PROPERTY, PLANT AND EQUIPMENT AND ACCUMULATED DEPRECIATION (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Schedule of Utility Property, Plant and Equipment

The following tables summarize property, plant and equipment by asset category:

Eversource	As of December 31,
(Millions of Dollars)	2023		2022
Distribution - Electric	$	19,656.5	$	18,326.2
Distribution - Natural Gas	8,155.3		7,443.8
Transmission - Electric	14,666.8		13,709.3
Distribution - Water	2,280.1		2,112.6
Solar	201.1		200.8
Utility	44,959.8		41,792.7
Other (1)	2,006.8		1,738.1
Property, Plant and Equipment, Gross	46,966.6		43,530.8
Less:  Accumulated Depreciation
Utility	(9,670.1)		(9,167.4)
Other	(869.6)		(706.1)
Total Accumulated Depreciation	(10,539.7)		(9,873.5)
Property, Plant and Equipment, Net	36,426.9		33,657.3
Construction Work in Progress	3,071.7		2,455.5
Total Property, Plant and Equipment, Net	$	39,498.6	$	36,112.8

	As of December 31,
	2023						2022
(Millions of Dollars)	CL&P		NSTAR Electric		PSNH		CL&P		NSTAR Electric		PSNH
Distribution - Electric	$	7,897.1	$	9,000.5	$	2,799.2	$	7,370.1	$	8,410.0	$	2,586.4
Transmission - Electric	6,548.2		5,630.8		2,489.5		6,165.1		5,333.8		2,212.0
Solar	—		201.1		—		—		200.8		—
Property, Plant and Equipment, Gross	14,445.3		14,832.4		5,288.7		13,535.2		13,944.6		4,798.4
Less:  Accumulated Depreciation	(2,670.5)		(3,585.9)		(984.0)		(2,567.1)		(3,381.2)		(912.3)
Property, Plant and Equipment, Net	11,774.8		11,246.5		4,304.7		10,968.1		10,563.4		3,886.1
Construction Work in Progress	565.4		1,507.3		270.0		498.9		1,063.6		174.1
Total Property, Plant and Equipment, Net	$	12,340.2	$	12,753.8	$	4,574.7	$	11,467.0	$	11,627.0	$	4,060.2

(1)These assets are primarily comprised of computer software, hardware and equipment at Eversource Service and buildings at The Rocky River Realty Company.

The depreciation rates for the various classes of utility property, plant and equipment aggregate to composite rates as follows:

(Percent)	2023		2022		2021
Eversource	3.1	%	3.0	%	3.1	%
CL&P	2.8	%	2.8	%	2.8	%
NSTAR Electric	2.7	%	2.7	%	2.8	%
PSNH	3.0	%	3.0	%	3.1	%

The following table summarizes average remaining useful lives of depreciable assets:

	As of December 31, 2023
(Years)	Eversource	CL&P	NSTAR Electric	PSNH
Distribution - Electric	34.0	35.3	34.5	29.6
Distribution - Natural Gas	35.7	—	—	—
Transmission - Electric	40.6	37.1	45.3	41.4
Distribution - Water	40.0	—	—	—
Solar	22.8	—	22.8	—
Other (1)	10.4	—	—	—

(1)The estimated useful life of computer software, hardware and equipment primarily ranges from 5 to 15 years and of buildings is 40 years.