GRI 2-12, 2-13, 2-14, 2-27, 3-1, 3-2
Step 1

Identification

Step 2

Assessment and Prioritization

Step 3

Validation

Step 4

Review and Response

Process

Relevant issues impacting the sustainability of GPSC and its stakeholders throughout the value chain across economic, social and environmental dimensions are identified through the consideration of impacts (positive and negative); the expectations, interests, and concerns of all eight stakeholder groups (shareholders, investors, government agencies, employees, suppliers, partners, customers, communities, and communities and society); as well as changes in global trends and the industry, past events, risk factors with potential impacts in the future, business opportunities, GRI Standards indicators, and human rights principles.

GPSC operates in strict compliance with the law and applies various international guidelines to its operations, with dedicated compliance units and audit systems in place to ensure compliance. In addition, GPSC has put in place whistleblower channels and an effective due diligence process. In 2025, no violation of the law or relevant regulations was reported.

Guidelines
  • PTT Group’s and GPSC’s Sustainable Development Guidelines
  • Sustainable Development Goals (SDGs)
  • International guidelines, such as GRI1, DJSI2, SDGs3, WBCSD4, CDP5, ISO 260006, UNGC7, IIRC8, and others
  • All internal and external stakeholders’ voices
  • Community satisfaction surveys
  • Employee engagement surveys
  • Customer satisfaction surveys
  • Corporate image improvement process
  • Complaint channels
  • Corporate risk assessment
Process

Assessing key sustainability issues in the Double Materiality format involves evaluating impacts on the environment, society, and stakeholders (external) as well as the impact on the company (both financially and non-financially). This process takes into account the opinions and expectations of stakeholders by collecting data through interviews with selected external stakeholders, using a purposive selection method, and through online surveys for internal stakeholders. The collected data from stakeholders will be analyzed in the form of scores assigned to key issues based on the criteria of severity and likelihood of impact, both on the company and on the environment, society, and stakeholders. Subsequently, the key issues will be grouped using a rating scale. Material issues then categorized into two groups using a rating scale based on their severity: 1) key material issues, which are issues with high and very high impact ratings, and 2) fundamental material issues, which are issues given low and medium ratings. The latter are issues that GPSC is legally mandated.

Guidelines
  • External stakeholder interviews
  • Online opinion surveys for internal stakeholders
  • Impact assessment and categorization based on the level of impact
  • Materiality prioritization
Process

A summary of material issues is reported to GPSC. The material topics are tested by experts to ensure that they are in line with global trends and cover all issues in the electricity generation industry as well as to ensure alignment with GRO aspects. The material issues are then proposed to responsible internal units for the subsequent formulation of management strategies and guidelines.

GPSC’s Management Committee (GPSC MC) is responsible for validating and approving the content of the material issues as well as assigning relevant units to prepare management plans for the impacts of such material issues. In addition, GPSC MC is charged with reviewing the reported data to ensure its transparency, accuracy, and compliance with reporting requirements in accordance with GRI Standards indicators to disclose in the Annual Integrated Sustainability Report.

Guidelines
  • Material issue validation by experts or third-party assurance provider
  • Meeting and review of material issues by GPSC’s executives
Process

GPSC consistently reviews and improves Integrated Sustainability Report and conducts validation to ensure that the material issues that need to be managed meet stakeholder expectations. In addition, GPSC has developed the stakeholder participation process by obtaining stakeholder voice and suggestions through various communication channels, such as by participating in sustainability reporting assessment by the Securities and Exchange Commission and the Thaipat Institute. These efforts are essential to the improvement of reporting quality and reflect issues that stakeholders consider vital in a more effective way.

Guidelines
  • Third-party sustainability report validation
  • Receiving complaints and suggestions through various channels
  • Sub-group meetings of sustainability units to review sustainability reporting and sustainability development performance as assigned
  • Quarterly report of the implementation of sustainability plans to GPSC’s executives
Remark:

1 Global Reporting Initiative (GRI) is the organization that initiates international report standards which are used as a prototype for sustainability report preparation.

2 Dow Jones Sustainability Indices (DJSI) are a family of capital indices that assesses the effectiveness of business operations according to sustainable development guidelines of the world’s leading companies and is used as investment criteria by various funds worldwide.

