View Filing Data

Print Document View Excel Document

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2013	Jul. 31, 2013
Document and Entity Information [Abstract]
Entity Registrant Name	Enphase Energy, Inc.
Entity Central Index Key	0001463101
Document Type	10-Q
Document Period End Date	Jun. 30, 2013
Amendment Flag	false
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		41,760,714

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 33,976	$ 45,294
Accounts receivable, net of allowances of $1,052 and $1,177, respectively	32,104	27,743
Inventory	17,906	19,843
Prepaid expenses and other	2,708	2,118
Total current assets	86,694	94,998
Property and equipment, net	25,141	25,541
Other assets	1,513	1,752
Total assets	113,348	122,291
Current liabilities:
Accounts payable	10,012	11,272
Accrued liabilities	19,348	19,266
Deferred revenues	1,258	933
Current portion of term loans	3,365	2,384
Total current liabilities	33,983	33,855
Long-term liabilities:
Deferred revenues	9,303	7,537
Warranty obligations	18,790	15,260
Other liabilities	394	307
Term loans	6,531	8,677
Total liabilities	69,001	65,636
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.00001 par value, 10,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.00001 par value, 100,000 shares authorized; 41,739 and 40,856 shares issued and outstanding as of June 30, 2013 and December 31, 2012, respectively	0	0
Additional paid-in capital	188,082	183,629
Accumulated deficit	(143,828)	(127,026)
Accumulated other comprehensive income	93	52
Total stockholders’ equity	44,347	56,655
Total liabilities and stockholders’ equity	$ 113,348	$ 122,291

Condensed Consolidated Balance Sheets (Unaudited ) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2013	Dec. 31, 2012
Allowances, accounts receivable	$ 1,052	$ 1,177
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	41,739,000	40,856,000
Common stock, shares outstanding	41,739,000	40,856,000
Preferred stock, par value (usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net revenues	$ 58,167	$ 55,697	$ 103,744	$ 98,297
Cost of revenues	41,883	42,096	75,259	75,389
Gross profit	16,284	13,601	28,485	22,908
Operating expenses:
Research and development	8,484	8,655	17,510	16,497
Sales and marketing	7,365	6,360	14,215	11,409
General and administrative	5,926	6,091	11,962	11,787
Total operating expenses	21,775	21,106	43,687	39,693
Loss from operations	(5,491)	(7,505)	(15,202)	(16,785)
Other income (expense), net:
Interest expense	(484)	(3,405)	(948)	(4,884)
Other income (expense)	(297)	(324)	(346)	316
Total other expense, net	(781)	(3,729)	(1,294)	(4,568)
Loss before income taxes	(6,272)	(11,234)	(16,496)	(21,353)
Provision for income taxes	(124)	(151)	(306)	(216)
Net loss attributable to common stockholders	$ (6,396)	$ (11,385)	$ (16,802)	$ (21,569)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	$ (0.15)	$ (0.29)	$ (0.41)	$ (1.05)
Shares used in computing net loss per share attributable to common stockholders, basic and diluted	41,617	39,461	41,384	20,584

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net loss attributable to common stockholders	$ (6,396)	$ (11,385)	$ (16,802)	$ (21,569)
Other comprehensive (loss) income:
Foreign currency translation adjustments	219	(11)	41	17
Comprehensive loss attributable to common stockholders	$ (6,177)	$ (11,396)	$ (16,761)	$ (21,552)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Net Income
-URI http://asc.fasb.org/extlink&oid=6518256

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.19)
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.18)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.22)
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Other Comprehensive Income
-URI http://asc.fasb.org/extlink&oid=6519514

