Summary of significant accounting policies (Policies)	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Basis of presentation	In preparing the consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP), management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results could differ significantly from those estimates.
Use of estimates	Material estimates that are particularly susceptible to significant change for HEI and its subsidiaries (collectively, the Company) include the amounts reported as fair value for pension and other postretirement benefit obligations; contingencies and litigation; income taxes; regulatory assets and liabilities (Utilities only); and asset retirement obligations (Utilities only).
Consolidation	The HEI consolidated financial statements include the accounts of HEI and its subsidiaries. The Hawaiian Electric consolidated financial statements include the accounts of Hawaiian Electric and its subsidiaries. When HEI or Hawaiian Electric has a controlling financial interest in another entity (usually, majority voting interest), that entity is consolidated. Investments in companies over which the Company or the Utilities have the ability to exercise significant influence, but not control, are accounted for using the equity method. The consolidated financial statements exclude variable interest entities (VIEs) when the Company or the Utilities are not the primary beneficiaries. Significant intercompany amounts are eliminated in consolidation
Cash and cash equivalents	The Company considers cash on hand, deposits in banks, money market accounts, certificates of deposit, short-term commercial paper of non-affiliates and liquid investments (with original maturities of three months or less) to be cash and cash equivalents.
Restricted cash	The Company considers cash held by trustees, related to non-recourse loans at Pacific Current subsidiaries, and cash held by GLST1, related to the first liability installment payment pursuant to the settlement agreements to settle the tort-related legal claims in the litigation arising out of the Maui windstorm and wildfires, to be restricted cash. In addition, the Utilities consider funds on deposit with Wells Fargo, which represent collateral to secure company purchasing cards, to be restricted cash because these funds are available only to finance (or reimburse payment of) approved expenditures; however, as of December 31, 2024, such funds were released.
Property, plant and equipment	Property, plant and equipment are reported at cost. Self-constructed electric utility plant includes engineering, supervision, administrative and general costs and an allowance for the cost of funds used during the construction period. These costs are recorded in construction in progress and are transferred to utility plant when construction is completed and the facilities are either placed in service or become useful for public utility purposes. Costs for betterments that make utility plant more useful, more efficient, of greater durability or of greater capacity are also capitalized. Upon the retirement or sale of electric utility plant, generally no gain or loss is recognized. The cost of the plant retired is charged to accumulated depreciation. Amounts collected from customers for cost of removal are included in regulatory liabilities.
Depreciation	Depreciation is computed primarily using the straight-line method over the estimated lives of the assets being depreciated. Electric utility plant additions in the current year are depreciated beginning January 1 of the following year in accordance with rate-making. Electric utility plant and Pacific Current generation assets have lives ranging from 16 to 51 years for production plant, from 10 to 79 years for transmission and distribution plant, and from 5 to 50 years for general plant.
Retirement benefits	Pension and other postretirement benefit costs are charged primarily to expense and electric utility plant (in the case of the Utilities). Funding for the Company’s qualified pension plan (Plan) is based on actuarial assumptions adopted by the Pension Investment Committee administering the Plan. The participating employers contribute amounts to pension trust for the Plan in accordance with the funding requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA), including changes promulgated by the Pension Protection Act of 2006, and considering the deductibility of contributions under the Internal Revenue Code. The Company generally funds at least the net periodic pension cost during the year, subject to ERISA minimum and Internal Revenue Code limits and targeted funded status. Certain health care and/or life insurance benefits are provided to eligible retired employees and the employees’ beneficiaries and covered dependents. The Company generally funds the net periodic postretirement benefit costs other than pension (except for executive life) for postretirement benefits other than pension (OPEB), while maximizing the use of the most tax-advantaged funding vehicles, subject to cash flow requirements and reviews of the funded status with the consulting actuary.
Environmental expenditures	The Company and the Utilities are subject to numerous federal and state environmental statutes and regulations. In general, environmental contamination treatment costs are charged to expense. Environmental costs are capitalized if the costs extend the life, increase the capacity, or improve the safety or efficiency of property; the costs mitigate or prevent future environmental contamination; or the costs are incurred in preparing the property for sale. Environmental costs are either capitalized or charged to expense when environmental assessments and/or remedial efforts are probable and the cost can be reasonably estimated. The Utilities review their sites and measure the liability quarterly by assessing a range of reasonably likely costs of each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties.
Contingencies and litigation	The Company and the Utilities are subject to proceedings (including PUC proceedings), lawsuits and other claims. Management assesses the likelihood of any adverse judgments in or outcomes of these matters as well as potential ranges of probable losses. A determination of the amount of reserves required, if any, for these contingencies is based on an analysis of each individual case or proceeding often with the assistance of outside counsel. Loss contingencies are reviewed quarterly and estimates are adjusted to reflect the impact of all known information, such as new developments in each matter or changes in approach in dealing with these matters, including changes in settlement strategy. When a loss is probable and reasonably estimable, a liability is recorded in the amount of the estimable loss. If it is reasonably possible that a loss may have been incurred and the effect on the financial statements could be material, the Company and the Utilities disclose the nature of the loss contingency and an estimate of the possible loss or range of loss or a statement that such an estimate cannot be made within the notes to the financial statements.
