Stock-Based Compensation

6 Months Ended

Jun. 30, 2017

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

Stock-Based Compensation

Stock-Based Compensation

Stock Options

The following table summarizes the activity for all stock options under all of the Company’s equity incentive plans for the six months ended June 30, 2017 (shares and aggregate intrinsic value in thousands):

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic Value
Outstanding at January 1, 2017	12,897		$	5.94	7.49
Granted	4,585		5.03
Exercised	(207	)	2.49
Cancelled	(524	)	7.82
Outstanding at June 30, 2017	16,751		$	5.68	7.75	$	32,028
Options vested and exercisable at June 30, 2017	7,961		$	5.40	6.34	$	18,378

Restricted Stock Units

The following table summarizes the activity for all restricted stock units (“RSUs”) under all of the Company’s equity incentive plans for the six months ended June 30, 2017 (shares in thousands):

	Number of Awards		Weighted Average Grant Date Fair Value
Unvested balance at January 1, 2017	4,106		$	6.87
Granted	2,887		5.10
Issued	(538	)	6.15
Forfeited	(644	)	5.79
Unvested balance at June 30, 2017	5,811		$	6.13

Employee Stock Purchase Plan

In the quarter ended June 30, 2017, the Company modified the Company's 2015 Employee Stock Purchase Plan ("ESPP") by increasing the offering period to 24 months with four six month purchase periods and increasing the maximum number of shares an eligible employee can purchase during a purchase period to 10,000 shares. Each purchase period begins on the first trading day on or after May 15 and November 15 of each year. Employees may purchase a limited number of shares of the Company’s common stock via regular payroll deductions at a discount of 15% of the lower of the fair market value of the Company’s common stock on the first trading date of each offering period or on the exercise date. Employees may deduct up to 15% of payroll, with a cap of $25,000 of fair market value of shares in any calendar year.

Stock-Based Compensation Expense

The Company recognized stock-based compensation expense, including ESPP expenses, in the consolidated statements of operations as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Cost of operating leases and incentives	$	1,110	$	632	$	1,861	$	839
Cost of solar energy systems and product sales	156		117		270		198
Sales and marketing	807		1,890		2,724		3,508
Research and development	186		149		335		246
General and administration	3,256		2,050		6,199		3,856
Total	$	5,515	$	4,838	$	11,389	$	8,647