Balance Sheet Components

12 Months Ended

Dec. 31, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Inventories

The components of inventory consist of the following (in thousands):


	December 31,
	2020		2019

Raw materials	$	79,090	$	67,829
Work-in-progress	29,063		21,207
Finished goods	33,906		20,570
	$	142,059	$	109,606

The inventory reserves were $14.0 million and $14.6 million as of December 31, 2020 and 2019, respectively.

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):


	December 31,
	2020		2019

Government incentives receivable	$	479	$	893
Prepaid hardware and software maintenance	5,227		3,763
Receivables from employees	5,160		6,130
Other prepaid expenses and other current assets	19,852		17,282
	$	30,718	$	28,068

Property, Plant and Equipment, Net

Property, plant and equipment, net, consists of the following (in thousands):


	December 31,
	2020		2019

Energy Servers	$	669,422	$	650,600
Computers, software and hardware	20,432		20,275
Machinery and equipment	106,644		101,650
Furniture and fixtures	8,455		8,339
Leasehold improvements	37,497		35,694
Building	46,730		40,512
Construction in progress	21,118		12,611
	910,298		869,681
Less: accumulated depreciation	(309,670)		(262,622)
	$	600,628	$	607,059

Depreciation expense related to property, plant and equipment, net, was $52.2 million, $78.6 million, and $53.1 million for the years ended December 31, 2020, 2019 and 2018, respectively. Depreciation expense incurred during the year ended December 31, 2019, included a decommissioning in PPA II, including the replacement during 2019 of 30 megawatts of installed Energy Servers with 27.5 megawatts of new systems sold, resulting in product cost of goods sold due to $52.5 million for the write-off of Energy Servers and $78.4 million for the cost of new systems sold, and electricity cost of revenue of

$22.6 million of accelerated depreciation charged. Additionally, during the year ended December 31, 2019, there was a decommissioning in PPA IIIb, including the replacement during 2019 of five megawatts of installed Energy Servers, resulting in product cost of goods sold of $18.0 million for the write-off of Energy Servers, and electricity cost of revenue of $1.7 million of accelerated depreciation charged in fourth quarter of 2019 related to the revised expected lives of installed systems, which we recognized in our consolidated statement of operations. There was no similar decommissioning activity or similar charges during the year ended December 31, 2020.

Property, plant and equipment, net, under operating leases by the PPA Entities was $368.0 million and $371.4 million as of December 31, 2020 and 2019, respectively. The accumulated depreciation for these assets was $115.9 million and $95.5 million as of December 31, 2020 and 2019, respectively. Depreciation expense related to our property, plant and equipment under operating leases by the PPA Entities was $23.8 million, $27.1 million and $25.5 million for the years ended December 31, 2020, 2019 and 2018, respectively.

Depreciation expense is included in cost of product, installation, service and electricity revenue as well as research and development, sales and marketing and general and administration expenses in our consolidated statements of operations.

Other Long-Term Assets

Other long-term assets consist of the following (in thousands):


	December 31,
	2020		2019

Prepaid and other long-term assets	$	24,116	$	29,153

Deferred commissions	6,732		5,007
Equity-method investments	1,954		5,733
Long-term deposits	1,709		1,759
	$	34,511	$	41,652

Accrued Warranty

Accrued warranty liabilities consist of the following (in thousands):


	December 31,
	2020		2019

Product warranty	$	1,549	$	2,345
Product performance	8,605		7,536
Maintenance services contracts	109		453
	$	10,263	$	10,334

Changes in the product warranty and product performance liabilities were as follows (in thousands):








Balances at December 31, 2018	$	9,668
Cumulative effect upon adoption of ASC 606	1,032
Accrued warranty, net	1,849
Warranty expenditures during period	(2,668)
Balances at December 31, 2019	9,881
Accrued warranty, net	5,944
Warranty expenditures during the year	(5,671)
Balances at December 31, 2020	$	10,154

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consist of the following (in thousands):


	December 31,
	2020		2019


Compensation and benefits	$	28,343	$	17,173
Current portion of derivative liabilities	19,116		4,834
Sales-related liabilities	14,479		416

Accrued installation	16,468		10,348
Sales tax liabilities	2,732		3,849
Interest payable	2,224		3,875
Other	28,642		29,789
	$	112,004	$	70,284

Other Long-Term Liabilities

Other long-term liabilities consist of the following (in thousands):


	December 31,
	2020		2019

Delaware grant	$	9,212	$	10,469

Other	3,067		17,544
	$	12,279	$	28,013

In March 2012, we entered into an agreement with the Delaware Economic Development Authority to provide a grant of $16.5 million to us as an incentive to establish a new manufacturing facility in Delaware and to provide employment for full- time workers at the facility over a certain period of time. We have received $12.0 million of the grant, which is contingent upon us meeting certain milestones related to the construction of the manufacturing facility and the employment of full-time workers at the facility through September 30, 2023. We repaid $1.5 million of the grant in 2017, and no additional amounts have been repaid since then. As of December 31, 2020, we have recorded $1.3 million in current liabilities and $9.2 million in other long-term liabilities for potential future repayments of this grant. See Note 14 - Commitments and Contingencies for a full description of the grant.