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


	September 30, 2023		December 31, 2022
Solar energy system equipment costs	$	12,068,415	$	10,529,852
Inverters and batteries	1,683,328		1,384,776
Total solar energy systems	13,751,743		11,914,628
Less: accumulated depreciation and amortization	(2,036,742)		(1,682,296)
Add: construction-in-progress	813,616		756,029
Total solar energy systems, net	$	12,528,617	$	10,988,361

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 $128.0 million and $108.3 million for the three months ended September 30, 2023 and 2022, respectively, and $365.4 million and $313.8 million for the nine months ended September 30, 2023 and 2022, respectively. The depreciation expense was reduced by the amortization of deferred grants of $2.0 million and $2.1 million for the three months ended September 30, 2023 and 2022, respectively, and $6.2 million and $6.2 million for the nine months ended September 30, 2023 and 2022, respectively.