○ － ○ ○
SUMCO TECHXIV Corp. Nagasaki Plant ○ ○ ○ ○ ○ ○ ○ STC
SUMCO TECHXIV Corp. Miyazaki Plant ○ ○ ○ ○ － ○ ○
SUMCO Technology Corp. Noda Plant ○ ○ ○ ○ － ○ ○ STEC
High-Purity Silicon Corporation ○ ○ ○ ○ ○ ○ ○ HSJ
SUMCO Group
Companies Overseas		 SUMCO Phoenix Corporation ○ ○ ○ ○ － － ○ SPX
PT. SUMCO Indonesia ○ ○ ○ ○ － － ○ SPTI
FORMOSA SUMCO TECHNOLOGY CORPORATION ○ ○ ○ ○ － － ○ FST
High-Purity Silicon America Corporation ○ ○ ○ ○ － － ○ HSA
SUMCO Europe Sales Plc ○ ○ － － － － － SES
SUMCO Singapore Pte.Ltd. ○ ○ － － － － － SSGP
SUMCO Taiwan Technology Corporation ○ ○ － － － － － STWN
  • Including all Japan and overseas sites.
  • Since 2024, High-Purity Silicon Corporation and High-Purity Silicon America Corporation have been included in the boundaries.

Environmental Load (SUMCO Group / domestic)

GHG emissions (domestic) (thousand tons-CO2e per year)

  • Bar graph showing the trend of SUMCO’s GHG emissions (Scope 1+2). Emissions are 434 in 2022, 557 in 2023, and 421 in 2024 (all in thousand t-CO2e/year).
  • Bar graph showing the trend of STC’s GHG emissions (Scope 1+2). Emissions are 120 in 2022, 184 in 2023, and 164 in 2024 (all in thousand t-CO2e/year).
  • Bar graph showing HSJ’s GHG emissions (Scope 1+2). The emission for 2024 is 155 (thousand t-CO2e/year).
  • Bar graph showing the trend of Scope 3 GHG emissions (Domestic). Emissions are 882 in 2022, 1,133 in 2023, and 1,404 in 2024 (all in thousand t-CO2e/year).

Water consumption (domestic) (Mm3 per year)

  • Bar graph showing the trend of SUMCO's water consumption. Figures are 12.6 in 2022, 13.0 in 2023, and 13.4 in 2024 (all in Mm3/year).
  • S Bar graph showing the trend of STC’s water consumption. Figures are 4.8 in 2022, 5.2 in 2023, and 5.5 in 2024 (all in Mm3/year).
  • Bar graph showing HSJ’s water consumption. The figure for 2024 is 1.3 (Mm3/year).

Environmental Load (SUMCO Group / overseas)

Map showing the overseas locations of the SUMCO Group. Four locations are marked: FST in Taiwan (orange), SPTI in Indonesia (blue), and both SPX (gray) and HSA (green) in the United States.

GHG emissions (overseas) (thousand tons-CO2e per year)

  • Bar graph showing the trend of SPTI’s GHG emissions (Scope 1+2). Emissions are 12 in 2022, 11 in 2023, and 11 in 2024 (all in thousand t-CO2e/year).
  • Bar graph showing the trend of FST’s GHG emissions (Scope 1+2). Emissions are 167 in 2022, 171 in 2023, and 290 in 2024 (all in thousand t-CO2e/year).
  • Bar graph showing the trend of SPX’s GHG emissions (Scope 1+2). Emissions are 60 in 2022, 52 in 2023, and 36 in 2024 (all in thousand t-CO2e/year).
  • Bar graph showing the trend of HSA’s GHG emissions(Scope 1+2). Emission is 104 in 2024 (all in thousand t-CO2e/year).

Water consumption (overseas) (Mm3 per year)

  • Bar graph showing the trend of SPTI’s water consumption. Figures are 0.4 in 2022, 0.4 in 2023, and 0.3 in 2024 (all in Mm3/year).
  • Bar graph showing the trend of FST’s water consumption. Figures are 3.0 in 2022, 3.2 in 2023, and 4.0 in 2024 (all in Mm3/year).
  • Bar graph showing the trend of SPX’s water consumption. Figures are 1.5 in 2022, 1.4 in 2023, and 1.4 in 2024 (all in Mm3/year).
  • Bar graph showing HSA’s water consumption. The figure for 2024 is 0.7 (Mm3/year).
  • Since 2024, the GHG emission factors of the overseas affiliates have been based on either local emission factors or the International Energy Agency (IEA) Emission Factors.