3 FTSE Russell ESG Score refers to the score resulting from the assessment of a company's performance in Environmental, Social, and Governance (ESG) practices

4 MSCI (Morgan Stanley Capital International) is a leading global provider of equity indices and financial analytics, whose benchmarks are widely used by institutional investors and investment funds around the world.

5 World Economic Forum is an international organization that promotes cooperation between the public and private sectors to address major global challenges, including sustainable development.

6 Sustainable Development Goals (SDGs) are of a set of sustainable development goals stipulated by the United Nations (UN), comprising 17 main objectives to be achieved and implemented by 2030.

7 World Business Council for Sustainable Development (WBCSD) is the committee of businesspersons for the environment that comprises over 120 leading international companies and was accepted in the Earth Summit in 1992.

7 SASB (Sustainability Accounting Standards Board) is an organization that developed industry-specific sustainability disclosure standards to help companies communicate environmental, social, and governance (ESG) issues that are financially material to investors.

8 IFRS (International Financial Reporting Standards) are internationally recognized financial reporting standards that provide a set of accounting principles and requirements for the preparation and presentation of financial statements.

9 IFC International Finance Corporation is an international financial institution that promotes private sector investment in developing countries. It is a member of the World Bank Group

10 ADB Asian Development Bank is a regional development bank that provides loans, grants, and technical assistance to support economic and social development across Asia and the Pacific

11 Carbon Disclosure Project (CDP) is a global institution given the highest level of recognition in terms of environmental management assessment.

12 ISO 26000 is an international standard for social responsibility.

13 UN Global Compact (UNGC) is a United Nations initiative that serves as guidelines for formulating strategies and practices in line with international accepted principles in the areas of human rights, labor, environment, and anti-corruption efforts.

14 International Integrated Reporting Council (IIRC) is a council on integrated reporting, which refers to a report on an operation’s operations in accordance with its business strategies, corporate governance, as well as its performance and outcomes that contribute value to the organization and internal and external stakeholders over the short, medium, and long term.

GPSC’s Double Materiality Assessment 2025
GRI 3-1, 3-2, 3-3

The 2025 assessment of material issues concerning sustainability found changes in external factors that have caused positive as well as negative impacts and creation of long-term values for stakeholders and the business. Pressure from both internal and external sources that has led to these changes involve such issues as self-adjustment to cope with the fluctuating economy, attempt to reduce GHG emissions to tackle climate change, geopolitical conflicts and energy crisis, the changing market demand, and the evolving pattern of energy consumption, together with human rights and biodiversity, both of which have gained increasing attention globally.

Material Issue
Key Material Issue
Clean Energy Towards Net Zero
Environmental Management
Evolving Business Model
Employee-focused Organization
Fundamental Material Issue
Biodiversity
Corporate Social Responsibility
Occupational Health and Safety
Supply Chain Management
Governance, Risk Management, and Compliance
Maintaining Availability and Reliability
Customer Relationship Management
Remarks:
Key Material Issues

are issues whose effects in various aspects, namely economic (corporate governance), social, and environmental, are recognized by internal and external stakeholders. Both positive and negative impacts are scored by their levels of impacts (high to very high impact) on internal and external stakeholders as well as on the business, taking severity and probability of risks into consideration.

Fundamental Material Issues

involve basic requirements for the company in compliance with general laws, standards, and practices, which internal and external stakeholders view as issues of low to moderate impacts.

The material issues, which are the results from Materiality assessment, are then integrated as the inputs into Company's Enterprise Risk Management Process (ERM) in order to prepare business strategy and risk management plan that can meet stakeholder expectations as well as business goals as shown in the picture below.

The material issues were taken into company risk identification process (process 1), as supplementary inputs, together with the potential changes for both external and internal factors for identifying corporate risks. Moreover, the key material issues were also used for cross-checking the significant corporate risks with the linkage as shown in the below table.

