16. STOCK-BASED COMPENSATION

The following table summarizes the consolidated stock-based compensation expense by line item in the Consolidated Statements of Operations:



	Fiscal Year
(In thousands)	2017		2016		2015
Cost of Residential revenue	$	1,875	$	5,464	$	4,764
Cost of Commercial revenue	2,102		4,235		2,676
Cost of Power Plant revenue	3,917		10,878		5,904
Research and development	5,357		11,075		9,938
Sales, general and administrative	21,423		29,847		35,678
Total stock-based compensation expense	$	34,674	$	61,499	$	58,960

The following table summarizes the consolidated stock-based compensation expense by type of award:



	Fiscal Year
(In thousands)	2017		2016		2015
Restricted stock units	$	34,548	$	58,562	$	61,818
Change in stock-based compensation capitalized in inventory	126		2,937		(2,858		)
Total stock-based compensation expense	$	34,674	$	61,499	$	58,960

As of December 31, 2017, the total unrecognized stock-based compensation related to outstanding restricted stock units was $57.4 million, which the Company expects to recognize over a weighted-average period of 2.80 years.

Equity Incentive Programs

Stock-based Incentive Plans

The Company has three stock incentive plans currently: (i) the Third Amended and Restated 2005 SunPower Corporation Stock Incentive Plan ("2005 Plan"); (ii) the PowerLight Corporation Common Stock Option and Common Stock Purchase Plan ("PowerLight Plan"); and (iii) the SunPower Corporation 2015 Omnibus Incentive Plan ("2015 Plan"). The PowerLight Plan, which was adopted by PowerLight’s Board of Directors in October 2000, was assumed by the Company by way of the acquisition of PowerLight in fiscal 2007. Under the terms of all plans, the Company may issue incentive or non-statutory stock options or stock purchase rights to directors, employees and consultants to purchase common stock. The 2005 Plan was adopted by the Company’s Board of Directors in August 2005, and was approved by shareholders in November 2005. The 2015 Plan, which subsequently replaced the 2005 Plan, was adopted by the Company’s Board of Directors in February 2015, and was approved by shareholders in June 2015. The 2015 Plan allows for the grant of options, as well as grant of stock appreciation rights, restricted stock grants, restricted stock units and other equity rights. The 2015 Plan also allows for tax withholding obligations related to stock option exercises or restricted stock awards to be satisfied through the retention of shares otherwise released upon vesting.

The 2015 Plan includes an automatic annual increase mechanism equal to the lower of three percent of the outstanding shares of all classes of the Company’s common stock measured on the last day of the immediately preceding fiscal year, 6.0 million shares, or such other number of shares as determined by the Company’s Board of Directors. In fiscal 2015, the Company’s Board of Directors voted to reduce the stock incentive plan’s automatic increase from 3% to 2% for 2016. Subsequent to the adoption of the 2015 Plan, no new awards are being granted under the 2005 Plan, or the PowerLight Plan. Outstanding awards granted under these plans continue to be governed by their respective terms. As of December 31, 2017, approximately 8.8 million shares were available for grant under the 2015 Plan.

Incentive stock options, nonstatutory stock options, and stock appreciation rights may be granted at no less than the fair value of the common stock on the date of grant. The options and rights become exercisable when and as determined by the Company’s Board of Directors, although these terms generally do not exceed ten years for stock options. Under the 2005 Plans, the options typically vest over five years with a one-year cliff and monthly vesting thereafter. Under the PowerLight Plan, the options typically vest over five years with yearly cliff vesting. The Company has not granted stock options since fiscal 2008, and accordingly all outstanding options are fully vested. Under the 2005 and 2015 plans, the restricted stock grants and restricted stock units typically vest in equal installments annually over three or four years.

The majority of shares issued are net of the minimum statutory withholding requirements that the Company pays on behalf of its employees. During fiscal 2017, 2016, and 2015, the Company withheld 0.6 million, 1.0 million and 1.4 million shares, respectively, to satisfy the employees' tax obligations. The Company pays such withholding requirements in cash to the appropriate taxing authorities. Shares withheld are treated as common stock repurchases for accounting and disclosure purposes and reduce the number of shares outstanding upon vesting.

Restricted Stock and Stock Options

The following table summarizes the Company’s non-vested restricted stock activities:



	Restricted Stock Units
	Shares (in thousands)		Weighted-Average Grant Date Fair Value Per Share¹
Outstanding as of December 28, 2014	6,555		18.88
Granted	2,695		29.77
Vested²	(3,560	)	15.31
Forfeited	(627	)	22.99
Outstanding as of January 3, 2016	5,063		26.68
Granted	4,978		18.81
Vested²	(2,837	)	23.47
Forfeited	(1,057	)	26.30
Outstanding as of January 1, 2017	6,147		21.85
Granted	4,863		6.76
Vested²	(1,738	)	25.87
Forfeited	(1,979	)	18.15
Outstanding as of December 31, 2017	7,293		11.83


¹	The Company estimates the fair value of its restricted stock awards and units at its stock price on the grant date.


²	Restricted stock awards and units vested include shares withheld on behalf of employees to satisfy the minimum statutory tax withholding requirements.

There were no options outstanding and exercisable as of December 31, 2017 and 322 options exercised in fiscal 2017. The intrinsic value of options exercised in fiscal 2017, 2016, and 2015 were $1.7 thousand, zero, and $1.0 million, respectively. There were no stock options granted in fiscal 2017, 2016, and 2015.