Income taxes	Deferred income tax assets and liabilities are established for the temporary differences between the financial reporting bases and the tax bases of the Company’s and the Utilities’ assets and liabilities at federal and state tax rates expected to be in effect when such deferred tax assets or liabilities are realized or settled. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount expected to be realized. HEI and the Utilities’ investment tax credits are deferred and amortized over the estimated useful lives of the properties to which the credits relate (and for the Utilities, this treatment is in accordance with Accounting Standards Codification (ASC) Topic 980, “Regulated Operations”). The Utilities are included in the consolidated income tax returns of HEI. However, income tax expense has been computed for financial statement purposes as if each utility filed a separate income tax return and Hawaiian Electric filed a consolidated Hawaiian Electric income tax return. Governmental tax authorities could challenge a tax return position taken by the Company. The Company and the Utilities use a “more-likely-than-not” recognition threshold and measurement standard for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return.
Fair value measurements	Fair value estimates are estimates of the price that would be received to sell an asset, or paid upon the transfer of a liability, in an orderly transaction between market participants at the measurement date. The fair value estimates are generally determined based on assumptions that market participants would use in pricing the asset or liability and are based on market data obtained from independent sources. However, in certain cases, the Company and the Utilities use their own assumptions about market participant assumptions based on the best information available in the circumstances. These valuations are estimates at a specific point in time, based on relevant market information, information about the financial instrument and judgments regarding future expected loss experience, economic conditions, risk characteristics of various financial instruments and other factors. These estimates do not reflect any premium or discount that could result if the Company or the Utilities were to sell its entire holdings of a particular financial instrument at one time. Because no active trading market exists for a portion of the Company’s and the Utilities’ financial instruments, fair value estimates cannot be determined with precision. Changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the estimates. In addition, the tax ramifications related to the realization of the unrealized gains and losses could have a significant effect on fair value estimates, but have not been considered in making such estimates. The Company and the Utilities group their financial assets measured at fair value in three levels outlined as follows: Level 1: Inputs to the valuation methodology are quoted prices, unadjusted, for identical assets or liabilities in active markets. A quoted price in an active market provides the most reliable evidence of fair value and is used to measure fair value whenever available. Level 2: Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets; inputs to the valuation methodology include quoted prices for identical or similar assets or liabilities in markets that are not active; or inputs to the valuation methodology that are derived principally from or can be corroborated by observable market data by correlation or other means. Level 3: Inputs to the valuation methodology are unobservable and significant to the fair value measurement. Level 3 assets and liabilities include financial instruments whose value is determined using discounted cash flow methodologies, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Classification in the hierarchy is based upon the lowest level input that is significant to the fair value measurement of the asset or liability. For instruments classified in Level 1 and 2 where inputs are primarily based upon observable market data, there is less judgment applied in arriving at the fair value. For instruments classified in Level 3, management judgment is more significant due to the lack of observable market data. The Company reviews and updates the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in fair value measurements may result in a reclassification between the fair value hierarchy levels and are recognized based on period-end balances. Fair value is also used on a nonrecurring basis to evaluate certain assets for impairment or for disclosure purposes. Examples of nonrecurring uses of fair value include asset retirement obligations (AROs). Fair value measurement and disclosure valuation methodology. The following are descriptions of the valuation methodologies used for assets and liabilities recorded at fair value and for estimating fair value for financial instruments not carried at fair value: Money market mutual funds. The Company considers all liquid investments purchased with an initial maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value due to the short-term nature of these instruments. Short-term borrowings. The carrying amount of short-term borrowings approximated fair value because of the short maturity of these instruments. Long-term debt. Fair value of fixed-rate long-term debt was obtained from third-party financial services providers based on the current rates offered for debt of the same or similar remaining maturities and from discounting the future cash flows using the current rates offered for debt of the same or similar risks, terms, and remaining maturities. The carrying amount of floating rate long-term debt approximated fair value because of the short-term interest reset periods. Long-term debt is classified in Level 2 of the valuation hierarchy. Interest rate swaps. The Company measures its interest rate swaps at fair value. The fair values of the Company's interest rate swaps are based on the estimated amounts that the Company would receive or pay to terminate the contracts at the reporting date and are determined using interest rate pricing models and interest rate related observable inputs. The fair values of the Company's interest rate swaps are classified as a Level 2 measurements.
Earnings per share (HEI only)	Basic earnings per share (EPS) and Basic EPS from continuing operations are computed by dividing net income for common stock and income from continuing operations for common stock, respectively, by the weighted-average number of common shares outstanding for the period. Diluted EPS and diluted EPS from continuing operations are computed similarly, except that dilutive common shares for stock compensation is added to the denominator.