Key Material Issue Risk Area Linkage to Corporate Risk
Clean Energy Towards Net Zero Strategic Risks Climate Change
Environmental Management Operational Risks Quality, Security, Safety, Health, and Environment
Employee-focused Organization Strategic Risks Organizational Capability
Evolving Business Model Strategic Risks Investment and Business Growth
GPSC’s Double Materiality Assessment 2025

In 2025, the Company has assessed the key sustainability issues. They are divided into 4 key material issues and 7 fundamental material issues. The details of the impact on the company and external stakeholders, including shareholders, investors, government, employees, suppliers, partners, customers and communities, (according to the Double Materiality Principle) as follows:

GPSC Materiality Assessment Approval
Material Issue Impacts
(Positive and negative)(1)
Occurrence Related
Stakeholder
Financial Impact
on the Company(2)
Global
reporting
Initiative: GRI
Alignment with
Sustainable
Development Goals
(SDGs)
Past and
present
Future
Key Material Issue
Clean Energy Towards Net Zero
  • GPSC’s clean energy enables customers to reach their net-zero goals faster, thereby fostering trust and opportunities for business partnerships in the long term.
  • GPSC’s reduction of Scope 3 emissions contributes to the advancement of supply chain carbon management and national net-zero targets
  • Legal constraints and industrial estate regulations can hinder the installation of clean energy systems for customers, limiting their energy management flexibility and sustainability investment opportunities
Shareholders, Government/public, customers, suppliers, investors, partners, employees, society and communities
  • Management Approach (3-1, 3-2, 3-3)
  • Energy (302-1, 302-3, 302-4)
  • Emission (305-1, 305-2, 305-3, 305-4, 305-7)
Environmental Management
  • Water treatment and recycling in the production process reduce freshwater withdrawal from natural sources and mitigate impacts on surrounding communities
  • Circular waste management reduces pollution generated and fosters community trust towards GPSC’s operations
  • Air emissions, such as dust, odor, and smoke, from power plant operations can affect the health and quality of life of nearby communities
  • Failure to meet effluent discharge or industrial waste management standards can disrupt local ecosystems
Shareholders, Investors, Government Sector, Society and Communities, Customers
  • Strategy, Policies, and Practices (2-23, 2-24)
  • Management Approach (3-1, 3-2, 3-3)
  • Water (303-1, 303-2, 303-3, 303-4, 303-5)
  • Emissions (305-7)
  • Effluents and Waste (306-1, 306-2, 306-3, 306-4, 306-5)
  • Environmental Compliance (307-1)
Evolving Business Model
  • Energy storage innovations reduce fossil fuel dependency and support a sustainable transition to clean energy
  • The prompt adaptation to changes in global energy trends builds shareholder and investor confidence
  • The adoption of AI and new technologies may lead to employee concerns regarding job security.
Shareholders, Investors, Government Sector, Customers, Suppliers
  • Management Approach (3-1, 3-2, 3-3)
  • Indirect Economic Impacts (203-1)
Partners
Employee-focused Organization
  • A safe working environment and the adoption of fair labor practices improve the quality of life for employees.
  • Promoting diversity, equity, and inclusion (DEI) and supporting female leadership fosters an inclusive and open organizational culture.
  • Excessive workloads in certain roles can negatively impact employee well-being and productivity
Shareholders, Investors, Employees, Government/ public
  • Management Approach (3-1, 3-2, 3-3)
  • Collective bargaining agreements (2-30)
