6.	Solar Energy Systems, net

Solar energy systems, net consists of the following (in thousands):

	September 30, 2015			December 31, 2014
Solar energy system equipment costs	$	1,723,605		$	1,406,478
Inverters		162,203			123,910
Initial direct costs		58,246			36,279
Total solar energy systems		1,944,054			1,566,667
Less: accumulated depreciation and amortization		(193,776	)		(143,028	)
Add: construction-in-progress		86,769			56,584
Total solar energy systems, net	$	1,837,047		$	1,480,223

All solar energy systems, construction-in-progress, and inverters have been leased to or are subject to a signed Customer Agreement with customers. The Company recorded depreciation expense related to solar energy systems of $19.3 million and $51.3 million for the three and nine months ended September 30, 2015, respectively, and $14.2 million and $39.7 million for the three and nine months ended September 30, 2014, respectively. The depreciation expense was reduced by the amortization of deferred grants of $3.5 million and $10.6 million for the three and nine months ended September 30, 2015, respectively, and $3.5 million and $10.4 million for the three and nine months ended September 30, 2014, respectively.