Note 11. 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, 2016 (shares in thousands):

				Weighted		Weighted
				Average		Average
	Options			Exercise Price		Remaining
	Outstanding			Outstanding		Contractual Life
Outstanding at January 1, 2016		12,795		$	5.89		7.82
Granted		2,974			5.70
Exercised		(912	)		2.81
Cancelled / forfeited		(866	)		8.38
Outstanding at June 30, 2016		13,991		$	5.90		7.87

Options vested and exercisable at June 30, 2016		6,957		$	4.71		6.77

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, 2016 (shares in thousands):

				Weighted
				Average Grant
				Date Fair
	Shares			Value
Unvested balance at January 1, 2016		1,506		$	10.44
Granted		2,156			6.07
Issued		(149	)		9.38
Cancelled / forfeited		(128	)		6.74
Unvested balance at June 30, 2016		3,385		$	7.70

Employee Stock Purchase Plan

In July 2015, the board of directors approved the 2015 Employee Stock Purchase Plan (“ESPP”). Eligible employees are offered shares bi-annually through two six month offering periods, which begin on the first trading day on or after May 15 and November 15 of each year. The first offering period began on November 16, 2015. 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 and 2,000 shares per employee per offering period.

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,
	2016		2015		2016		2015
Cost of operating leases and incentives	$	632	$	248	$	839	$	297
Cost of solar energy systems and product sales		117		35		198		112
Sales and marketing		1,890		1,209		3,508		1,636
Research and development		149		64		246		126
General and administration		2,050		1,645		3,856		4,250
Total	$	4,838	$	3,201	$	8,647	$	6,421