REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	$ 19,887	$ 17,608
Revenue accounted for under other guidance	19	5
Total revenue	19,906	17,613
Product revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	12,748	13,666
Revenue accounted for under other guidance	19	5
Total revenue	12,767	13,671
Service revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	7,139	3,942
Revenue accounted for under other guidance	0	0
Total revenue	7,139	3,942
Lighting product and installation
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	12,719	12,616
Lighting product and installation | Product revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	10,045	11,785
Lighting product and installation | Service revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	2,674	831
Maintenance services
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	3,323	3,754
Maintenance services | Product revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	1,000	899
Maintenance services | Service revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	2,323	2,855
Electric vehicle charging
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	3,830	1,238
Electric vehicle charging | Product revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	1,688	982
Electric vehicle charging | Service revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	2,142	$ 256
Solar energy related revenues
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	15
Solar energy related revenues | Product revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	15
Solar energy related revenues | Service revenue
Disaggregation Of Revenue [Line Items]
Total revenues from contracts with customers	$ 0