  • Training and Education (404-1, 404-2, 404-3)
  • Diversity and Equal Opportunity (405-1, 405-2)
  • Freedom of association and collective bargaining (407-1)
Fundamental Material Issue
Biodiversity
  • Protects ecosystems, benefiting local communities and future generations.
  • Strengthens reputation among stakeholders through conservation efforts.
Shareholders, Investors, Government Sector, Society and Communities
  • Management Approach (3-1, 3-2, 3-3)
  • Biodiversity (304-1, 304-2, 304-3, 304-4)
Corporate Social Responsibility
  • Enhance brand reputation through meaningful contributions to societal well-being.
  • Improve living standards for people in the surrounding communities through sustainable self-reliance.
  • Employee participation in CSR activities enhances their skills, aligns them with the company’s strategies, and fosters organizational ownership and engagement.
Society and Communities, Employees, Shareholders
  • Management Approach (3-1, 3-2, 3-3)
  • Local Communities (413-1, 413-2)
Occupational Health and Safety
  • Ensures employee well-being, reducing workplace accidents and fostering trust.
  • Promotes a safe and inclusive environment, benefiting society and local communities.
  • Reduces environmental risks through safer operational practices.
  Suppliers, Employees, Society and Communities
  • Management Approach (3-1, 3-2, 3-3)
  • Occupational Health and Safety (403-1, 403-2, 403-3, 403-4, 403-5, 403-6, 403-7, 403-9, 403-10, EU-25)
Supply Chain Management
  • Impact GPSC’s operating results and operational continuity
  • Impact the corporate image
  • Ethical sourcing and transparency build trust with customers, investors, and partners.
  • Promotes fair labor practices, benefiting communities and regulators.
Shareholders, Investors, Suppliers
  • Management Approach (3-1, 3-2, 3-3)
  • Health and Safety for Contractor and Subcontractor Employees (EU-17, EU-18)
Governance, Risk Management, and Compliance
  • Fostering confidence in GPSC’s business operations among stakeholders
  • Exchanging knowledge on compliance and business code of conduct
  • Promotion of continuous and sustainable growth through good corporate governance across all dimensions (ESG)
  • Fostering stakeholder confidence through systematic risk management for the prevention of potential impacts
  • Potential new risks for operations and impacts on GPSC’s operating results and service provision, especially on overseas investment
  • Impact on confidence in GPSC if there is a lack of proper management
Shareholders, investors, partners, customers, suppliers
  • Management Approach (3-1, 3-2, 3-3)
  • Organization Profile (2-11)
  • Governance (2-9, 2-10, 2-11, 2-12, 2-13, 2-15, 2-16, 2-23, 2-24, 2-25, 2-26, 2-27)
  • Anti-corruption (205-3)
Maintaining Availability and Reliability
  • Foster customer confidence, which continuously affects GPSC’s operating results
  Shareholders, Investors, Customers, Employees
  • Management Approach (3-1, 3-2, 3-3)
  • System Efficiency (EU-1, EU-2, EU-11)
  • Demand Side Management (EU-10)
  • Availability and Reliability (EU-28, EU-29, EU-30)
  • Foster confidence, leading co-creation of business value
  • Foster marketing stability for suppliers
  • Reduces energy costs and enhances stakeholder trust.
  • Lowers greenhouse gas emissions, benefiting the environment and society.
  • Ensures reliable services, meeting customer and community needs.
  Partners, Suppliers
Customer Relationship Management
  • Foster corporate credibility
  • Maintain operational continuity
  • Impact the corporate image
  • Take proactive measures in maintaining and building customer relationships.
Partners, Customers
  • Management Approach (3-1, 3-2, 3-3)

