| Disaggregation of Revenue [Table Text Block] |
| | | | Year Ended | |
| | Reportable | | March 31, | |
| | Segment | | 2026 | | | 2025 | | | 2024 | |
| Region: | | | | | | | | | | | | | |
| North America | Grid | | $ | 174,103 | | | $ | 169,104 | | | $ | 104,423 | |
| South America | Grid | | | 23,819 | | | | 782 | | | | 2,613 | |
| Asia Pacific | Grid | | | 41,050 | | | | 7,392 | | | | 9,768 | |
| EMEA | Grid | | | 12,345 | | | | 9,892 | | | | 5,261 | |
| Total | Grid | | $ | 251,317 | | | $ | 187,170 | | | $ | 122,065 | |
| | | | | | | | | | | | | | |
| Region: | | | | | | | | | | | | | |
| North America | Wind | | $ | 16 | | | $ | 2 | | | $ | 102 | |
| South America | Wind | | | — | | | | — | | | | — | |
| Asia Pacific | Wind | | | 47,668 | | | | 35,608 | | | | 23,404 | |
| EMEA | Wind | | | 154 | | | | 38 | | | | 68 | |
| Total | | $ | 47,838 | | | $ | 35,648 | | | $ | 23,574 | |
|
| Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] |
| | | Unbilled AR | | | Deferred Program Costs | | | Contract Liabilities | |
| Beginning balance as of March 31, 2025 | | $ | 6,376 | | | $ | 5,756 | | | $ | 76,133 | |
| Increases for balances acquired | | | — | | | | — | | | | 19,783 | |
| Increases for costs incurred to fulfill performance obligations | | | — | | | | 38,803 | | | | — | |
| Increase (decrease) due to customer billings | | | (22,332 | ) | | | — | | | | 114,307 | |
| Decrease due to cost recognition on completed performance obligations | | | — | | | | (37,022 | ) | | | — | |
| Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations | | | 30,868 | | | | — | | | | (117,899 | ) |
| Other changes and foreign currency exchange impact | | | (37 | ) | | | 42 | | | | 1,007 | |
| Ending balance as of March 31, 2026 | | $ | 14,875 | | | $ | 7,579 | | | $ | 93,331 | |
| | | Unbilled AR | | | Deferred Program Costs | | | Contract Liabilities | |
| Beginning balance as of March 31, 2024 | | $ | 6,150 | | | $ | 2,523 | | | $ | 57,829 | |
| Increases for balances acquired | | | — | | | | — | | | | 5,049 | |
| Increases for costs incurred to fulfill performance obligations | | | — | | | | 16,363 | | | | — | |
| Increase (decrease) due to customer billings | | | (8,754 | ) | | | — | | | | 120,533 | |
| Decrease due to cost recognition on completed performance obligations | | | — | | | | (13,131 | ) | | | — | |
| Increase (decrease) due to recognition of revenue based on transfer of control of performance obligations | | | 8,981 | | | | — | | | | (107,211 | ) |
| Other changes and foreign currency exchange impact | | | (1 | ) | | | 1 | | | | (67 | ) |
| Ending balance as of March 31, 2025 | | $ | 6,376 | | | $ | 5,756 | | | $ | 76,133 | |
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