Environmental Data (SUMCO Group / domestic and overseas)

GHG Emissions Data

(thousand tons-CO2e per year)

Calculation Method 5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
Scope 1
(Direct)		 Conventional 25 27 28 33 －
SBT-compliant*1 － － － 86 84
Scope 2
(Indirect)		 Conventional 765 812 765 942 －
SBT-compliant*1 － － － 1,194 1,097
Scope 3
(Other)		 Conventional 694 758 882 1,133 －
SBT-compliant*1 － － － 1,769 1,732
Scope 1&2 Conventional 790 839 793 975 －
SBT-compliant*1 － － － 1,280 1,181
Scope 1, 2&3 Conventional 1,484 1,597 1,675 2,109 －
SBT-compliant*1 － － － 3,049 2,914
  • For the 2023 calculation, we have added the SBT-compliant calculation methods. From 2024 onwards, we disclose the results using SBT-compliant calculation methods.

(remark)

Figures are rounded to the nearest whole number, so the total of each Scope and the total value shown may differ.

Greenhouse Gas Emissions Scope3 Data (SUMCO Group / domestic and overseas)

(thousand tons-CO2e per year)

Category 2024
Domestic Overseas
1 Purchased goods and services 696 138
2 Capital goods 290 13
3 Fuel- and energy-related activities not included in Scope 1 or Scope 2 150 65
4 Upstream transportation and distribution 78 21
5 Waste generated in operations 18 1
6 Business travel 5 1
7 Employee commuting 19 5
8 Upstream leased assets Not applicable Not applicable
9*1 Downstream transportation and distribution 2 6
10*1 Processing of sold products 115 61
11 Use of sold products Not applicable Not applicable
12*1 End-of-life treatment of sold products 25 16
13 Downstream leased assets Not applicable Not applicable
14 Franchises Not applicable Not applicable
15*1 Investments 5 0
  • Categories 9,10,12, and 15 were added for SBT certification after 2024.

(remark)

Figures are rounded to the nearest whole number, so the total of the breakdown and the total value shown may differ.

GHG Emissions Data (by Company)

(thousand tons-CO2e per year)

Calculation Method 5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
SUMCO*1 Conventional 1,132 1,228 1,316 1,691 －
SBT-compliant*2 － － － 1,991 1,825
STC Conventional 119 131 120 184 －
SBT-compliant*2 － － － 184 164
HSJ SBT-compliant*2 － － － 153 155
FST Conventional 165 165 167 171 －
SBT-compliant*2 － － － 360 401
SPX Conventional 57 60 60 52 －
SBT-compliant*2 － － － 95 87
SPTI Conventional 12 12 12 11 －
SBT-compliant*2 － － － 34 25
HAS SBT-compliant － － － 230 257
Others*3 SBT-compliant － － － 0.3 0.2
Total Conventional 1,484 1,597 1,675 2,109 －
SBT-compliant*2 － － － 3,049 2,914
  • Domestic Greenhouse Gas Emissions Scope3 is aggregated as "SUMCO".
  • For the 2023 calculation, we have added the SBT-compliant calculation methods. From 2024 onwards, we disclose the results using SBT-compliant calculation methods.
  • Overseas non-manufacturing sites

(remark)

Figures are rounded to the nearest whole number, so the total of the breakdown and the total value shown may differ.

GHG Data (Scope 1) (SUMCO Group / domestic)

(tons)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
CO2 25,000 27,000 28,000 31,000 25,158
CH4 － － － － －
N2O － － － － －
HFC 0.006 0.014 0.014 1.7 1.5
PFC － － － 0.048 0.048
SF6 － － － 0 0.001
NF3 － － － － －
  • Figures are rounded to the nearest whole number, so the total of the breakdown and the total value shown may differ.

