Revenue Recognition

6 Months Ended

Jun. 30, 2020

Revenue from Contract with Customer [Abstract]

Revenue Recognition

Revenue Recognition

Deferred Revenue and Customer Deposits

Deferred revenue and customer deposits as of June 30, 2020 and December 31, 2019 consisted of the following (in thousands):

	June 30, 2020		December 31, 2019
Deferred revenue	$	162,186	$	168,223
Deferred incentive revenue	7,067		7,397
Customer deposits	48,375		39,101
Deferred revenue and customer deposits	$	217,628	$	214,721

Deferred revenue activity during the three and six months ended June 30, 2020 and 2019 consisted of the following (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
			As Restated				As Restated
Beginning balance	$	170,034	$	140,734	$	168,223	$	140,130
Additions	159,142		189,138		297,254		307,497
Revenue recognized	(166,990)		(171,886)		(303,291)		(289,641)
Ending balance	$	162,186	$	157,986	$	162,186	$	157,986

Deferred revenue is equivalent to the total transaction price allocated to the performance obligations that are unsatisfied, or partially unsatisfied, as of the end of the period. The significant component of deferred revenue at the end of the period consists of performance obligations relating to the provision of maintenance services under current contracts and future renewal periods. These obligations provide customers with material rights over a period that we estimate will be largely commensurate with the period of their expected use of the associated Energy Server. As a result, we expect to recognize these amounts as revenue over a period of up to 21 years, predominantly on a cost-to-cost basis that reflects the cost of providing these services. Deferred revenue also includes performance obligations relating to product acceptance and installation. A significant amount of this deferred revenue is reflected as additions and revenue recognized in the same period and we expect to recognize all amounts within a year.

Revenue by source

We disaggregate revenue from contracts with customers into four revenue categories: (i) product, (ii) installation, (iii) services and (iv) electricity (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
			As Restated				As Restated
Revenue from contracts with customers:
Product revenue	$	116,197	$	144,081	$	215,756	$	235,007
Installation revenue	29,839		13,076		46,457		25,295
Services revenue	26,208		23,026		51,355		46,493
Electricity revenue	—		5,110		—		10,840
Total revenue from contract with customers	172,244		185,293		313,568		317,635
Revenue from contracts accounted for as leases:
Electricity revenue	15,612		15,033		30,987		29,692
Total revenue	$	187,856	$	200,326	$	344,555	$	347,327