Impairment of long-lived assets and long-lived assets to be disposed of	The Company and the Utilities review long-lived assets and certain identifiable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. When the Utilities conclude that recovery of the remaining carrying amount of long-lived generation asset upon retirement is probable of recovery in future rates the carrying amount of the long-lived generation asset is recorded as a regulatory asset. Other assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.
Recent accounting pronouncements	Segment Reporting. In November 2023, the FASB issued Accounting Standards Update (ASU) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures to improve reportable segment disclosure requirements, primarily through enhanced disclosure requirements of significant segment expenses. These amendments are effective for annual periods beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. These amendments apply on a retrospective basis. The Company adopted this amendment as of December 31, 2024, which did not have a material impact on its disclosures. Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvement to Income Tax Disclosures to enhance the transparency and decision usefulness of income tax disclosures. The amendments are effective for annual periods beginning after December 15, 2024. These amendments apply on a prospective basis with a retrospective option. Early adoption is permitted. The Company is currently evaluating the impact of this amendment on the Company’s consolidated financial statements and does not expect the adoption to have a material impact on its consolidated financial statements. Climate-related disclosures. In March 2024, the SEC issued final climate-related disclosure rules under SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors (climate disclosure rules). The rules will require annual disclosure of material greenhouse gas emissions as well as disclosure of governance, risk management and strategy related to material climate-related risks. In addition, the rules require (i) financial statement impacts of severe weather events and other natural conditions; (ii) a roll forward of carbon offset and renewable energy credit balances if material to the Company’s plan to achieve climate-related targets or goals; and (iii) material impacts on estimates and assumptions in the financial statements. The disclosure requirements will begin phasing in for annual periods beginning with calendar year 2025. In April 2024, the SEC voluntarily stayed implementation of its climate disclosure rules pending completion of judicial review by the Court of Appeals for the Eighth Circuit. The Company is currently monitoring developments with this final rule and evaluating its impact on the Company’s consolidated financial statements.
Reclassifications	Certain prior year amounts on the Consolidated Balance Sheet have been reclassified to conform to a classified balance sheet presentation. These prior year reclassifications include presenting current and noncurrent assets and liabilities. These reclassifications did not affect net income or shareholders’ equity for the years ended December 31, 2023. Within the consolidated balance sheet for the prior period, wildfire tort-related claims amounts were reclassified from “Other current liabilities” to current “Wildfire tort-related claims” for the Company and the Utilities, and other postretirement benefit plan asset was reclassified from noncurrent “Other asset” to noncurrent “Defined benefit pension and other postretirement benefit plans asset” for the Utilities, to conform to the current year financial statement presentation. Also, consolidated statements of cash flows of prior year wildfire tort-related claims amounts were reclassified from “Change in other assets and liabilities” to “Increase in wildfire tort-related claims” for the Company and the Utilities to conform to the current year financial statement presentation. Reclassifications did not affect previously reported net income, retained earnings or net cash provided by operating activities.
Electric utility
Regulation by the Public Utilities Commission of the State of Hawaii (PUC)	The Utilities are regulated by the PUC and account for the effects of regulation under FASB ASC Topic 980, “Regulated Operations.” As a result, the Utilities’ financial statements reflect assets, liabilities, revenues and expenses based on current cost-based rate-making regulations (see Note 4—“Regulatory assets and liabilities”). Their continued accounting under ASC Topic 980 generally requires that rates are established by an independent, third-party regulator; rates are designed to recover the costs of providing service; and it is reasonable to assume that rates can be charged to, and collected from, customers. Management believes that the operations of the Utilities, including the impact of the approved PBR Framework, currently satisfy the criteria under ASC Topic 980. The rate schedules of the Utilities include energy costs recovery clauses (ECRCs) under which electric rates are adjusted for changes in the weighted-average price paid for fuel oil and certain components of purchased power, and the relative amounts of company-generated power and purchased power. The rate schedules also include purchased power adjustment clauses (PPACs) under which the remaining purchase power expenses are recovered through surcharge mechanisms. The amounts collected through the ECRCs and PPACs are required to be reconciled quarterly.
Accounts receivable	Accounts receivable are recorded at the invoiced amount. The Utilities generally assess a late payment charge on balances unpaid from the previous month. The allowance for doubtful accounts is the Utilities’ best estimate of the amount of expected credit losses in the Utilities’ existing accounts receivable.
Electric utility revenues	Revenues related to electric service are generally recorded when service is rendered and include revenues applicable to energy consumed in the accounting period but not yet billed to the customers. The Utilities also record revenue under a decoupling mechanism.
Repairs and maintenance costs	Repairs and maintenance costs for overhauls of generating units are generally expensed as they are incurred.
Allowance for funds used during construction (AFUDC)	AFUDC represents the estimated costs of debt (i.e., interest) and equity funds used to finance plant construction. AFUDC is credited on the statement of income and charged to construction in progress on the balance sheet. If a project under construction is delayed for an extended period of time, AFUDC on the delayed project may be stopped after assessing the causes of the delay and probability of recovery. The tax gross up of the allowance for equity funds used during construction is credited to income taxes on the statement of income and charged to a regulatory asset. This gross up, net of amortization of the regulatory asset, is reflected in income tax expense.
