|3 Months Ended
Mar. 31, 2022
|Revenue from Contract with Customer [Abstract]
NOTE 5 – Revenues
Revenue by Product Type
The following table disaggregates revenue by significant product type for the three months ended March 31, 2022 and 2021:
Contract Assets and Contract Liabilities
The timing of revenue recognition may differ from the timing of invoicing to customers. Contract assets include unbilled amounts from equipment sales projects when revenues recognized under the cost-to-cost measure of progress exceed the amounts invoiced to customers, as the amounts cannot be billed under the terms of the contracts. There were no credit allowances for contract assets as of March 31, 2022 or December 31, 2021. Contract liabilities from contracts arise when amounts invoiced to customers exceed revenues from equipment sales recognized under the cost-to-cost measure of progress. Contract liabilities additionally include advanced payments from customers on certain equipment contracts. Contract liabilities decrease as revenue is recognized from the satisfaction of the related performance obligation and are recorded as either current or long-term, depending upon when such revenue is expected to be recognized.
Contract assets and liabilities consisted of the following as of March 31, 2022 and December 31, 2021:
The change in contract liabilities during three months ended March 31, 2022 was primarily due to an increase in new equipment sales billings in advance of revenue recognition, partially offset by $82 thousand of revenue recognized that was included in contract liabilities at December 31, 2021.
Transaction Price Allocated to Remaining Unsatisfied Performance Obligations
Remaining unsatisfied performance obligations as of March 31, 2022 relate to certain of the Company’s RNG and Environmental Attributes contracts. The Company applies the optional exemptions in ASC 606 and does not disclose consideration for remaining performance obligations with an original expected duration of one year or less or for variable consideration related to unsatisfied performance obligations. Firm contracts for fixed-price, fixed-quantity sales of RNG and Environmental Attributes based on minimum contractual volumes are reflected in the table below when their original expected term is in excess of one year. The following table summarizes the revenue the Company expects to recognize over next 20 years on these firm sales contracts as of March 31, 2022: