COMMITMENTS AND CONTINGENCIES (Tables)

3 Months Ended

Mar. 31, 2026

Commitments and Contingencies Disclosure [Abstract]

Schedule of Environmental Loss Contingencies by Site

The number of environmental sites and related reserves for which remediation or long-term monitoring, preliminary site work or site assessment is being performed are as follows:

	As of March 31, 2026			As of December 31, 2025
	Number of Sites	Reserve (in millions)		Number of Sites	Reserve (in millions)
Eversource	67	$	154.1	66	$	154.3
CL&P	15	15.8		15	14.9
NSTAR Electric	15	7.0		14	7.0
PSNH	8	9.2		8	9.2

Schedule of Exposure to Guarantees and Indemnifications

The following table summarizes Eversource parent's exposure to guarantees and indemnifications of its subsidiaries and affiliates to external parties, and primarily relates to its previously-owned offshore wind investments:

As of March 31, 2026
Company (Obligor)	Description	Maximum Exposure (in millions)
Revolution Wind, LLC and TurbineCo, LLC	Offshore wind construction-related purchase agreements with third-party contractors (1)	$	122.3
Eversource Investment LLC, Eversource Investment Service Company LLC and South Fork Class B Member, LLC	Offshore wind funding and indemnification obligations (2)	143.0
Eversource Investment LLC	Revolution Wind Tax Positions (3)	300.0
Eversource TEI LLC	South Fork Wind Tax Equity (4)	50.0
South Fork Wind, LLC	Power Purchase Agreement Security (5)	7.1
Various Eversource subsidiaries	Surety bonds (6)	34.1

(1)    Eversource parent issued guarantees on behalf of its previously 50 percent-owned affiliate, Revolution Wind, LLC, and on behalf of TurbineCo, LLC (successor in interest to North East Offshore, LLC (NEO)), under which Eversource parent agreed to guarantee each entity’s performance of obligations under certain construction-related purchase agreements with third-party contractors, in an aggregate amount not to exceed $682.7 million. Eversource parent’s obligations under the guarantees expire upon the earlier of (i) dates ranging between October 2027 and November 2027 and (ii) full performance of the guaranteed obligations.

(2)     Eversource parent issued guarantees on behalf of its wholly-owned subsidiary Eversource Investment LLC (EI), which held Eversource's previous investments in offshore wind-related equity method investments until sale, and on behalf of its previously 50 percent-owned affiliate, South Fork Class B Member, LLC, whereby Eversource parent will guarantee each entity’s performance of certain funding obligations of the South Fork and Revolution Wind projects. Eversource parent also guaranteed certain indemnification obligations of EI associated with third-party credit support for EI’s investment in NEO. On September 30, 2024, Eversource parent issued a guaranty on behalf of its wholly-owned subsidiary, Eversource Investment Service Company LLC, whereby Eversource parent will guarantee Eversource Investment Service Company LLC’s performance of certain indemnification obligations during the onshore construction phase of the Revolution Wind project, in an amount not to exceed $100.0 million. These guarantees will not exceed $1.62 billion and expire upon the full performance of the guaranteed obligations.

(3)    Eversource parent issued a guaranty on behalf of EI in an amount not to exceed $900 million, which was subsequently reduced to an amount not to exceed $300 million, to GIP in order to support certain tax positions related to Revolution Wind project through June 30, 2035.

(4)    Eversource parent issued a guarantee on behalf of its wholly-owned subsidiary, Eversource TEI LLC, whereby Eversource parent will guarantee Eversource TEI LLC’s performance of certain obligations, in an amount not to exceed $50.0 million, in connection with any remaining obligations under the LLC agreement. Eversource parent’s obligations expire upon the full performance of the guaranteed obligations.

(5)    Eversource parent issued a guarantee on behalf of its previously 50 percent-owned affiliate, South Fork Wind, LLC, whereby Eversource parent will guarantee South Fork Wind, LLC's performance of certain obligations, in an amount not to exceed $7.1 million, under a Power Purchase Agreement between the Long Island Power Authority and South Fork Wind, LLC (the Agreement). The guarantee expires upon the later of (i) the end of the Agreement term, January 2044, with the option to extend to January 2049 and (ii) full performance of the guaranteed obligations.

(6)    Surety bonds expire in 2026 and 2027. Expiration dates reflect termination dates, the majority of which will be renewed or extended.  Certain surety bonds contain credit ratings triggers that would require Eversource parent to post collateral in the event that the unsecured debt credit ratings of Eversource parent are downgraded.