SASB-Based Information Disclosure

The status of HEPCO Group performance and initiatives are stated in accordance with the United States Sustainability Accounting Standards Board (SASB) industry-specific standards for electric utilities & power generators. The SASB standards were prepared envisioning mainly companies and markets in the United States, so they also include items that do not correspond to business activities in Japan. HEPCO has endeavored to disclose as much information as possible in accordance with the SASB standards.

Quantitative data without a specific time indicated is as of the end of FY2025

Topic	Accounting Metric	Category	Unit	Code	Performance
Greenhouse Gas Emissions & Energy/Power Plan	(1)Scope 1 emissions (total global emissions) (2)Ratio of Scope 1 emissions subject to emission regulations (3)Ratio of Scope 1 emissions subject to mandatory emission reporting	Quantitative	t-CO2-e % %	IF-EU·110a.1	(1)11,970,000t-CO2 (2)99% (3)100%
	Greenhouse gas emissions associated with power supplied	Quantitative	t-CO2-e	IF-EU·110a.2	12,420,000t-CO2
	Consideration of strategy & plan for managing Scope 1 emissions over the short- and long-term Emissions reduction targets Analysis of performance vis-à-vis above targets	Consideration & analysis	-	IF-EU·110a.3	The Hokuden Group will make every effort to achieve carbon neutrality for all energy in Hokkaido by 2050. Emission Reduction Targets For the Hokuden Group's supply chain emissions (Scope 1+2+3), we will strive to reduce emissions by 46% by fiscal 2030 and 60% by fiscal 2035 compared to fiscal 2013 levels. Reduction Plan On the supply side, we will advance the early restart of the Tomari Power Plant, expand renewable energy adoption, and decommission aging thermal power plants. We will also promote the decarbonization of thermal power plants through the utilization of hydrogen and ammonia, and the introduction of CCUS (carbon capture, utilization, and storage). On the demand side, we will expand solution services such as promoting electrification and supplying renewable energy to customers across all sectors-residential/commercial, industrial, and transportation. For customers where electrification is difficult, we will promote the use of decarbonized fuels. Analysis of Achievement CO2 emissions are trending downward, partly due to the utilization of the Ishikari Bay New Port Power Plant, a high-efficiency LNG thermal plant with low CO2 emissions. (FY2024 CO2 emissions from the power generation sector: 11.56 million tons)
Air Quality	Emissions of the following pollutants into the atmosphere and percentage of each in or near densely-populated areas (1)NOX (excluding N2O) (2)SOX (3)Particulate matter (PM10) (4)Lead (Pb) (5)Mercury (Hg);	Quantitative	t %	IF-EU·120a.1	(1)8,500t, 93% (2)6,400t, 99% (3)Undisclosed (4)Undisclosed (5)Undisclosed
Water Resource Management	(1)Total water withdrawn (2)Total water consumed; Percentage of each in regions with high or extremely high baseline water stress	Quantitative	(1)1,000m3 (2)1,000m3 %	IF-EU·140a.1	(1)21,000,000,000m3, 0% (2)1,500,000m3, 0%
	Number of non-compliance incidents associated with water intake and water quantity	Quantitative	Incidents	IF-EU·140a.2	0 incidents
	Explanation of water resource management risks and consideration of risk mitigation strategies and implementation	Consideration & analysis	-	IF-EU·140a.3	The following initiatives have been carried out in an effort to ascertain and mitigate water-related risks. To ascertain the impact of water-related risks, the World Resources Institute's Aqueduct tools have been used to verify the state of water stress in areas where HEPCO Group facilities are located. Water stress has been classified as "low," so we do not believe water stress has a significant impact on operations. [Thermal power generation facilities] Water used for cleaning equipment and other wastewater generated during power plant operation is passed through a comprehensive wastewater treatment system or other such facility to separate oils, remove solids, neutralize effluent, and perform other functions so that the water may then be released as clean water. The difference between water intake and drainage temperatures as well as other parameters are monitored to investigate the effect that water releases have on the sea environment. In accordance with the Water Pollution Prevention Act's effluent standards, pollution control agreements entered into with local governments, and other mandates, HEPCO sets management values and strives to prevent water pollution. [Hydroelectric power generation facilities] The HEPCO Group complies with water intake quantities for which permits have been received in accordance with laws and regulations. At hydroelectric power plants that meet certain conditions, water is released to maintain the river environment. Sectors where the water level may fall due to water intake for hydroelectric power generation are required to be 10 km or longer in length with a catchment area of 200 km2 or larger.