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e565-108580

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 19
-Article 5

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 20
-Article 9

+ Details

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Cash flows from operating activities:
Net loss	$ (16,802)	$ (21,569)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,369	2,451
Provision for doubtful accounts	28	0
Net loss on disposal of assets	31	110
Non-cash interest expense	215	3,903
Stock-based compensation	2,910	1,708
Change in fair value of convertible preferred stock warrants	0	(520)
Changes in operating assets and liabilities:
Accounts receivable	(4,389)	7,810
Inventory	1,937	(19,738)
Prepaid expenses and other assets	(526)	(1,317)
Accounts payable, accrued and other liabilities	3,174	16,719
Deferred revenues	2,091	(21,402)
Net cash used in operating activities	(7,962)	(31,845)
Cash flows from investing activities:
Purchases of property and equipment	(3,467)	(8,013)
Net cash used in investing activities	(3,467)	(8,013)
Cash flows from financing activities:
Proceeds from term loans and debt	0	2,600
Repayments of term loans	(1,196)	(4,076)
Principal payments under capital leases	(40)	(63)
Proceeds from issuance of common stock under employee stock plans	1,534	44
Proceeds from issuance of common stock in IPO, net of underwriting discounts and commissions	0	58,609
Payment of offering costs	0	(1,828)
Net cash provided by financing activities	298	55,286
Effect of exchange rate changes on cash	(187)	17
Net (decrease) increase in cash and cash equivalents	(11,318)	15,445
Cash and cash equivalents—Beginning of period	45,294	51,524
Cash and cash equivalents—End of period	33,976	66,969
Supplemental disclosures of cash flow information:
Cash paid for interest	715	904
Noncash financing and investing activities:
Purchases of property and equipment included in accounts payable	305	1,692
Offering costs not yet paid	0	204
Conversion of convertible notes into common stock upon IPO	0	21,204
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon IPO	$ 0	$ 879

Overview and Summary of Significant Accounting Policies	6 Months Ended
Overview and Summary of Significant Accounting Policies	Jun. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Summary of Significant Accounting Policies	Overview and Summary of Significant Accounting Policies The Company Enphase Energy, Inc. ("Enphase" or the “Company”) designs, develops, and sells microinverter systems for the solar photovoltaic industry. The Company’s microinverter system consists of (i) an Enphase microinverter and related accessories that convert direct current (“DC”) power to grid-compliant alternating current (“AC”) power; (ii) an Envoy communications gateway device that collects and transmits performance information from each solar module to the Company’s hosted data center; and (iii) the Enlighten web-based software platform that collects and processes this information to enable customers to monitor and manage their solar power systems. The Company sells microinverter systems primarily to distributors who resell them to solar installers. The Company also sells directly to large installers as well as through original equipment manufacturers (“OEMs”) and strategic partners. On April 4, 2012, the Company completed its initial public offering ("IPO"), issuing 10,315,151 shares of common stock at an offering price of $6.00 per share. The net proceeds from the sale of the shares were $53.8 million, after deducting the underwriters’ discounts and commissions of $3.3 million and other offering costs of $4.8 million. Upon consummation of the IPO, the Company’s 22,220,856 outstanding shares of convertible preferred stock were automatically converted into 25,171,017 shares of common stock, and the $21.2 million outstanding balance of principal and accrued paid-in-kind interest in convertible notes were automatically converted into 3,533,988 shares of common stock at a conversion price equal to the IPO price of $6.00 per share Basis of Presentation, Consolidation and Related Party Transactions The accompanying condensed consolidated financial statements are presented in accordance with United States generally accepted accounting principles (“U.S. GAAP”). The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in the consolidation. Unaudited Interim Financial Information These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company's financial condition, results of operations, comprehensive loss and cash flows for the periods indicated. The results of operations for the three and six months ended June 30, 2013 are not necessarily indicative of the operating results for the full year. Certain information and footnote disclosures typically included in annual consolidated financial statements have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012. Significant Accounting Policies There have been no material changes in the Company's significant accounting policies, as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2012. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions about future events, and apply judgments that affect the reported amounts of assets, liabilities, revenue, expenses and the related disclosures. Significant estimates and assumptions reflected in the financial statements include revenue recognition, inventory valuation and accrued warranty obligations. Actual results could differ from those estimates.

Inventory

6 Months Ended

Jun. 30, 2013

Inventory Disclosure [Abstract]

INVENTORY

Inventory as of June 30, 2013 and December 31, 2012 consists of the following (in thousands):



	June 30, 2013		December 31, 2012
Raw materials	$	2,096	$	2,223
Finished goods	15,810		17,620
Total inventory	$	17,906	$	19,843

Warranty Obligations

6 Months Ended

Jun. 30, 2013

Product Warranties Disclosures [Abstract]

WARRANTY OBLIGATIONS

Changes in the Company’s warranty obligations during the six months ended June 30, 2013 and 2012 were as follows (in thousands):



	Six Months Ended June 30,
	2013			2012
Balance, at beginning of period	$	21,338		$	8,738
Warranty expense	8,124			3,698
Settlements	(2,685		)	(1,024		)
Balance, at end of period	26,777			11,412
Less current portion included in accrued liabilities	(7,987		)	(2,220		)
Long-term portion	$	18,790		$	9,192

For the three and six months ended June 30, 2013, warranty expense included $2.7 million and $4.7 million, respectively, resulting from changes in estimates, arising from increased failure rates related to certain previous generation products, lower warranty claim rates and higher estimated replacement costs for certain products.

