Conserving Water

Due to the rising population and increased living standards driven by economic growth, global demand for water will increase further in the future, and the risk of depletion of water resources has become apparent. On the other hand, the semiconductor manufacturing process requires a large amount of water, and the depletion of water resources could lead to stagnant production as well as impact the procurement of raw materials. Renesas also uses ultrapure water refined from industrial water and other sources, particularly at manufacturing sites, for a variety of applications including cleaning semiconductor wafers and cooling of equipment. We believe that it is essential to secure a sufficient amount of water (fresh water) to maintain stable operations. In case the water supply in the supply chain is disrupted, there is a risk that the purchase of materials for manufacturing semiconductors will be delayed, resulting in delays in production and the delivery of our products to our customers.

Renesas recognizes that water resource conservation is both a global issue and essential for stable operations. We regularly monitor information on water intake and usage by water source and wastewater volumes by discharge destination at all of our manufacturing sites, and manage the quality of wastewater in compliance with local and administrative laws and regulations. In addition, we are striving to improve the recycling rate and efficient use of water, and the entire group is working to improve the total amount of water used per revenue.

At manufacturing sites located in areas where water risks are expected, we continue to make efforts to minimize the impact on the ecosystem of the region by setting and implementing improvement targets for water use per production related revenue.

In addition, as a forest protection activity that nurtures water resources and conserves biodiversity, we also plant trees and contribute to the creation of forests that protect water resources.

Water Resources Conservation Policy and Goals

Renesas has set three policies and targets for water resource conservation.


  1. Improving water utilization efficiency as a means to protect water resources globally
  2. Expand the recycling rate for efficient use of water
  3. Promote water resource conservation in areas with high water risks (areas where sufficient water supply is at risk in the neighborhood.)


Improvement on Total Amount of Water Per Revenue
  1. Improve the water utilization efficiency of the Renesas Group by 33% (basic unit improvement, 2030 target, based on the 2021 level).
  2. For efficient use of water, we will start on-site verification to increase the recycling rate at the Naka Plant to 30%, with a goal of 35% recycling rate (2025 target).
  3. Set improvement targets for water use per production related revenue (based on shipment value) at manufacturing sites with high water risks and strive to conserve water resources.


Renesas recognizes water resource conservation as one of the key strategic aspects of its business strategy. Therefore, CEO is responsible for all activities related to water resource conservation. Policies, important matters, and opportunities and risks related to water resource conservation are regularly discussed and reviewed by the CEO, executive officers appointed by the CEO, and the Sustainability Promotion Office, and regularly reported to the Board of Directors.

Click here for our Sustainability Promotion Structure
Click here for our Environmental Management System

Efficient Use of Water

Renesas aims to reduce consumption by improving manufacturing efficiency and conserving water. At the same time, we actively recycle and utilize recycled water to improve the entire Group’s total amount of water used per revenue.

In 2021, due to the increase in production base operation driven by the strong demand for semiconductors, we decided to reduce the amount of water intake to 16,121 Km3, an increase of 3.8% from the previous year. The recycling rate has decreased by approximately 2%, due to the closure of production bases with a high recycling rate. The total amount water used was 24,867 Km3, an increase by 1.6% compared to the previous year. In addition, total amount of water used per revenue improved by 27% in 2021 compared to the previous year, due to the significant sales increase.

Changes in Total Consumption
Changes in Total Amount of Water Used

Effective Use of Water Resources at Renesas' Manufacturing Sites

More than 95% of Renesas' water resources are used at its manufacturing sites, and about 90% of them are used in the front-end processes (wafer manufacturing processes). The figure below (summary of Renesas water cycle) is an example of the water cycle system at Renesas' front-end process production base. Wastewater used in the manufacturing process is sent to a water purification plant through a water recycling facility within our company and refined again. The purified water is reused in the manufacturing process and used as cooling water for the equipment in the cooling tower, and then purified to a safe state in the wastewater plant before being discharged. Renesas strives to use the latest equipment and technology in its water circulation system to the extent applicable.

Water Resource Circulation Diagram


Risk Management for Water Resources

Identifying Regions with Water Risks and Evaluating Water Risks in Manufacturing Sites

Water risk assessment at Renesas Group manufacturing sites uses the world map and information tool "WRI AQUEDUCT" provided by the World Resources Institute (WRI), and identifies high-risk areas, such as for drought, at each site.

As a result of the evaluation, two of our manufacturing sites (Beijing and Suzhou) in China were identified as areas with high water risk, and we will continue to consider the need for countermeasures in the future. The total water usage of those two factories in China (Beijing and Suzhou) in areas with high water stress (tight water supply and demand situation) in 2021 was 365,350 m3, which was about 2% of the total usage by the Group.

Water Resource Conservation Measures for Manufacturing Sites in High Water Risk Regions

At our manufacturing sites (Beijing and Suzhou) in high water risk areas identified by the water risk assessment, we have set improvement targets for water use per production related revenue (basic unit with the shipment value as the denominator) and strive to conserve water resources by making continuous improvements.

Achievements and Goals for Water Resource Conservation in China

Renesas Semiconductor (Beijing) Co., Ltd.'s water use per production related revenue in 2021 improved by 7% compared to 2020. In 2022, we aim for an 8% improvement with 2021 as the base year.

Renesas Semiconductor (Suzhou) Co., Ltd.'s water use per production related revenue during the same period improved by 2% compared to 2020. In 2022, we aim for a 10% improvement with 2021 as the base year.

