Note 1 - Summary of Significant Accounting Policies - Schedule of Regulatory Assets and Liabilities (Details) - USD ($)	Sep. 30, 2025	Sep. 30, 2024
Regulatory assets	$ 2,582,838	$ 5,103,910
Noncurrent regulatory assets	3,315,082	4,445,044
Total regulatory assets	5,897,920	9,548,954
Regulatory liabilities	1,638,911	834,278
Regulatory cost of retirement obligations	15,869,691	14,409,847
Regulatory Liability, Noncurrent	17,371,430	19,326,567
Total non-current	33,241,121	33,736,414
Total regulatory liabilities	34,880,032	34,570,692
Rate Refund [Member]
Regulatory liabilities	0	37,500
Deferred Income Tax Charge [Member]
Regulatory liabilities	591,764	591,764
Regulatory Liability, Noncurrent	13,649,719	15,468,096
Supplier Refund [Member]
Regulatory liabilities	889,564	30,556
Other Deferred Liabilities [Member]
Regulatory liabilities	157,583	174,458
Other Regulatory Assets (Liabilities) [Member]
Regulatory Liability, Noncurrent	3,721,711	3,858,471
WNA [Member]
Regulatory assets	504,003	919,375
Regulatory Clause Revenues, under-Recovered [Member]
Regulatory assets	750,295	2,690,247
Under-recovery of RNG Revenues [Member]
Regulatory assets	1,019,821	1,331,064
Under-recovery of SAVE Plan Revenues [Member]
Regulatory assets	265,317	107,678
Pension Costs [Member]
Regulatory assets	30,640	42,785
Noncurrent regulatory assets	2,168,902	2,998,881
Other Deferred Expenses [Member]
Regulatory assets	12,762	12,761
Deferred Gain (Loss) on Early Extinguishment of Debt [Member]
Noncurrent regulatory assets	1,027,684	1,141,872
Total regulatory assets	1,027,684	1,141,872
Other Assets [Member]
Noncurrent regulatory assets	$ 118,496	$ 304,291