For the three and six months ended June 30, 2012, warranty expense included $0.9 million and $1.2 million, respectively, resulting from changes in estimates related to higher estimated replacement costs for certain products.

Fair Value Measurements

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

FAIR VALUE OF FINANCIAL INSTRUMENTS

The accounting guidance defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance.

The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset’s or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value:


•	Level 1—Valuations based on quoted prices in active markets for identical assets or liabilities that the Company is able to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of such assets or liabilities do not entail a significant degree of judgment.


•	Level 2—Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly.


•	Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement.

Derivative Instruments—The Company utilizes foreign currency forward contracts to reduce the impact of foreign currency fluctuations arising from both sales and purchases denominated in Euros and the British Pound Sterling. As of June 30, 2013 and December 31, 2012, the aggregate gross notional amounts of outstanding foreign currency forward contracts, all with maturities of less than one year, were $16.7 million and $6.1 million, respectively.

The following table presents the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy at June 30, 2013 and December 31, 2012 (in thousands):



	Asset Derivatives				Liability Derivatives
	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Foreign currency forward contracts (Level 2)	$	20	$	—	$	140	$	268

For the six months ended June 30, 2013, the Company recognized a net gain of $56,000 related to foreign currency forward contracts.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Long-Term Debt

6 Months Ended

Jun. 30, 2013

Long-term Debt, by Current and Noncurrent [Abstract]

LONG-TERM DEBT

The Company’s long-term debt at June 30, 2013 and December 31, 2012 consists of the following (in thousands):



	June 30, 2013			December 31, 2012
Term loans	$	7,400		$	7,400
Equipment financing facility, net of unamortized discount of $63 and $94, respectively	2,496			3,661
Total debt	9,896			11,061
Less current portion	(3,365		)	(2,384		)
Long-term portion	$	6,531		$	8,677

As of June 30, 2013, the Company was a party to three debt agreements: (i) the $50.0 million revolving credit facility (the "Revolver") with Wells Fargo Bank, N.A., (ii) the facility with Hercules Technology Growth Capital, Inc. (“Hercules Facility”) consisting of a $7.4 million initial term loan and lending commitments of up to $15.6 million in additional term loans, and (iii) the $5.0 million equipment financing facility, also with Hercules. As of June 30, 2013, the Company has not drawn upon the Revolver or additional term loans available under the Hercules Facility. Each of these debt agreements is described in greater detail in the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Contingencies —The Company is not currently involved in any material legal proceedings. The Company may become involved in various legal proceedings and claims that arise in the ordinary course of business. Such matters are subject to uncertainty and there can be no assurance that such legal proceedings will not have a material adverse effect on its business, results of operations, financial position or cash flows.

Stock-Based Compensation

6 Months Ended

Jun. 30, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

STOCK-BASED COMPENSATION

The Company has adopted certain equity incentive and stock purchase plans as described in the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012.

Stock Options

The following is a summary of stock option activity for the six months ended June 30, 2013 (in thousands, except per share data):



	Number of Shares Outstanding		Weighted- Average Exercise Price per Share
Options outstanding—December 31, 2012	8,169		$	3.28
Granted	681		6.64
Exercised	(716	)	1.58
Canceled	(210	)	7.57
Options outstanding—June 30, 2013	7,924		3.61

Restricted Stock Units

The following is a summary of restricted stock unit activity for the six months ended June 30, 2013 (in thousands, except per share data):



	Restricted Stock Units		Weighted Average Fair Value per Share at Grant Date
Outstanding at December 31, 2012	248		$	5.53
Granted	155		6.40
Vested	(20	)	6.67
Canceled	(5	)	6.90
Outstanding at June 30, 2013	378		5.81

Stock-Based Compensation Expense

The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Cost of revenues	$	64	$	38	$	172	$	57
Research and development	438		384		916		657
Sales and marketing	397		268		775		464
General and administrative	576		312		1,047		530
Total	$	1,475	$	1,002	$	2,910	$	1,708

