Revenue Recognition

3 Months Ended

Mar. 31, 2022

Revenue from Contract with Customer [Abstract]

Revenue Recognition

Revenue Recognition

The Company primarily earns revenue from sales of its energy storage systems and services including installation, commissioning, and extended warranty services. Product revenues, which were recognized at a point in time, were $3,293 and $164 for the three months ended March 31, 2022 and 2021, respectively and service revenues, which were recognized over time, were $5 and $— for the three months ended March 31, 2022 and 2021, respectively.

For the three months ended March 31, 2022, we had three customers who accounted for 43.6%, 31.5% and 15.1% of the total revenue. For the three months ended March 31, 2021, we had one customer who accounted for 100% of the total revenue.

Contract assets and Contract liabilities

The following table provides information about contract assets and contract liabilities from contracts with customers. Contract assets are included in other current assets and contract liabilities are included separately on the condensed consolidated balance sheets.

	March 31, 2022		December 31, 2021
Contract assets	$	938	$	1,369
Contract liabilities	$	2,923	$	849

The Company recognizes contract assets for certain contracts in which revenue recognition performance obligations have been satisfied however, invoicing to the customer has not yet occurred. Contract liabilities primarily relate to advance consideration received from customers in advance of the Company’s satisfying performance obligations under contractual arrangements. Contract balances are reported in a net contract asset or liability position on a contract-by-contract basis at the end of each reporting period.

Contract assets decreased by $431 during the three months ended March 31, 2022 due to reclassifications to accounts receivable from billings on existing contracts. Contract liabilities increased by $2,074 during the three months ended March 31, 2022, reflecting $2,170 in customer billings, which were not recognized as revenue during the period, offset by the recognition of $96 of revenue during the three months ended March 31, 2022 that was included in the contract liability balance at the beginning of the period.

Contract liabilities increased by $750 during the three months ended March 31, 2021 due to the timing of customer invoices in relation to the timing of revenue recognized. The Company recognized $— of revenue during the three months ended March 31, 2021 that was included in the contract liability balance at the beginning of the period.

Contract liabilities of $1,763 as of March 31, 2022 are expected to be recognized within the next twelve months. $1,160 of long-term contract liabilities are expected to be recognized as revenue during 2023.