Changes in Water Intake and Displacement of Sites in China

Basic unit (water usage / shipment value) 
improvement rate



Renesas Semiconductor (Beijing) Co., Ltd. 7% 8%
Renesas Semiconductor (Suzhou) Co., Ltd. 2% 10%

Measures to Improve Water Use Per Production Related Revenue Water Usage

  Renesas Semiconductor (Beijing) Co., Ltd. Renesas Semiconductor (Suzhou) Co., Ltd.
Water Use Reduction Measures
  • Reduction of the amount of pure water used by changing the cleaning method in the plating and water washing process
  • Reduction of the amount of primary pure water used for cleaning by improving the frequency of secondary pure water regeneration
  • Reduction of the amount of cooling water replenished by increasing the efficiency of the cooling tower (improving cooling efficiency)
  • Continued water-saving activities for domestic water and greening water
  • Reduction of the amount of cooling water used by updating the cooling tower pipes
  • Reduction of the amount of water used by changing the tester equipment cooling method (air cooling ⇒ water cooling)
  • Continued water-saving activities for domestic water and greening water
Efficiency Measures
  • Recycling wastewater from the plating / washing process
  • Recycling BG polishing wastewater, dicing cooling water, and vacuum pump cooling water
  • Utilization of pure water RO membrane

Water Usage by Sites Based in China (water intake), Total Use (including recycling), and Changes in Displacement Amount

    2018 2019 2020 2021
Renesas Semiconductor (Beijing) Co., Ltd. Usage (Water intake) (㎥)  301,504 211,743 166,348 220,532
Total use (㎥) 325,938 254,680 190,061 246,189
Displacement (㎥) 241,203 169,394 133,078 154,501
Renesas Semiconductor (Suzhou) Co., Ltd. Usage (Water intake) (㎥)  126,322 128,850 134,917 144,818
Total use (㎥) 126,322 155,060 162,892 169,870
Displacement (㎥) 88,425 90,195 94,442 101,367

Collaboration with Suppliers and Communities for Water Resources Conservation

Collaboration with Suppliers

Renesas joined the Responsible Business Alliance (RBA) in 2021 and revised the "Renesas Supplier Code of Conduct." Among the items specified in this Code of Conduct, the following are required for water management and we ask our suppliers to support them. We have received the consent and approval of all important business partners (64 companies) for this Code of Conduct, as well as many suppliers we have.

  • Document, characterize, and monitor water sources, water use and discharge, discover water-saving opportunities, and implement water management programs to control pollution routes
  • Characterize, monitor, and control all wastewater and implement necessary treatments before discharge or disposal
  • Regularly monitor wastewater treatment systems and water tanks to ensure optimal operation and compliance with regulations.

Click here for the Renesas Supplier Code of Conduct

Collaboration with the Community

With a goal to conserve water resources, Renesas is working to resolve water-related issues through collaboration with stakeholders in the watersheds of our manufacturing sites. Especially at Renesas Semiconductor (Suzhou) Co., Ltd., we are jointly managing and reporting information such as flow rate and pH related to wastewater discharge to the Environmental Protection Bureau every hour on an online monitoring system. This is done as a safety measure to conserve water resources and safely drain wastewater.
<Case Study> Online monitoring system of wastewater discharge
(net data transmission to the Environmental Protection Agency, once an hour)
Online monitoring system of wastewater discharge

Wastewater Management

Renesas considers the quality of drainage to minimize the impact on the surrounding environment during the process. All of Renesas Group’s manufacturing sites comply with the laws and regulations of each country and region, and set and manage voluntary wastewater standards above the regulatory level.

Compliance with Related Laws and Regulations

Number of violations of wastewater-related laws, environmental accidents, and complaints 2018 2019 2020 2021
Violation of laws and ordinances 0 0 1 0
Complaints 0 0 0 0

Support for Environmental Initiatives

Our Participation in the Ministry of the Environment’s Water Project


Renesas joined the "Water Project" in February 2022 as part of its ongoing efforts to conserve water resources. The "Water Project" was launched by the Ministry of the Environment of Japan as a public-private partnership initiative to increase commitment to maintain or restore a healthy water cycle based on the Water Cycle Basic Law that took effect in 2014. 

Through this initiative, Renesas will introduce our efforts to conserve water resources and share information about the importance of water resources and our contributions.

Yamaguchi Factory: Forests for Conserving Water

In Yamaguchi Prefecture in Japan, we are working to create healthy and diverse forests in order to sustainably utilize the multi-faceted functions of forests, such as water source recharge, prevention of disasters in mountainous area, and prevention of global warming.

In order to support the forests as our asset shared with the people of Yamaguchi Prefecture, the 12th “Water-Protecting Forest Development Activity” was held in November 2019 with a goal to promote voluntary activities by corporations. A total of 199 employees and administrative officials from neighboring companies participated, and eight employees from our Yamaguchi Factory also participated. In this activity, we improved forests around the Akiyoshidai Family Holiday Village located north of our Yamaguchi Factory, which is the source of the Atsugashi River where our factory takes water for production use.

(The Yamaguchi Factory of Renesas Semiconductor Manufacturing Co., Ltd. closed at the end of June 2022.)

Yamaguchi Factory image01
Yamaguchi Factory image02
Yamaguchi Factory image03


Contributing to SDGs

Renesas’ efforts in Conserving Water contributes to these Sustainable Development Goals targets:


6.3 By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally


6.4 By 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity and substantially reduce the number of people suffering from water scarcity


6.6 By 2020, protect and restore water-related ecosystems, including mountains, forests, wetlands, rivers, aquifers and lakes


6.b Support and strengthen the participation of local communities in improving water and sanitation management