Solar Energy Systems, net

12 Months Ended

Dec. 31, 2018

Solar Energy Systems Disclosure [Abstract]

Solar Energy Systems, Net

Solar Energy Systems, net

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

	December 31,
	2018			2017
Solar energy system equipment costs	$	3,823,853		$	3,124,407
Inverters	396,054			317,390
Total solar energy systems	4,219,907			3,441,797
Less: accumulated depreciation and amortization	(535,891		)	(399,280		)
Add: construction-in-progress	136,001			119,053
Total solar energy systems, net	$	3,820,017		$	3,161,570

All solar energy systems, including construction-in-progress, have been leased to or are subject to signed Customer Agreements with customers. The Company recorded depreciation expense related to solar energy systems of $139.2 million, $112.8 million and $87.7 million for the years ended December 31, 2018, 2017 and 2016, respectively. The depreciation expense was reduced by the amortization of deferred grants of $7.8 million, $7.6 million and $13.0 million for the years ended December 31, 2018, 2017 and 2016, respectively.