Note:

(1) Impacts, in each material issue both are actual and/or potential, can be considered in positive and negative.

(2) Financial impact on the Company sorted by the number of blue dots that appear in the table, divided into 4 groups:

  • 4 blue dots mean the impact or opportunity from that material issue in the financial aspect to the Company at a “very high” level
  • 3 blue dots mean impact or opportunity from that material issue in financial aspect to the Company at a “high” level
  • 2 blue dot means impact or opportunity from that material issue in financial impact on the Company at a “Moderate” level and
  • 1 blue dot means impact or opportunity from that material issue in financial impact on the Company at a “low” level
Targets and Executive Compensations linked to the top material issues

GPSC has established the targets linked to the top material issues to effectively drive sustainability performance in long-term. The targets have set in three timeframes comprising annual, short-term and long-term targets. To achieve the targets and maintain the performance, GPSC dedicates responsibilities to employees from executives level to staff level to manage material issues as KPIs which are linked to annual its performance appraisal. The achievement of this KPI will be linked to the compensation consideration of relevant executives.

This ensures that the ambitions and targets are embedded throughout the company and that management is held accountable for the achievement of these goals as shown in the table below:

Material Topic 2025 Target Short- and long-term targets Type of
Incentive
Incentivized KPIs for
Executives
Clean Energy toward Net Zero
  • Direct and indirect GHG emissions (Scopes 1 and 2): not exceeding 12,000,000 tCO2e
  • Decrease GHG emission intensity by 10% and 35% by 2025 and 2030 (compared to the base year of 2020)
  • Achieve net zero emissions by 2050
  • Increase the proportion of renewables to over 50% by 2030
  • Achieving 10,000-rai reforestation target by 2030
Monetary
  • Eco-efficiency improvement (absolute GHG emission reduction/year from energy efficiency improvement)
  • Renewable MWe Growth
  • Achievement of Net Zero roadmap milestones
Evolving Business Model
  • Develop investments in New S-Curve innovations, such as decarbonization technologies, decentralized power generation, and district cooling systems
  • Over 50% of the portfolio derived from renewables by 2030
  • Strengthen partnerships in clean energy technologies, focusing on zero-GHG power generation through solar, wind, and energy storage system (ESS) integration.
  • Emphasize investments in Thailand and abroad, aligning with national strategies and renewable energy targets under Thailand’s Power Development Plan 2024 and related policies.
  • Seeking new business opportunities by developing end-to-end energy services with a focus on integrated energy management platforms and smart systems.
  • Explore reliable baseload power solutions such as carbon capture and storage (CCS), hydrogen, and small modular reactors (SMRs) to align with future energy trends.
Monetary
  • Revenue/EBITDA contribution from new businesses
  • Achieved MW growth (MW equity) with new investment (platform or partners)
  • Successful execution of strategic investments (New Business / S-Curve / S3 & S4)
Employee-focused Organization
  • 100% succession planning for key positions
  • Lower turnover rate than the previous year
  • Employee engagement level equal to or no more than 3.0% lower than Thailand’s market average
  • Promoting learning and enhancing employee capabilities in functional work and new businesses to support the Company’s strategic plan
  • Developing and retaining high- potential talent to build a pipeline of future leaders
  • Continuously develop employee capabilities through reskilling, upskilling, and modern learning programs in areas like digital transformation, AI, automation, and renewable energy. Strengthen leadership skills and foster knowledge transfer through executive mentorship to prepare for future organizational needs.
  • Strengthen talent attraction and retention through AI-driven recruitment, enhanced employer branding, and improved candidate experience. Support employee well-being with flexible work models and comprehensive benefits to ensure long-term engagement and satisfaction.
Monetary
  • Employee engagement score
  • Succession planning coverage for key positions
  • Talent retention
The External Impact Value from GPSC’s Activities

Impact 1 - Climate Transition & Physical Risks from the key material issue “Clean energy towards Net Zero”

Cause of the impact - The impact caused by the operation of the business value chain with >50% of business activity coverage.

Impact area(s) evaluated Environment & Society area.

Type of the evaluated impact – Positive

Rationale

GPSC assessed the impacts since it is material to the environment and society due to global concern of climate change issue. This also directly involves with GPSC operation as currently using fossil fuel as a source for power generation. GPSC, as a power producer and significant GHG emitter, considers the Clean Energy toward Net-Zero as one of the key material issues. GPSC has already set business direction towards net zero target. All the process to achieve the target needs employee to contribute. GPSC climate-related targets including GHG emission reduction, increase of national renewable energy and Nationally Determined Contribution achievement for both national and site-specific level. GPSC as an energy provider is the key player contributing to these targets by providing low carbon energy and other products. GPSC implemented several activities to avoid and mitigate those GHG emissions in several ways. GPSC also support national climate-related targets, join and support external climate-change networks to build on and promote low-carbon business and practices. GPSC is heading the business towards climate change, clean energy,and net zero directions, there might be more business opportunities for suppliers/contractors in areas that require technical expertise or specific resources. These are important to evaluate externalized impacts from those activities to inform business decision, progress, strategy planning as well as how much climate related impacts the company can avoid in the environment and society. This is to encourage external parties in joining and sharing low carbon activities/practices along with the company.

External Impacts

Environmental externalities

Impact type Output Metric
(Impact Valuation)
Impact Metric Impact Metric Evaluated in 2025 Reference
Positive Greenhouse Gas Emissions Avoided (in tCO2e)* (Environmental value lost/ gained) GHG emissions avoidance* GHG avoided from fossil fuel power generation: 4,059,573 tCO2e IRIS, 2021. Greenhouse Gas Emissions Avoided (PI2764). v5.2.
Positive NOx avoidance
(Environmental value lost/ gained)
NOx avoidance NOx avoided from fossil fuel power generation: 2,656 tonnes N/A
Positive SOx avoidance
(Environmental value lost/ gained)
SOx avoidance SOx avoided from fossil fuel power generation: 321 tonnes N/A
Positive Dust avoidance
(Environmental value lost/ gained)
Dust avoidance Dust avoided from fossil fuel power generation: 241 tonnes N/A

Note: * the output metrics refer to performance metrics included in the IRIS (Impact Reporting & Investment Standards) catalog and accepted as good practice to define output targets to measure social and environmental success.