Energy Consumption(SUMCO Group / domestic and overseas)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
Electricity usage (GWh) 1,792 1,877 1,963 1,899 2,462
Electricity (converted to petroleum) (kL) 451,085 472,505 494,290 478,178 548,868
Fuel (converted to petroleum) (kL) 8,804 9,670 10,103 10,868 27,872
Steam (converted to petroleum) (kL) － － － 1,561 16,553

Water Supplied (SUMCO Group / domestic and overseas)

(Mm3 per year)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
Surface water (rivers, wetland, natural lakes) 14.8 15.7 17.3 17.9 20.5
Water underground (well water) 3.2 3.5 3.8 4.1 4.4
Quarry water － ― － － －
Potable water 1.1 1.3 1.3 1.2 1.6
External drainage － ― － － －
Rainwater － ― － － －
Seawater － ― － － －
Total 19.1 20.5 22.4 23.2 26.5

Water Supplied (by Company)

(Mm3 per year)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
SUMCO 10.4 11.1 12.7 13.0 13.4
STC 4.2 4.6 4.8 5.2 5.5
HSJ － － － － 1.3
FST 2.8 3.0 3.0 3.2 4.0
SPX 1.3 1.4 1.5 1.4 1.4
SPTI 0.4 0.4 0.4 0.4 0.3
HSA － － － － 0.7
Total 19.1 20.5 22.4 23.2 26.5
  • Please refer the page of "Effective Use of Water Resources" for water-stressed area.

Drainage Water(SUMCO Group / domestic and overseas)

(Mm3 per year)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
Total water drained into the ocean 8.6 9.1 10.3 10.7 11.9
Total water drained to surface water sources － － － － －
Total water drained to underground sources / well water sources － － － － －
Total water drained outside of plants 4.7 4.8 5.1 5.4 5.9
Other drainage water 3.1 3.5 3.5 3.4 3.8
Total drainage water 16.4 17.4 18.9 19.5 21.6

Drainage Water (by Company)

(Mm3 per year)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
SUMCO 8.9 9.6 10.8 10.8 11.1
STC 3.7 4.0 4.2 4.5 4.8
HSJ － － － － 0.8
FST 2.3 2.3 2.3 2.7 3.0
SPX 1.1 1.1 1.2 1.2 1.3
SPTI 0.4 0.4 0.4 0.3 0.3
HSA － － － － 0.3
Total 16.4 17.4 18.9 19.5 21.6

VOC emissions (SUMCO Group / domestic)

(tons per year)

5 years prior
(2020)		 4 years prior
(2021)		 3 years prior
(2022)		 2 years prior
(2023)		 Last year
(2024)
VOC 8.4 11.3 10.3 5.5 4.9
  • Chemical Substances have been tabulated based on the PRTR system of the Ministry of Economy, Trade and Industry since 2021.

CDP

SUMCO has been recognized by the international NGO “CDP*1” for its efforts in climate change and water security, and in 2024, we were included in the CDP's Water A List*2, recognizing us as one of the highest performing companies in the area of water resource management.

2024 CDP Scores

Climate Change : A-

Water Security : A

In 2025, we responded to two questionnaires on climate change and water security. Please refer to the PDF below for each answer from SUMCO.

CDP Corporate Questionnaire 2025 (PDF)( 1,553KB)
  • An international NGO that works in the environmental field. They send environmental questionnaires to companies and compile the results and analyze and evaluate them on a common scale.
  • The rating system is a 5-rank scale (A, A-, B, B-, C, C-, D, D-, F). The A List is made up of the companies awarded the highest performance rank of "A".

Third Party Verification of GHG Emissions (SUMCO Group / domestic)

We have conducted third-party verification in accordance with ISO14064-3 for Scope 1, 2, and 3 (Categories 1, 2, and 3) to improve the reliability of the calculation results for GHG emissions of the SUMCO Group (Japan), and obtained a verification report.

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Sustainability

Executive Officer Message Materiality (Key Issues) The SUMCO Group's Business Activities and the Sustainable Development Goals (SDGs) Related Policies CSR and Sustainability Promotion Structure SUMCO Vision Site Data Environmental Social Governance To ESG-oriented Investors Disclosure Based on TCFD Recommendations Sustainability Report / CSR Report