Use of Estimates, Policy [Policy Text Block]

Use of Estimates. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and revenues and expenses during the reporting period. To the extent there are material differences between these estimates and actual results, the Company’s consolidated financial statements will be affected.

Cost of Goods and Service [Policy Text Block]

Cost of Goods Sold. Cost of goods sold includes those costs directly associated with the production of revenues, such as raw material consumed, factory overhead, and other direct production costs. During periods of idle plant capacity from January to May 2023, costs otherwise charged to cost of goods sold are reclassified to selling, general and administrative expense.

Research and Development Expense, Policy [Policy Text Block]

Research and Development. Research and development costs are expensed as incurred, unless they have alternative future uses to the Company.

Receivable [Policy Text Block]

Accounts Receivable. The Company sells all of its products to J.D. Heiskell under the J.D. Heiskell Purchasing Agreement. Our third-party marketing partners arrange to buy ethanol and WDG generally without requiring collateral and sell directly to customers on a variety of terms including advanced payment terms, based on the size and creditworthiness of the customer. DCO and CDS are marketed and sold to various customers under the J.D. Heiskell Purchasing Agreement. The Company sells biodiesel, glycerin, and processed natural oils to a variety of customers and may require advanced payment based on the size and creditworthiness of the customer. Usually, invoices are due within 30 days on net terms. Accounts receivable mostly consist of product sales made to large creditworthy customers. Trade accounts receivable are presented at original invoice amount, net of any allowance for doubtful accounts.

The Company maintains an allowance for doubtful accounts for balances that appear to have specific collection issues and estimates an allowance for expected credit losses. The collection process is based on the age of the invoice and requires attempted contacts with the customer at specified intervals. If, after a specified number of days, the Company has been unsuccessful in its collection efforts, a bad debt allowance is recorded for the balance in question. Delinquent accounts receivables are charged against the allowance for doubtful accounts once un-collectability has been determined. The factors considered in reaching this determination are the apparent financial condition of the customer and the Company’s success in contacting and negotiating with the customer. If the financial condition of the Company’s customers were to deteriorate, additional allowances may be required.

Other Current Assets Policy [Policy Text Block]

Other current assets. The other current assets contain input tax credits of $1.6 million, employee advance receivables of $69 thousand, and advances to customers of $1.2 million by our India biodiesel segment.

Property, Plant and Equipment, Policy [Policy Text Block]

Property, Plant and Equipment. Property, plant, and equipment are carried at cost less accumulated depreciation after assets are placed in service and are comprised primarily of buildings, furniture, machinery, equipment, land, biogas dairy digesters, and the Keyes Plant, Goodland Plant and Kakinada Plant. It is the Company’s policy to depreciate capital assets over their estimated useful lives using the straight-line method.

The Company evaluates the recoverability of long-lived assets with finite lives in accordance with ASC Subtopic 360-10-35 Property Plant and Equipment –Subsequent Measurement, which requires recognition of impairment of long-lived assets whenever events or changes in circumstances indicate that the carrying amount of asset groups may not be recoverable. When events or changes in circumstances indicate that the carrying amount of an asset group may not be recoverable, based on estimated undiscounted cash flows, the impairment loss would be measured as the difference between the carrying amount of the asset group and its estimated fair value. The Company has not recorded any impairment as of December 31, 2023 and 2022.

Regulatory Income Taxes, Policy [Policy Text Block]

Investment Tax Credits. In the third quarter of 2023, the Company sold to a third-party purchaser certain transferrable Investment Tax Credits (ITCs) that had been generated by the Company from its investments in the California Dairy Renewable Natural Gas segment. The Company accounted for the ITC sale in accordance with ASC 740 by electing the flow-through method. The net value of the tax credits sale of $55.2 million is recorded as an income tax benefit in the income statement for the period ending December 31, 2023. The cash was received in October 2023, and it was used to make certain principal and interest payments on revolving notes and Series A preferred financing.

Earnings Per Share, Policy [Policy Text Block]

Basic and Diluted Net Income (Loss) per Share. Basic net loss per share is computed by dividing net income or loss attributable to common shareholders by the weighted average number of common shares outstanding for the period. Diluted net loss per share reflects the dilution of common stock equivalents such as options, convertible preferred stock, debt and warrants to the extent the impact is dilutive. As the Company incurred a net loss for the years ended December 31, 2023 and 2022, potentially dilutive securities have been excluded from the diluted net loss per share computations as their effect would be anti-dilutive.

The following table shows the number of potentially dilutive shares excluded from the diluted net loss per share calculation as of December 31, 2023 and 2022:

	*As of*
	*December 31, 2023*		*December 31, 2022*

Series B preferred (post split basis)		-		127
Common stock options and warrants		6,056		5,050
Debt with conversion feature at $30 per share of common stock		1,267		1,240
Total number of potentially dilutive shares excluded from the diluted net (loss) per share calculation		7,323		6,417

Foreign Currency Transactions and Translations Policy [Policy Text Block]

Foreign Currency Translation/Transactions. The Company’s India subsidiary operates in a local currency environment where the local currency is the functional currency used for transactions and accounting. Assets and liabilities of that subsidiary are translated into U.S. dollars at exchange rates in effect at the balance sheet date and the resulting translation adjustments directly recorded to a separate component of accumulated other comprehensive loss. Income and expense accounts are translated at average exchange rates during the year. Transactional gains and losses from foreign currency transactions are recorded in other (income) loss, net.

Share-Based Payment Arrangement [Policy Text Block]

Share Based Compensation. We recognize share-based compensation expense in accordance with ASC 718 Stock Compensation, which requires the Company to recognize expenses related to the estimated fair value of the Company’s share-based compensation awards over the vesting period, adjusted to reflect only those shares that are expected to vest.

Debt, Policy [Policy Text Block]

Convertible Instruments. The Company evaluates the impacts of convertible instruments based on the underlying conversion features. Convertible Instruments are evaluated for treatment as derivatives that could be bifurcated and recorded separately.

Debt Issuance Costs. The Company records debt issuance costs related to specific incremental costs directly attributable to issuing, modifying, or extending a debt instrument. The debt issuance costs are reported as an adjustment to the carrying amount of the debt. The debt issuance costs are amortized using the interest rate method over the life of the debt instrument.

Troubled Debt Restructuring Accounting. The evaluation for troubled debt restructuring includes assessing whether the creditor granted a concession. To determine this, we calculate the post-restructuring effective interest rate by projecting cash flows on the new terms and calculating a discount rate equal to the carrying amount of pre-restructuring debt and comparing this calculation to the terms of prior amendments. If the post restructuring effective interest rate is less than the prior terms effective interest rate, we assess this as having been granted a concession. We then apply troubled debt restructuring accounting to any debt in which the creditor granted a concession.

Debt Modification Accounting. The Company evaluates amendments to its debt in accordance with ASC 540-50 Debt – Modification and Extinguishments for modification and extinguishment accounting. This evaluation includes comparing the net present value of cash flows of the new debt to the old debt to determine if changes greater than 10 percent occurred. In instances where the net present value of future cash flows changed more than 10 percent, the Company applies extinguishment accounting and determines the fair value of its debt based on factors available to the Company.