Revenue (Tables)

3 Months Ended

Mar. 31, 2023

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

The following table provides information about disaggregated revenue:

	Three Months Ended
	March 31,
$ in thousands	2023		2022
Project revenue	$	816	$	1,991
Engineering services revenue	50		53
Total services revenue	866		2,044
Grant revenue	1,071		1,495
Total revenue	$	1,937	$	3,539

Schedule of Accounts, Notes, Loans and Financing Receivable

Receivables consisted of the following:

$ in thousands	March 31, 2023		December 31, 2022
Trade receivables	$	1,593	$	1,119
Grant receivables:
Unbilled	6,681		5,610
Other grant receivables	1,578		1,578
Total grant receivables	8,259		7,188
Contract assets	529		560
Other receivables	265		328
Total receivables	$	10,646	$	9,195

Contract with Customer, Contract Asset, Contract Liability, and Receivable

The following table outlines the activity related to contract assets, which is included in total receivables on our consolidated balance sheets:

$ in thousands
Balance as of December 31, 2022	$	560
Foreign currency translation adjustments	12
Other	(43)
Balance as of March 31, 2023	$	529

The following table outlines the activity related to contract liabilities:

$ in thousands
Balance as of December 31, 2022	$	10,348
Payments received in advance of performance	1,464
Revenue recognized	(774)
Recognition of consideration payable associated with Project Warrants	(76)
Other	4
Balance as of March 31, 2023	$	10,966