Coal Ash Management	Amount of coal ash generated and percentage recycled	Quantitative	t %	IF-EU·150a.1	540,000t, 87%
Coal Ash Management	Explanation of the management policy for Coal Combustion Products (CCP), and procedures for operations handling active and inactive CCPs	Consideration & analysis	-	IF-EU·150a.3	The 3Rs - Reduce, Reuse, and Recycle - are promoted to address the issue of processing industrial by-products. Initiatives have also been advanced that contribute to creating a circular society. We have strived to research and develop technologies to effectively make use of coal ash as a recycled resource in particular because it accounts for a large portion of the industrial by-product from coal-fired thermal power plants. Coal ash is widely used in a variety of sectors, such as civil engineering and construction in applications for cement raw material, concrete, tunnel spraying, and road base material, the environmental sector in applications for treating sludge at construction sites, as well as the agricultural sector in applications such as an anti-mud agent for livestock paddocks. Planning and performance are managed for both effective utilization and final disposal of coal ash so that coal ash management efforts may be better assessed. In addition, in cooperation with HEPCO Group companies and our partners, we have established a system that provides guidance on coal ash management to facilitate coal ash management initiatives.
Energy Affordability	Average electric rates (per 1 kWh) for (1) residential, (2) commercial, and (3) industrial customers	Quantitative	yen	IF-EU·240a.1	(1) 33.39 [JPY] (2) and (3) total: 27.76 [JPY] (Total electric power) Including amount equivalent to consumption taxes and other charges. Calculation excludes the renewable energy surcharge.
	(1)Number of cases where supply shutoff due to nonpayment of electricity charges (residential) (2)Ratio of resumptions within 30 days	Quantitative	Shutoff %	IF-EU·240a.3	(1)38,035 Number of disconnections due to nonpayment of electric bill Excludes number of supply shutoffs pursuant to the General Provisions for Specified Retail Service (2)None Cases where an electric bill has not been paid after the due date are stipulated to be revocation of the supply contract in accordance with the Electricity Standard Terms and Conditions (contract cancellation). Because supply shutoffs and resumptions are not specified in the Electricity Standard Terms and Conditions, this item is listed as "None."
	Consideration of the impact of external factors relating to ease with which consumers may access electric power (including economic conditions in the electric power supply service area)	Consideration & analysis	-	IF-EU·240a.4	The Electricity Business Act stipulates: "A general electricity transmission and distribution utility must not refuse to provide a wheeling service in its service area without justifiable grounds." As Hokkaido Electric Power Network, in principle, provides service to all customers who request it within the Hokkaido Electric Power Network service area, there is no difference in accessibility to electricity. Other external factors affecting electricity rates include the policy-mandated surcharge for promoting renewable energy generation, the fuel cost adjustment amount, and rate discounts provided through the national electricity and gas rate relief support program.
Occupational Health & Safety	Figures below are for each employee employed by (a) HEPCO and (b) contractors (1)TRIR (Number of work-related incidences per 200,000 hours worked) (2)Rate of fatalities resulting from work-related incidents (3)NMFR (Number of near miss events in the workplace per 200,000 hours worked)	Quantitative	%	IF-EU·320a.1	(1)0.58 [%] (a. HEPCO employees) (2)0 [Fatalities] (a. HEPCO employees) (3)Undisclosed (Total near-miss incidents are not tabulated for the entire company, so this item is given as undisclosed.)
End-Use Energy Efficiency & Demand	Ratio of electricity supplied (MWh) that is delivered over smart grids	Quantitative	%	IF-EU·420a.2	Percentage of meters converted to smart meters as of the end of March 2025: 100% (Smart meters have been installed for all customers (approx. 3.74 million units), except for some sites where meter replacement is difficult.)