For the social externalities

Impact type Output Metric
(Impact Valuation)
Impact Metric Impact Metric Evaluated in 2025 Reference
Positive Community income generated (THB) Social Cost of Carbon Economic value was created for community enterprises through upcycling initiatives, generating annual income of THB 2,073,834 IRIS, 2021. Social Impact Objectives (OD6247). v5.2.

Impact 2 - Sustainable Products & Services from the key material issue “Evolving Business Model”

Cause of the Impact – The impact caused by the products/services and supply chain of the business value chain with >50% of business activity coverage.

Impact area(s) evaluated – Environment and consumers/ end-users

Type of the evaluated impact – Positive

Rationale

GPSC assessed the impacts as material to consumers and end-users, as they directly benefit from the company's renewable energy solutions through its solar Engineering, Procurement and Construction (EPC) and private Solar Power Purchase Agreement (PPA) businesses. With the growing demand for renewable energy, decarbonization, and energy cost optimization, GPSC has expanded its solar EPC and Solar PPA portfolio to support customers in adopting clean energy solutions. Through these initiatives, customers benefit from reduced electricity costs, lower greenhouse gas emissions, improved energy efficiency, and enhanced energy security by generating electricity from on-site solar photovoltaic systems. These activities also contribute to the broader transition toward a low-carbon energy system while creating long-term economic and environmental value for customers and other stakeholders.

External Impacts

Environmental externalities

Impact type Output Metric
(Impact Valuation)
Impact Metric Impact Metric Evaluated in 2025 Reference
Positive Greenhouse Gas Emissions Avoided (in tCO2e) (Environmental value lost/ gained) GHG emissions avoidance* GHG avoided fossil fuel power generation: 90,995 tCO2e IRIS, 2021. Greenhouse Gas Emissions Avoided (PI2764). v5.2.
Positive Renewable Energy Generated (in MWh) Energy Generated for Use: Renewable* Renewable energy generated: 226,300 MWh/year IRIS, 2021. Energy Generated for Use: Renewable (OI2496). v5.3.

Note: * the output metrics refer to performance metrics included in the IRIS (Impact Reporting & Investment Standards) catalog and accepted as good practice to define output targets to measure social and environmental success.

Social externalities

Impact type Output Metric
(Impact Valuation)
Impact Metric Impact Metric Evaluated in 2025 Reference
Positive Other Cost saving from external power purchasing of customer Maximum cost saved from external power purchasing of customer: 22,169,039 USD/year* N/A
Positive Social Cost of Carbon (USD) (Social cost caused/avoided) Social Cost of Carbon Social cost of carbon reduced through renewable energy generated: 5,295 USD/year ** IRIS, 2021. Social Impact Objectives (OD6247). v5.2.

Note:

* The value is calculated using the electricity tariff used which is 3,109.7 THB/MWh (Electricity tariff for medium-sized business, Metropolitan Electricity Authority, https://www.mea.or.th/profile/109/113) and the average exchange Rates for 2025 which is 31.74 THB/USD (Exchange Rates BOT, https://www.bot.or.th/en/statistics/exchange-rate.html). The assumptions include energy cost saving equal to cost of the energy provided by official Thai Electricity Authority replaced by self-generated energy stored in the GPSC’s product (Battery).

** The social cost of carbon (SCC) represents the marginal social damage from emitting one metric ton of carbon dioxide-equivalent at a certain point in time (in monetary unit/one excess death). The SCC can be determined by using the mortality cost of carbon (MCC) (in tCO2e emitted/ one excess death). (Bressler, R.D. The mortality cost of carbon. Nat Commun 12, 4467 (2021). https://doi.org/10.1038/s41467-021-24487-w)

Updated as of July 2026

The above content is prepared in accordance with the sustainability reporting standards by the Global Reporting Initiative (GRI Standards), which is validated by external parties and provides a limited level of assurance of reporting information (Limited Assurance).