Note 3 - Notes Receivable and Advances, Net (Details) - USD ($) |
Jun. 30, 2024 |
Dec. 31, 2023 |
|---|---|---|
| Total notes receivable and advances, non-current portion, net | $ 2,658,133 | $ 980,291 |
| RenFuel K2B AB Note Receivable [Member] | ||
| Total notes receivable and advances, non-current portion, net | 1,030,000 | 0 |
| GenMat Advances [Member] | ||
| Total notes receivable and advances, non-current portion, net | 647,842 | 0 |
| Daney Ranch Sale Note Receivable [Member] | ||
| Total notes receivable and advances, non-current portion, net | $ 980,291 | $ 980,291 |