End-Use Energy Efficiency & Demand	Reduction in electric power achieved through energy-saving initiatives	Quantitative	MWh	IF-EU·420a.3	The following quantitative data is disclosed in lieu of the amount of electric power reduced. FY2025 energy-saving, electrification and ZEB proposals: approx. 2,000 (companies) * HEPCO proposes a variety of solutions to our customers to help them meet their electrification and energy-saving needs. (See https://www.hepco.co.jp/business/total_solution/index.html)
Nuclear Safety & Crisis Management	Total number of nuclear power units (Based on classification using U.S. Nuclear Regulatory Commission (NRC) Action Matrix Column)	Quantitative	Number of units	IF-EU·540a.1	3 units (3 units at Tomari NPS) *Currently, all three units at Tomari NPS are shutdown, and HEPCO is responding to the review by the Nuclear Regulation Authority to verify compliance with new regulatory requirements.
Nuclear Safety & Crisis Management	Explanations of nuclear safety management and crisis management (preparations for emergencies)	Consideration & analysis	-	IF-EU·540a.2	Each and every HEPCO employee recognizes that he or she is responsible for safety and continually works to foster and maintain a safety culture. HEPCO's efforts to enhance safety include formulation and annual reassessments of safety improvement plans based on our value that safety is the highest priority. One example of this commitment may be seen in HEPCO Group's establishment and reinforcement of the Corrective Action Program (CAP), an initiative for broadly collecting information as well as detecting and resolving issues voluntarily in order to prevent nonconformances from happening and recurring. At Tomari Nuclear Power Station, we implement multiple and diverse safety measures to ensure that functions safeguarding the plant's safety-such as power sources and cooling systems-are not lost due to natural phenomena like earthquakes or tsunamis. We also install equipment to prepare for severe accidents and conduct ongoing training using this equipment. We will continue to consistently review and implement risk reduction measures, building upon our efforts to further enhance the safety of Tomari Nuclear Power Station.
Grid Resiliency	Number of code and regulatory non-compliance incidents relating to cybersecurity and/or physical risks	Quantitative	Number of incidents	IF-EU·550a.1	Undisclosed (Out of consideration of the risks that disclosure may lead to a cyber attack, the number of instances is given as "undisclosed.")
Grid Resiliency	(1)Average annual service interruption time (System Average Interruption Duration Index (SAIDI)) per user (2)Average annual number of service interruptions (System Average Interruption Frequency Index (SAIFI)) per user (3)Average time until restoration after one service interruption (Customer Average Interruption Duration Index (CAIDI))	Quantitative	(1)Minutes (2)Times (3)Minutes	IF-EU·550a.2	(1)4 minutes (2)0.07 interruptions (3)62 min./ interruption

Activity Metric	Category	Unit	Code	Performance
Number of customers (1) Residential, (2) commercial, and (3) industrial	Quantitative	Number of units	IF-EU·000.A	(1) 2.89 million (total lights) Total for (2) and (3): 350,000 (total lights)
Total electricity supplied to: (1) residential, (2) commercial, (3) industrial, (4) other, and (5) wholesale customers	Quantitative	MWh	IF-EU·000.B	(1) 7,805 [GWh] Total for (2) and (3): 14,924 [GWh] (4) 71 [GWh] (5) 10,770 [GWh]
Length of transmission and distribution lines	Quantitative	km	IF-EU·000.C	Length of power transmission and distributions lines as of the end of March 2025 [Transmission lines] Overhead: 12,454km, Underground: 756km [Distribution lines] Overhead: 66,639km, Underground: 1,791km
Total power generated Ratio of power generated from key resources Ratio of power generated in regulated markets	Quantitative	MWh % %	IF-EU·000.D	Total electricity generated: 19,276GWh, of which hydroelectric power is 15.5%, thermal power 83.9%, nuclear power: none, and new energies: 0.6%. Japan has no regulated markets.
Amount of wholesale electricity purchased	Quantitative	MWh	IF-EU·000.E	17,427 [GWh]