The following table summarizes stock-based compensation associated with each type of award for the periods presented (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Stock options and restricted stock units	$	1,432	$	1,002	$	2,717	$	1,708
Employee Stock Purchase Plan	43		—		193		—
Total	$	1,475	$	1,002	$	2,910	$	1,708

Valuation Assumptions

The fair value of options granted to employees for purposes of calculating stock-based compensation expense is estimated on the grant date using the Black-Scholes option-pricing model. This valuation model requires the Company to make assumptions and judgments about the inputs used in the calculation, including the expected term (weighted-average period of time that the options granted are expected to be outstanding), the volatility of the Company’s common stock, a risk-free interest rate, and expected dividend yield. The expected term for an option grant is calculated based on the simplified method. The expected volatility is based on an average of the historical volatilities of the common stock of several entities with characteristics similar to those of the Company. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. The Company’s expected dividend yield input was zero as it has not historically paid, nor does it expect in the future to pay, cash dividends on its common stock.

The fair value of each option granted during the periods presented was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:



	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
Expected term (in years)	4.3			6.0			4.4			6.0
Expected volatility	69.7		%	74.1		%	70.3		%	73.6		%
Annual risk-free rate of return	0.6		%	0.9		%	0.7		%	1.0		%
Dividend yield	0.0		%	0.0		%	0.0		%	0.0		%
Weighted average grant date fair value	$	3.74		$	4.87		$	3.59		$	5.16

As of June 30, 2013, there was approximately $12.9 million of total unrecognized compensation cost related to unvested equity awards expected to be recognized over a weighted-average period of 2.6 years.

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2013
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES No provision for U.S. federal or state income taxes has been made due to cumulative losses since the commencement of operations. The Company had a provision for income taxes of $124,000 and $151,000 for the three months ended June 30, 2013 and 2012, respectively, and $306,000 and $216,000 for the six months ended June 30, 2013 and 2012, respectively. The provision relates to the Company's subsidiaries located outside of the United States.

Net Loss Per Share Attributable to Common Stockholders

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS

In April 2012, all of the Company’s then outstanding convertible preferred stock automatically converted into common stock in connection with its IPO. For periods that ended prior to the conversion, basic and diluted net income per common share were presented in conformity with the two-class method required for participating securities.

Under the two-class method, net loss is allocated between common shares and other participating securities to the extent that the securities are required to share in the losses. The Company’s convertible preferred stock did not meet the definition of a participating security in periods of net losses as the convertible preferred stockholders did not have a contractual obligation to share in the Company’s losses. Accordingly, net losses were attributable to common stockholders. Subsequent to the IPO and the automatic conversion of the outstanding convertible preferred stock, the Company had no other participating securities and the two-class method is no longer applicable.

Basic net loss per share attributable to common stockholders is calculated by dividing net loss attributable to common stockholders by the weighted average number of shares outstanding for the period. The disproportional change in loss per share for the six months ended June 30, 2013, as compared to the same period in the prior year, is attributed to the effect of the IPO of 10.3 million shares of its common stock. In addition, the IPO also effected the automatic conversion of the Company's convertible preferred stock and convertible notes into 28.7 million shares of its common stock.

Diluted net loss per share attributable to common stockholders is calculated by dividing net loss attributable to common stockholders by the weighted average number of common shares and potential dilutive common share equivalents outstanding during the period if the effect is dilutive. The Company’s potentially dilutive common shares include convertible notes and convertible preferred stock prior to their conversion, outstanding stock options and warrants, shares issuable pursuant to the ESPP and non-vested restricted stock units.

The following table presents the potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders for the three and six months ended June 30, 2013 and 2012, respectively, because including them would have been anti-dilutive (in thousands):



	Three Months Ended June 30,		Six Months Ended June 30,
	2013	2012	2013	2012
Stock options to purchase common stock	7,878	7,191	7,893	8,126
Restricted stock units	358	42	303	125
Warrants to purchase common stock	312	331	322	331
Total	8,548	7,564	8,518	8,582

Related Party Transactions	6 Months Ended
Related Party Transactions	Jun. 30, 2013
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS KPCB Holdings, Inc. ("KPCB"), as nominee for certain funds of Kleiner Perkins Caufield & Byers, owned approximately 12 percent of the Company's outstanding shares as of June 30, 2013. For the three and six months ended June 30, 2013, the Company recognized revenues of $2.1 million from sales of microinverters to entities that are majority-owned by KPCB. For the three and six months ended June 30, 2012, the Company recognized revenues of $14.2 million and $16.8 million, respectively, from such entities.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References + Details