Asset retirement obligations (AROs)	AROs are accounted for in accordance with ASC 410-20, “Asset Retirement Obligations.” AROs are recognized at present value of expected costs to retire long-lived assets from service, provided a legal obligation exists and a reasonable estimate of the fair value and the settlement date can be made. In the subsequent period, the liability is accreted to its future value while the asset retirement cost is depreciated over the estimated useful life of the underlying asset. The Utilities’ recognition of AROs have no impact on earnings, as the cost of the AROs are recovered over the life of the asset through depreciation. AROs recognized by the Utilities relate to legal obligations with the retirement of plant and equipment, including removal of asbestos and other hazardous materials.
Revenues	Revenue from contracts with customers. The revenues subject to ASC Topic 606 include the Utilities’ electric energy sales revenue as further described below. Electric Utilities. Electric energy sales. Electric energy sales represent revenues from the generation and transmission of electricity to customers under tariffs approved by the PUC. Transaction pricing for electricity is determined and approved by the PUC for each rate class and includes revenues from the base electric charges, which are composed of (1) the customer, demand, energy, and minimum charges, and (2) the power factor, service voltage, and other adjustments as provided in each rate and rate rider schedule. Electric energy sales also represent contract rate charge from the generation and transmission of electricity to the Army. The monthly pricing is recalculated on an annual basis based on actual costs, approved by the Army. The Utilities satisfy performance obligations of electric energy sales over time, i.e., the Utilities generate and transfer control of the electricity over time as the customer simultaneously receives and consumes the benefits provided by the Utilities’ performance. Payments from customers are generally due within 30 days from the end of the billing period. As electric bills to customers reflect the amount that corresponds directly with the value of the Utilities’ performance to date, the Utilities have elected to use the right to invoice practical expedient, which entitles them to recognize revenue in the amount they have the right to invoice. The Utilities’ revenues include amounts for recovery of various Hawaii state revenue taxes. Revenue taxes are generally recorded as an expense in the year the related revenues are recognized. All Other. All Other sales. Other sales primarily consist of revenues from the generation and sale of renewable energy at fixed contractual prices per kWh to customers under power purchase agreements by Pacific Current subsidiaries. The performance obligation is satisfied over time as renewable energy is generated and control is transferred to the customer that simultaneously receives and consumes the benefits provided. Payments from customers are generally due within 30 days from the end of the billing period. The bill to customers reflects the amount that corresponds directly with the value of performance to date. Pacific Current has elected to use the right to invoice practical expedient, which entitles it to recognize revenue in the amount they have the right to invoice.
Revenues from other sources	Revenues from other sources. Revenues from other sources not subject to ASC Topic 606 are accounted for as follows: Electric Utilities. Regulatory revenues. Regulatory revenues primarily consist of revenues from the decoupling mechanism and cost recovery surcharges. Decoupling mechanism - Under the current decoupling mechanism, the Utilities are allowed to recover or obligated to refund the difference between actual revenue and the target revenue as determined by the PUC, collect annual revenue adjustment mechanism (ARA) and exceptional project recovery mechanism revenues, and recover or refund performance incentive mechanism penalties or rewards. These adjustments will be reflected in tariffs in future periods. Under the PBR framework, the accrued RBA revenues as of the preceding September 30 balance and the annual ARA amount are billed from January 1 through December 31 of each year, which is within 24 months following the end of the year in which they are recorded as required by the accounting standard for alternative revenue programs (see “Regulatory proceedings” in Note 4). Cost recovery surcharges - For the timely recovery of additional costs incurred, and reconciliation of costs and expenses included in tariffed rates, the Utilities recognize revenues under surcharge mechanisms approved by the PUC. These will be reflected in tariffs in future periods (e.g., ECRC and PPAC). Since revenue adjustments discussed above resulted from either agreements with the PUC or change in tax law, rather than contracts with customers, they are not subject to the scope of ASC Topic 606. Also, see Notes 1, 4 and 13 of the Consolidated Financial Statements. The Utilities have elected to present these revenue adjustments on a gross basis, which results in the amounts being billed to customers presented in revenues from contracts with customers and the amortization of the related regulatory asset/liability as revenues from other sources. Depending on whether the previous deferral balance being amortized was a regulatory asset or regulatory liability, and depending on the size and direction of the current year deferral of surcharges and/or refunds to customers, it could result in negative regulatory revenue during the year. Utility pole attachment fees. These fees primarily represent revenues from third-party companies for their access to and shared use of Utilities-owned poles through licensing agreements. As the shared portion of the utility pole is functionally dependent on the rest of the structure, no distinct goods appear to exist. Therefore, these fees are not subject to the scope of ASC Topic 606, but recognized in accordance with ASC Topic 610, Other Income. Army privatization extraordinary O&M (EOM) fees. The monthly EOM fee provides the recovery of the incremental extraordinary O&M costs not covered under the standard utility services. The nature of the work related to transitional period revenue and monthly EOM fees do not represent the Utilities’ ongoing major or central operations (i.e., generating, and transmission and distribution of electricity) and is provided specifically for the arrangement between the Utilities and the Army. Therefore, these revenues are not subject to the scope of ASC Topic 606, but recognized in accordance with ASC Topic 610, Other Income.

