Note 1 - Summary of Significant Accounting Policies - Schedule of Regulatory Assets and Liabilities (Details) - USD ($)	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Regulatory assets	$ 2,854,276	$ 1,877,468
Utility property in service, other	479,647	11,945
Construction work in progress - AFUDC	356,325	461,342
Noncurrent regulatory assets	5,389,445	5,446,547
Total regulatory assets	9,079,693	7,797,302
Regulatory liabilities	1,632,716	3,168,066
Asset retirement obligations	10,792,831	10,204,079	$ 7,628,958
Regulatory cost of retirement obligations	13,029,376	12,277,796
Regulatory Liability, Noncurrent	18,031,693	13,223,124
Total non-current	41,853,900	35,704,999
Total regulatory liabilities	43,486,616	38,873,065
Over-recovery of SAVE Plan Revenues [Member]
Regulatory liabilities	146,861	158,847
Rate Refund [Member]
Regulatory liabilities	652,018	0
Deferred Income Tax Charge [Member]
Regulatory liabilities	527,034	363,297
Regulatory Liability, Noncurrent	16,249,776	13,193,006
Supplier Refund [Member]
Regulatory liabilities	275,649	2,484,992
Other Deferred Liabilities [Member]
Regulatory liabilities	31,154	160,930
Other Regulatory Assets (Liabilities) [Member]
Regulatory Liability, Noncurrent	1,781,917	30,118
WNA [Member]
Regulatory assets	414,689	193,518
Regulatory Clause Revenues, under-Recovered [Member]
Regulatory assets	1,383,340	1,316,580
Under-recovery of RNG Revenues [Member]
Regulatory assets	797,804	0
Pension Costs [Member]
Regulatory assets	243,017	237,911
Noncurrent regulatory assets	3,786,265	3,894,561
Other Deferred Expenses [Member]
Regulatory assets	15,426	129,459
Deferred Gain (Loss) on Early Extinguishment of Debt [Member]
Noncurrent regulatory assets	1,256,059	1,370,246
Total regulatory assets	1,256,059	1,370,246
Other Assets [Member]
Noncurrent regulatory assets	$ 347,121	$ 181,740

The public utilities plant and equipment construction work in progress allowance for funds used during construction.

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Regulatory cost of retirement obligations not otherwise included in ARO.

+ References

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 410
-SubTopic 20
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 980
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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 405
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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