Overview and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation, Consolidation and Related Party Transactions	Basis of Presentation, Consolidation and Related Party Transactions The accompanying condensed consolidated financial statements are presented in accordance with United States generally accepted accounting principles (“U.S. GAAP”). The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in the consolidation.
Unaudited Interim Financial Information	Unaudited Interim Financial Information These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated interim financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company's financial condition, results of operations, comprehensive loss and cash flows for the periods indicated. The results of operations for the three and six months ended June 30, 2013 are not necessarily indicative of the operating results for the full year. Certain information and footnote disclosures typically included in annual consolidated financial statements have been condensed or omitted. Accordingly, these unaudited interim condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes in the Company's significant accounting policies, as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2012.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions about future events, and apply judgments that affect the reported amounts of assets, liabilities, revenue, expenses and the related disclosures. Significant estimates and assumptions reflected in the financial statements include revenue recognition, inventory valuation and accrued warranty obligations. Actual results could differ from those estimates.

Inventory (Tables)

6 Months Ended

Jun. 30, 2013

Inventory Disclosure [Abstract]

Schedule of inventory

Inventory as of June 30, 2013 and December 31, 2012 consists of the following (in thousands):



	June 30, 2013		December 31, 2012
Raw materials	$	2,096	$	2,223
Finished goods	15,810		17,620
Total inventory	$	17,906	$	19,843

Warranty Obligations (Tables)

6 Months Ended

Jun. 30, 2013

Product Warranties Disclosures [Abstract]

Changes in the Company's product warranty liability

Changes in the Company’s warranty obligations during the six months ended June 30, 2013 and 2012 were as follows (in thousands):



	Six Months Ended June 30,
	2013			2012
Balance, at beginning of period	$	21,338		$	8,738
Warranty expense	8,124			3,698
Settlements	(2,685		)	(1,024		)
Balance, at end of period	26,777			11,412
Less current portion included in accrued liabilities	(7,987		)	(2,220		)
Long-term portion	$	18,790		$	9,192

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosures [Abstract]

Schedule of financial instruments that are measured at fair value on a recurring basis



	Asset Derivatives				Liability Derivatives
	June 30, 2013		December 31, 2012		June 30, 2013		December 31, 2012
Foreign currency forward contracts (Level 2)	$	20	$	—	$	140	$	268

Long-Term Debt (Tables)

6 Months Ended

Jun. 30, 2013

Long-term Debt, by Current and Noncurrent [Abstract]

Schedule of long-term debt

The Company’s long-term debt at June 30, 2013 and December 31, 2012 consists of the following (in thousands):



	June 30, 2013			December 31, 2012
Term loans	$	7,400		$	7,400
Equipment financing facility, net of unamortized discount of $63 and $94, respectively	2,496			3,661
Total debt	9,896			11,061
Less current portion	(3,365		)	(2,384		)
Long-term portion	$	6,531		$	8,677

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

+ Details

Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of summary of stock option activity

The following is a summary of stock option activity for the six months ended June 30, 2013 (in thousands, except per share data):



	Number of Shares Outstanding		Weighted- Average Exercise Price per Share
Options outstanding—December 31, 2012	8,169		$	3.28
Granted	681		6.64
Exercised	(716	)	1.58
Canceled	(210	)	7.57
Options outstanding—June 30, 2013	7,924		3.61

Schedule of restricted stock unit activity

The following is a summary of restricted stock unit activity for the six months ended June 30, 2013 (in thousands, except per share data):



	Restricted Stock Units		Weighted Average Fair Value per Share at Grant Date
Outstanding at December 31, 2012	248		$	5.53
Granted	155		6.40
Vested	(20	)	6.67
Canceled	(5	)	6.90
Outstanding at June 30, 2013	378		5.81

Schedule of components of stock-based compensation expense in the consolidated statement of operations, by report line

The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Cost of revenues	$	64	$	38	$	172	$	57
Research and development	438		384		916		657
Sales and marketing	397		268		775		464
General and administrative	576		312		1,047		530
Total	$	1,475	$	1,002	$	2,910	$	1,708