Summary of significant accounting policies (Policies)

12 Months Ended

Dec. 31, 2024

In preparing the consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP), management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results could differ significantly from those estimates.

Use of estimates

Material estimates that are particularly susceptible to significant change for HEI and its subsidiaries (collectively, the Company) include the amounts reported as fair value for pension and other postretirement benefit obligations; contingencies and litigation; income taxes; regulatory assets and liabilities (Utilities only); and asset retirement obligations (Utilities only).

Consolidation

The HEI consolidated financial statements include the accounts of HEI and its subsidiaries. The Hawaiian Electric consolidated financial statements include the accounts of Hawaiian Electric and its subsidiaries. When HEI or Hawaiian Electric has a controlling financial interest in another entity (usually, majority voting interest), that entity is consolidated. Investments in companies over which the Company or the Utilities have the ability to exercise significant influence, but not control, are accounted for using the equity method. The consolidated financial statements exclude variable interest entities (VIEs) when the Company or the Utilities are not the primary beneficiaries. Significant intercompany amounts are eliminated in consolidation

Cash and cash equivalents

The Company considers cash on hand, deposits in banks, money market accounts, certificates of deposit, short-term commercial paper of non-affiliates and liquid investments (with original maturities of three months or less) to be cash and cash equivalents.

Restricted cash

The Company considers cash held by trustees, related to non-recourse loans at Pacific Current subsidiaries, and cash held by GLST1, related to the first liability installment payment pursuant to the settlement agreements to settle the tort-related legal claims in the litigation arising out of the Maui windstorm and wildfires, to be restricted cash. In addition, the Utilities consider funds on deposit with Wells Fargo, which represent collateral to secure company purchasing cards, to be restricted cash because these funds are available only to finance (or reimburse payment of) approved expenditures; however, as of December 31, 2024, such funds were released.

Property, plant and equipment

Property, plant and equipment are reported at cost. Self-constructed electric utility plant includes engineering, supervision, administrative and general costs and an allowance for the cost of funds used during the construction period. These costs are recorded in construction in progress and are transferred to utility plant when construction is completed and the facilities are either placed in service or become useful for public utility purposes. Costs for betterments that make utility plant more useful, more efficient, of greater durability or of greater capacity are also capitalized. Upon the retirement or sale of electric utility plant, generally no gain or loss is recognized. The cost of the plant retired is charged to accumulated depreciation. Amounts collected from customers for cost of removal are included in regulatory liabilities.

Depreciation

Depreciation is computed primarily using the straight-line method over the estimated lives of the assets being depreciated. Electric utility plant additions in the current year are depreciated beginning January 1 of the following year in accordance with rate-making. Electric utility plant and Pacific Current generation assets have lives ranging from 16 to 51 years for production plant, from 10 to 79 years for transmission and distribution plant, and from 5 to 50 years for general plant.

Retirement benefits

Pension and other postretirement benefit costs are charged primarily to expense and electric utility plant (in the case of the Utilities). Funding for the Company’s qualified pension plan (Plan) is based on actuarial assumptions adopted by the Pension Investment Committee administering the Plan. The participating employers contribute amounts to pension trust for the Plan in accordance with the funding requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA), including changes promulgated by the Pension Protection Act of 2006, and considering the deductibility of contributions under the Internal Revenue Code. The Company generally funds at least the net periodic pension cost during the year, subject to ERISA minimum and Internal Revenue Code limits and targeted funded status.

Certain health care and/or life insurance benefits are provided to eligible retired employees and the employees’ beneficiaries and covered dependents. The Company generally funds the net periodic postretirement benefit costs other than pension (except for executive life) for postretirement benefits other than pension (OPEB), while maximizing the use of the most tax-advantaged funding vehicles, subject to cash flow requirements and reviews of the funded status with the consulting actuary.

Environmental expenditures

The Company and the Utilities are subject to numerous federal and state environmental statutes and regulations. In general, environmental contamination treatment costs are charged to expense. Environmental costs are capitalized if the costs extend the life, increase the capacity, or improve the safety or efficiency of property; the costs mitigate or prevent future environmental contamination; or the costs are incurred in preparing the property for sale. Environmental costs are either capitalized or charged to expense when environmental assessments and/or remedial efforts are probable and the cost can be reasonably estimated. The Utilities review their sites and measure the liability quarterly by assessing a range of reasonably likely costs of each identified site using currently available information, including existing technology, presently enacted laws and regulations, experience gained at similar sites, and the probable level of involvement and financial condition of other potentially responsible parties.

Contingencies and litigation

The Company and the Utilities are subject to proceedings (including PUC proceedings), lawsuits and other claims. Management assesses the likelihood of any adverse judgments in or outcomes of these matters as well as potential ranges of probable losses. A determination of the amount of reserves required, if any, for these contingencies

is based on an analysis of each individual case or proceeding often with the assistance of outside counsel. Loss contingencies are reviewed quarterly and estimates are adjusted to reflect the impact of all known information, such as new developments in each matter or changes in approach in dealing with these matters, including changes in settlement strategy. When a loss is probable and reasonably estimable, a liability is recorded in the amount of the estimable loss. If it is reasonably possible that a loss may have been incurred and the effect on the financial statements could be material, the Company and the Utilities disclose the nature of the loss contingency and an estimate of the possible loss or range of loss or a statement that such an estimate cannot be made within the notes to the financial statements.

