BUSINESS SEGMENTS - Summarized Financial Information Concerning Reportable Segments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) Segment	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Reporting Information [Line Items]
Net revenue from external customers	$ 234,018	$ 212,963	$ 463,780	$ 437,129
Depreciation and amortization expenses	70,030	63,800	139,808	126,152
Gross profit	56,895	61,386	129,822	140,196
Operating income	35,318	35,127	86,231	87,710
Segment assets	6,015,612	5,506,802	6,015,612	5,506,802	$ 5,666,224
Expenditures for long-lived assets	134,824	146,839	$ 327,426	250,225
Number of segment, allocation of other segment items | Segment			2
Goodwill	170,391		$ 170,391		$ 151,023
Electricity
Segment Reporting Information [Line Items]
Depreciation and amortization expenses	59,945	56,256	119,921	111,305
Expenditures for long-lived assets	34,405	106,867	205,755	199,030
Goodwill	165,800	146,400	165,800	146,400
Electricity | Accounted for Under ASC 606
Segment Reporting Information [Line Items]
Net revenue from external customers	31,400	37,500	71,500	82,300
Product
Segment Reporting Information [Line Items]
Depreciation and amortization expenses	2,955	2,780	5,849	5,653
Expenditures for long-lived assets	1,809	1,690	3,009	3,012
Goodwill	0	0	0	0
Energy Storage
Segment Reporting Information [Line Items]
Depreciation and amortization expenses	7,130	4,764	14,037	9,194
Expenditures for long-lived assets	98,610	38,282	118,662	48,183
Goodwill	4,600	4,600	4,600	4,600
Energy Storage | Accounted for Under ASC 606
Segment Reporting Information [Line Items]
Net revenue from external customers	2,500	700	6,100	1,400
Operating Segments
Segment Reporting Information [Line Items]
Net revenue from external customers	234,018	212,963	463,780	437,129
Depreciation and amortization expenses	67,809	60,078	134,102	119,281
Other cost of revenues expenses	109,314	91,499	199,856	177,652
Gross profit	56,895	61,386	129,822	140,196
Segment operating expenses (income)	21,577	26,259	43,591	52,486
Operating income	35,318	35,127	86,231	87,710
Operating Segments | Electricity
Segment Reporting Information [Line Items]
Net revenue from external customers	159,912	166,226	340,153	357,479
Depreciation and amortization expenses	58,106	52,827	114,976	105,016
Other cost of revenues expenses	63,130	57,688	126,093	122,229
Gross profit	38,676	55,711	99,084	130,234
Segment operating expenses (income)	16,705	20,297	36,270	42,139
Operating income	21,971	35,414	62,814	88,095
Segment assets	5,225,398	4,955,806	5,225,398	4,955,806
Operating Segments | Product
Segment Reporting Information [Line Items]
Net revenue from external customers	59,612	37,829	91,381	62,661
Depreciation and amortization expenses	2,632	2,467	5,203	5,030
Other cost of revenues expenses	40,486	30,195	62,599	48,786
Gross profit	16,494	5,167	23,579	8,845
Segment operating expenses (income)	6,294	4,141	9,743	6,977
Operating income	10,200	1,026	13,836	1,868
Segment assets	238,082	192,092	238,082	192,092
Operating Segments | Energy Storage
Segment Reporting Information [Line Items]
Net revenue from external customers	14,494	8,908	32,246	16,989
Depreciation and amortization expenses	7,071	4,784	13,922	9,235
Other cost of revenues expenses	5,698	3,616	11,165	6,637
Gross profit	1,725	508	7,159	1,117
Segment operating expenses (income)	(1,422)	1,821	(2,422)	3,370
Operating income	3,147	(1,313)	9,581	(2,253)
Segment assets	552,132	358,904	552,132	358,904
Operating Segments | United States
Segment Reporting Information [Line Items]
Net revenue from external customers	129,434	130,218	284,639	282,991
Operating Segments | United States | Electricity
Segment Reporting Information [Line Items]
Net revenue from external customers	111,417	119,695	245,631	263,511
Operating Segments | United States | Product
Segment Reporting Information [Line Items]
Net revenue from external customers	3,523	1,615	6,762	2,491
Operating Segments | United States | Energy Storage
Segment Reporting Information [Line Items]
Net revenue from external customers	14,494	8,908	32,246	16,989
Operating Segments | Foreign
Segment Reporting Information [Line Items]
Net revenue from external customers	104,584	82,745	179,141	154,138
Operating Segments | Foreign | Electricity
Segment Reporting Information [Line Items]
Net revenue from external customers	48,495	46,531	94,522	93,968
Operating Segments | Foreign | Product
Segment Reporting Information [Line Items]
Net revenue from external customers	56,089	36,214	84,619	60,170
Operating Segments | Foreign | Energy Storage
Segment Reporting Information [Line Items]
Net revenue from external customers	0	0	0	0
Segment Reconciling Items
Segment Reporting Information [Line Items]
Segment assets	160,178	129,664	160,178	129,664
Segment Reconciling Items | Electricity
Segment Reporting Information [Line Items]
Segment assets	160,178	129,664	160,178	129,664
Segment Reconciling Items | Product
Segment Reporting Information [Line Items]
Segment assets	0	0	0	0
Segment Reconciling Items | Energy Storage
Segment Reporting Information [Line Items]
Segment assets	$ 0	$ 0	$ 0	$ 0