Schedule of stock-based compensation expense by award type

The following table summarizes stock-based compensation associated with each type of award for the periods presented (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2013		2012		2013		2012
Stock options and restricted stock units	$	1,432	$	1,002	$	2,717	$	1,708
Employee Stock Purchase Plan	43		—		193		—
Total	$	1,475	$	1,002	$	2,910	$	1,708

Schedule of valuation assumptions of stock options

The fair value of each option granted during the periods presented was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:



	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
Expected term (in years)	4.3			6.0			4.4			6.0
Expected volatility	69.7		%	74.1		%	70.3		%	73.6		%
Annual risk-free rate of return	0.6		%	0.9		%	0.7		%	1.0		%
Dividend yield	0.0		%	0.0		%	0.0		%	0.0		%
Weighted average grant date fair value	$	3.74		$	4.87		$	3.59		$	5.16

Net Loss Per Share Attributable to Common Stockholders (Tables)

6 Months Ended

Jun. 30, 2013

Earnings Per Share [Abstract]

Schedule of potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders



	Three Months Ended June 30,		Six Months Ended June 30,
	2013	2012	2013	2012
Stock options to purchase common stock	7,878	7,191	7,893	8,126
Restricted stock units	358	42	303	125
Warrants to purchase common stock	312	331	322	331
Total	8,548	7,564	8,518	8,582

Overview and Summary of Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended
	Apr. 04, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Common stock, shares issued	10,315,151
Stock issued during period offering price	$ 6.00
Proceeds from issuance of common stock in IPO, net of underwriting discounts and commissions	$ 53,800	$ 0	$ 58,609
Underwriters Discounts and Commissions	3,300
Other estimated offering costs	$ 4,800
Convertible preferred stock, shares outstanding	22,220,856	0		0
Conversion of convertible preferred stock into common stock	25,171,017
Convertible notes, outstanding balance of principal and accrued paid in kind interest	$ 21,200
Conversion of notes into common stock	3,533,988
Conversion price of convertible notes	$ 6.00

Inventory (Details) - USD ($) $ in Thousands	Jun. 30, 2013	Dec. 31, 2012
Schedule of inventory
Raw materials	$ 2,096	$ 2,223
Finished goods	15,810	17,620
Total inventory	$ 17,906	$ 19,843

Warranty Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Warranty Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Changes in the Company's product warranty liability
Balance, at beginning of period			$ 21,338	$ 8,738
Warranty expense			8,124	3,698
Settlements			(2,685)	(1,024)
Balance, at end of period	$ 26,777	$ 11,412	26,777	11,412
Less current portion included in accrued liabilities	(7,987)	(2,220)	(7,987)	(2,220)
Long-term portion	18,790	9,192	18,790	9,192	$ 15,260
Increase in warranty expense due to changes in estimates	$ 2,700	$ 900	$ 4,700	$ 1,200

Fair Value Measurements (Details) - Fair value, measurements, recurring [Member] - Level 2 [Member] - USD ($) $ in Thousands	Jun. 30, 2013	Dec. 31, 2012
Asset Derivatives
Foreign currency forward contracts (Level 2)	$ 20	$ 0
Liability Derivatives
Foreign currency forward contracts (Level 2)	$ 140	$ 268

Fair Value Measurements (Details Textual) - Not designated as hedging instrument [Member] - Foreign exchange forward [Member] - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Derivative [Line Items]
Notional amount of foreign currency	$ 16,700	$ 6,100
Net gain on foreign currency	$ 56

Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2013	Dec. 31, 2012
Schedule of long-term debt
Total debt	$ 9,896	$ 11,061
Less current portion	(3,365)	(2,384)
Long-term portion	6,531	8,677
Term loans [Member]
Schedule of long-term debt
Total debt	7,400	7,400
Equipment Financing Facility [Member]
Schedule of long-term debt
Total debt	2,496	3,661
Unamortized discount	$ 63	$ 94

Long-Term Debt (Details Textual)	6 Months Ended
Long-Term Debt (Details Textual)	Jun. 30, 2013 USD ($) debt_agreement
Debt Instrument [Line Items]
Number of debt agreements \| debt_agreement	3
Wells Fargo Bank [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit line facility	$ 50,000,000.0
Hercules Technology Growth Capital Inc [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Credit line facility	7,400,000.0
Debt instrument additional borrowing amount	15,600,000.0
Hercules Technology Growth Capital Inc [Member] \| Equipment Financing Facility [Member]
Debt Instrument [Line Items]
Credit line facility	$ 5,000,000.0