Income taxes

Deferred income tax assets and liabilities are established for the temporary differences between the financial reporting bases and the tax bases of the Company’s and the Utilities’ assets and liabilities at federal and state tax rates expected to be in effect when such deferred tax assets or liabilities are realized or settled. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Valuation allowances are established when necessary to reduce deferred income tax assets to the amount expected to be realized.

HEI and the Utilities’ investment tax credits are deferred and amortized over the estimated useful lives of the properties to which the credits relate (and for the Utilities, this treatment is in accordance with Accounting Standards Codification (ASC) Topic 980, “Regulated Operations”).

The Utilities are included in the consolidated income tax returns of HEI. However, income tax expense has been computed for financial statement purposes as if each utility filed a separate income tax return and Hawaiian Electric filed a consolidated Hawaiian Electric income tax return.

Governmental tax authorities could challenge a tax return position taken by the Company. The Company and the Utilities use a “more-likely-than-not” recognition threshold and measurement standard for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return.

Fair value measurements

Fair value estimates are estimates of the price that would be received to sell an asset, or paid upon the transfer of a liability, in an orderly transaction between market participants at the measurement date. The fair value estimates are generally determined based on assumptions that market participants would use in pricing the asset or liability and are based on market data obtained from independent sources. However, in certain cases, the Company and the Utilities use their own assumptions about market participant assumptions based on the best information available in the circumstances. These valuations are estimates at a specific point in time, based on relevant market information, information about the financial instrument and judgments regarding future expected loss experience, economic conditions, risk characteristics of various financial instruments and other factors. These estimates do not reflect any premium or discount that could result if the Company or the Utilities were to sell its entire holdings of a particular financial instrument at one time. Because no active trading market exists for a portion of the Company’s and the Utilities’ financial instruments, fair value estimates cannot be determined with precision. Changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the estimates. In addition, the tax ramifications related to the realization of the unrealized gains and losses could have a significant effect on fair value estimates, but have not been considered in making such estimates.

The Company and the Utilities group their financial assets measured at fair value in three levels outlined as follows:

Level 1: Inputs to the valuation methodology are quoted prices, unadjusted, for identical assets or liabilities in active markets. A quoted price in an active market provides the most reliable evidence of fair value and is used to measure fair value whenever available.

Level 2: Inputs to the valuation methodology include quoted prices for similar assets or liabilities in active markets; inputs to the valuation methodology include quoted prices for identical or similar assets or liabilities in markets that are not active; or inputs to the valuation methodology that are derived principally from or can be corroborated by observable market data by correlation or other means.

Level 3: Inputs to the valuation methodology are unobservable and significant to the fair value measurement. Level 3 assets and liabilities include financial instruments whose value is determined using discounted cash flow methodologies, as well as instruments for which the determination of fair value requires significant management judgment or estimation.

Classification in the hierarchy is based upon the lowest level input that is significant to the fair value measurement of the asset or liability. For instruments classified in Level 1 and 2 where inputs are primarily based upon observable market data, there is less judgment applied in arriving at the fair value. For instruments classified in Level 3, management judgment is more significant due to the lack of observable market data.

The Company reviews and updates the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in fair value measurements may result in a reclassification between the fair value hierarchy levels and are recognized based on period-end balances.

Fair value is also used on a nonrecurring basis to evaluate certain assets for impairment or for disclosure purposes. Examples of nonrecurring uses of fair value include asset retirement obligations (AROs).

Fair value measurement and disclosure valuation methodology. The following are descriptions of the valuation methodologies used for assets and liabilities recorded at fair value and for estimating fair value for financial instruments not carried at fair value:

Money market mutual funds. The Company considers all liquid investments purchased with an initial maturity of three months or less and deposits in money market mutual funds that are readily convertible into cash to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value due to the short-term nature of these instruments.

Short-term borrowings. The carrying amount of short-term borrowings approximated fair value because of the short maturity of these instruments.

Long-term debt. Fair value of fixed-rate long-term debt was obtained from third-party financial services providers based on the current rates offered for debt of the same or similar remaining maturities and from discounting the future cash flows using the current rates offered for debt of the same or similar risks, terms, and remaining maturities. The carrying amount of floating rate long-term debt approximated fair value because of the short-term interest reset periods. Long-term debt is classified in Level 2 of the valuation hierarchy.

Interest rate swaps. The Company measures its interest rate swaps at fair value. The fair values of the Company's interest rate swaps are based on the estimated amounts that the Company would receive or pay to terminate the contracts at the reporting date and are determined using interest rate pricing models and interest rate related observable inputs. The fair values of the Company's interest rate swaps are classified as a Level 2 measurements.

Earnings per share (HEI only)

Basic earnings per share (EPS) and Basic EPS from continuing operations are computed by dividing net income for common stock and income from continuing operations for common stock, respectively, by the weighted-average number of common shares outstanding for the period. Diluted EPS and diluted EPS from continuing operations are computed similarly, except that dilutive common shares for stock compensation is added to the denominator.

Impairment of long-lived assets and long-lived assets to be disposed of

The Company and the Utilities review long-lived assets and certain identifiable intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets. When the Utilities conclude that recovery of the remaining carrying amount of long-lived generation asset upon retirement is probable of recovery in future rates the carrying amount of the long-lived generation asset is recorded as a regulatory asset. Other assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.