Stock-Based Compensation Stock Option Activity (Details) shares in Thousands	6 Months Ended
	Jun. 30, 2013 $ / shares shares
Number of Shares Outstanding
Options outstanding—December 31, 2012 \| shares	8,169
Granted (in shares) \| shares	681
Exercised (in shares) \| shares	(716)
Canceled (in shares) \| shares	(210)
Options outstanding—June 30, 2013 (in shares) \| shares	7,924
Weighted- Average Exercise Price per Share
Options outstanding—December 31, 2012 (in usd per share) \| $ / shares	$ 3.28
Granted (in usd per share) \| $ / shares	6.64
Exercised (in usd per share) \| $ / shares	1.58
Canceled (in usd per share) \| $ / shares	7.57
Options outstanding—June 30, 2013 (in usd per share) \| $ / shares	$ 3.61

Stock-Based Compensation Restricted Stock Unit Activity (Details) - Restricted stock units [Member] shares in Thousands	6 Months Ended
	Jun. 30, 2013 $ / shares shares
Restricted Stock Units
Outstanding at December 31, 2012 (in shares) \| shares	248
Granted (in shares) \| shares	155
Vested (in shares) \| shares	(20)
Canceled (in shares) \| shares	(5)
Outstanding at June 30, 2013 (in shares) \| shares	378
Weighted Average Fair Value per Share at Grant Date
Outstanding at December 31, 2012 (in usd per share) \| $ / shares	$ 5.53
Granted (in usd per share) \| $ / shares	6.40
Vested (in usd per share) \| $ / shares	6.67
Canceled (in usd per share) \| $ / shares	6.90
Outstanding at June 30, 2013 (in usd per share) \| $ / shares	$ 5.81

Stock-Based Compensation Components of Stock-based Compensation Expense by Report Line (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	$ 1,475	$ 1,002	$ 2,910	$ 1,708
Cost of revenues [Member]
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	64	38	172	57
Research and development [Member]
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	438	384	916	657
Sales and marketing [Member]
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	397	268	775	464
General and administrative [Member]
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	$ 576	$ 312	$ 1,047	$ 530

Stock-Based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,475	$ 1,002	$ 2,910	$ 1,708
Employee stock options and restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,432	1,002	2,717	1,708
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 43	$ 0	$ 193	$ 0

Stock-Based Compensation Valuation Assumptions of Stock Options Under Black-Scholes Model (Details) - Stock options [Member] - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
The fair value of each option granted during the periods
Expected term	4 years 3 months 18 days	6 years	4 years 4 months 24 days	6 years
Expected volatility	69.70%	74.10%	70.30%	73.60%
Annual risk-free rate of return	0.60%	0.90%	0.70%	1.00%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted average grant date fair value	$ 3.74	$ 4.87	$ 3.59	$ 5.16

Stock-Based Compensation (Details Textual) $ in Millions	6 Months Ended
Stock-Based Compensation (Details Textual) $ in Millions	Jun. 30, 2013 USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total unrecognized compensation cost	$ 12.9
Weighted-average recognition period for unrecognized compensation cost	2 years 7 months 6 days

Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($)	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Tax Disclosure [Abstract]
Provision for U.S. federal or state income taxes			$ 0
Provision for income taxes related to subsidiaries located outside the U.S.	$ 124,000	$ 151,000	$ 306,000	$ 216,000

Net Loss Per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	8,548	7,564	8,518	8,582
Stock options to purchase common stock [Member]
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	7,878	7,191	7,893	8,126
Restricted stock units [Member]
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	358	42	303	125
Warrants to purchase common stock [Member]
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	312	331	322	331

Net Loss Per Share Attributable to Common Stockholders (Details Textual)	Apr. 04, 2012 shares
Stock Issuance from Initial Public Offering [Abstract]
Common stock shares issued from the IPO	10,315,151
Conversion of preferred stock into common stock (in shares)	28,700,000

Related Party Transactions (Details) - KPCB Holdings, Inc. [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Related Party Transaction [Line Items]
Percentage of Company owned by related party	12.00%		12.00%
Revenue from related parties	$ 2.1	$ 14.2	$ 2.1	$ 16.8