Recent accounting pronouncements

Segment Reporting. In November 2023, the FASB issued Accounting Standards Update (ASU) No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures to improve reportable segment disclosure requirements, primarily through enhanced disclosure requirements of significant segment expenses. These amendments are effective for annual periods beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. These amendments apply on a retrospective basis. The Company adopted this amendment as of December 31, 2024, which did not have a material impact on its disclosures.

Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740): Improvement to Income Tax Disclosures to enhance the transparency and decision usefulness of income tax disclosures. The amendments are effective for annual periods beginning after December 15, 2024. These amendments apply on a prospective basis with a retrospective option. Early adoption is permitted. The Company is currently evaluating the impact of this amendment on the Company’s consolidated financial statements and does not expect the adoption to have a material impact on its consolidated financial statements.

Climate-related disclosures. In March 2024, the SEC issued final climate-related disclosure rules under SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors (climate disclosure rules). The rules will require annual disclosure of material greenhouse gas emissions as well as disclosure of governance, risk management and strategy related to material climate-related risks. In addition, the rules require (i) financial statement impacts of severe weather events and other natural conditions; (ii) a roll forward of carbon offset and renewable energy credit balances if material to the Company’s plan to achieve climate-related targets or goals; and (iii) material impacts on estimates and assumptions in the financial statements. The disclosure requirements will begin phasing in for annual periods beginning with calendar year 2025. In April 2024, the SEC voluntarily stayed implementation of its climate disclosure rules pending completion of judicial review by the Court of Appeals for the Eighth Circuit. The Company is currently monitoring developments with this final rule and evaluating its impact on the Company’s consolidated financial statements.

Reclassifications

Certain prior year amounts on the Consolidated Balance Sheet have been reclassified to conform to a classified balance sheet presentation. These prior year reclassifications include presenting current and noncurrent assets and liabilities. These reclassifications did not affect net income or shareholders’ equity for the years ended December 31, 2023.

Within the consolidated balance sheet for the prior period, wildfire tort-related claims amounts were reclassified from “Other current liabilities” to current “Wildfire tort-related claims” for the Company and the Utilities, and other postretirement benefit plan asset was reclassified from noncurrent “Other asset” to noncurrent “Defined benefit pension and other postretirement benefit plans asset” for the Utilities, to conform to the current year financial statement presentation. Also, consolidated statements of cash flows of prior year wildfire tort-related claims amounts were reclassified from “Change in other

assets and liabilities” to “Increase in wildfire tort-related claims” for the Company and the Utilities to conform to the current year financial statement presentation. Reclassifications did not affect previously reported net income, retained earnings or net cash provided by operating activities.

Electric utility

Regulation by the Public Utilities Commission of the State of Hawaii (PUC)

The Utilities are regulated by the PUC and account for the effects of regulation under FASB ASC Topic 980, “Regulated Operations.” As a result, the Utilities’ financial statements reflect assets, liabilities, revenues and expenses based on current cost-based rate-making regulations (see Note 4—“Regulatory assets and liabilities”). Their continued accounting under ASC Topic 980 generally requires that rates are established by an independent, third-party regulator; rates are designed to recover the costs of providing service; and it is reasonable to assume that rates can be charged to, and collected from, customers. Management believes that the operations of the Utilities, including the impact of the approved PBR Framework, currently satisfy the criteria under ASC Topic 980.

The rate schedules of the Utilities include energy costs recovery clauses (ECRCs) under which electric rates are adjusted for changes in the weighted-average price paid for fuel oil and certain components of purchased power, and the relative amounts of company-generated power and purchased power. The rate schedules also include purchased power adjustment clauses (PPACs) under which the remaining purchase power expenses are recovered through surcharge mechanisms. The amounts collected through the ECRCs and PPACs are required to be reconciled quarterly.

Accounts receivable

Accounts receivable are recorded at the invoiced amount. The Utilities generally assess a late payment charge on balances unpaid from the previous month. The allowance for doubtful accounts is the Utilities’ best estimate of the amount of expected credit losses in the Utilities’ existing accounts receivable.

Electric utility revenues

Revenues related to electric service are generally recorded when service is rendered and include revenues applicable to energy consumed in the accounting period but not yet billed to the customers. The Utilities also record revenue under a decoupling mechanism.

Repairs and maintenance costs

Repairs and maintenance costs for overhauls of generating units are generally expensed as they are incurred.

Allowance for funds used during construction (AFUDC)

AFUDC represents the estimated costs of debt (i.e., interest) and equity funds used to finance plant construction. AFUDC is credited on the statement of income and charged to construction in progress on the balance sheet. If a project under construction is delayed for an extended period of time, AFUDC on the delayed project may be stopped after assessing the causes of the delay and probability of recovery. The tax gross up of the allowance for equity funds used during construction is credited to income taxes on the statement of income and charged to a regulatory asset. This gross up, net of amortization of the regulatory asset, is reflected in income tax expense.

Asset retirement obligations (AROs)

AROs are accounted for in accordance with ASC 410-20, “Asset Retirement Obligations.” AROs are recognized at present value of expected costs to retire long-lived assets from service, provided a legal obligation exists and a reasonable estimate of the fair value and the settlement date can be made. In the subsequent period, the liability is accreted to its future value while the asset retirement cost is depreciated over the estimated useful life of the underlying asset. The Utilities’ recognition of AROs have no impact on earnings, as the cost of the AROs are recovered over the life of the asset through depreciation. AROs recognized by the Utilities relate to legal obligations with the retirement of plant and equipment, including removal of asbestos and other hazardous materials.

Revenues

Revenue from contracts with customers. The revenues subject to ASC Topic 606 include the Utilities’ electric energy sales revenue as further described below.

Electric Utilities.

Electric energy sales. Electric energy sales represent revenues from the generation and transmission of electricity to customers under tariffs approved by the PUC. Transaction pricing for electricity is determined and approved by the PUC for each rate class and includes revenues from the base electric charges, which are composed of (1) the customer, demand, energy, and minimum charges, and (2) the power factor, service voltage, and other adjustments as provided in each rate and rate rider schedule. Electric energy sales also represent contract rate charge from the generation and transmission of electricity to the Army. The monthly pricing is recalculated on an annual basis based on actual costs, approved by the Army.

The Utilities satisfy performance obligations of electric energy sales over time, i.e., the Utilities generate and transfer control of the electricity over time as the customer simultaneously receives and consumes the benefits provided by the Utilities’ performance. Payments from customers are generally due within 30 days from the end of the billing period. As electric bills to customers reflect the amount that corresponds directly with the value of the Utilities’ performance to date, the Utilities have elected to use the right to invoice practical expedient, which entitles them to recognize revenue in the amount they have the right to invoice.

The Utilities’ revenues include amounts for recovery of various Hawaii state revenue taxes. Revenue taxes are generally recorded as an expense in the year the related revenues are recognized.

All Other.

All Other sales. Other sales primarily consist of revenues from the generation and sale of renewable energy at fixed contractual prices per kWh to customers under power purchase agreements by Pacific Current subsidiaries. The performance obligation is satisfied over time as renewable energy is generated and control is transferred to the customer that simultaneously receives and consumes the benefits provided. Payments from customers are generally due within 30 days from the end of the billing period. The bill to customers reflects the amount that corresponds directly with the value of performance to date. Pacific Current has elected to use the right to invoice practical expedient, which entitles it to recognize revenue in the amount they have the right to invoice.

Revenues from other sources

Revenues from other sources. Revenues from other sources not subject to ASC Topic 606 are accounted for as follows:

Electric Utilities.

Regulatory revenues. Regulatory revenues primarily consist of revenues from the decoupling mechanism and cost recovery surcharges.

Decoupling mechanism - Under the current decoupling mechanism, the Utilities are allowed to recover or obligated to refund the difference between actual revenue and the target revenue as determined by the PUC, collect annual revenue adjustment mechanism (ARA) and exceptional project recovery mechanism revenues, and recover or refund performance incentive mechanism penalties or rewards. These adjustments will be reflected in tariffs in future periods. Under the PBR framework, the accrued RBA revenues as of the preceding September 30 balance and the annual ARA amount are billed from January 1 through December 31 of each year, which is within 24 months following the end of the year in which they are recorded as required by the accounting standard for alternative revenue programs (see “Regulatory proceedings” in Note 4).

Cost recovery surcharges - For the timely recovery of additional costs incurred, and reconciliation of costs and expenses included in tariffed rates, the Utilities recognize revenues under surcharge mechanisms approved by the PUC. These will be reflected in tariffs in future periods (e.g., ECRC and PPAC).

Since revenue adjustments discussed above resulted from either agreements with the PUC or change in tax law, rather than contracts with customers, they are not subject to the scope of ASC Topic 606. Also, see Notes 1, 4 and 13 of the Consolidated Financial Statements. The Utilities have elected to present these revenue adjustments on a gross basis, which results in the amounts being billed to customers presented in revenues from contracts with customers and the amortization of the related regulatory asset/liability as revenues from other sources. Depending on whether the previous deferral balance being amortized was a regulatory asset or regulatory liability, and depending on the size and direction of the current year deferral of surcharges and/or refunds to customers, it could result in negative regulatory revenue during the year.

Utility pole attachment fees. These fees primarily represent revenues from third-party companies for their access to and shared use of Utilities-owned poles through licensing agreements. As the shared portion of the utility pole is functionally dependent on the rest of the structure, no distinct goods appear to exist. Therefore, these fees are not subject to the scope of ASC Topic 606, but recognized in accordance with ASC Topic 610, Other Income.

Army privatization extraordinary O&M (EOM) fees. The monthly EOM fee provides the recovery of the incremental extraordinary O&M costs not covered under the standard utility services. The nature of the work related to transitional period revenue and monthly EOM fees do not represent the Utilities’ ongoing major or central operations (i.e., generating, and transmission and distribution of electricity) and is provided specifically for the arrangement between the Utilities and the Army. Therefore, these revenues are not subject to the scope of ASC Topic 606, but recognized in accordance with ASC Topic 610, Other Income.