4. INVESTMENT IN SALES-TYPE LEASES, NET

Under sales-type leases, Xi’an TCH leases the following systems: (i) BMPG systems to Pucheng Phase I and II (15 and 11 year terms, respectively); (ii) BMPG systems to Shenqiu Phase I (11-year term); and (iii) Shenqiu Phase II (9.5-year term). In addition, as of December 31, 2016, Erdos TCH leased power and steam generating systems from waste heat from metal refining to Erdos (five systems) for a term of twenty years. The components of the net investment in sales-type leases as of December 31, 2016 and 2015 are as follows:

	2016 (Restated)			2015
Total future minimum lease payments receivable	$	96,886,262		$	387,612,418
Less: executory cost		(6,215,345	)		(93,054,738	)
Less: unearned interest income		(33,407,391	)		(154,799,027	)
Investment in sales-type leases, net		57,263,526			139,758,653
Current portion		8,103,583			6,679,019
Noncurrent portion	$	49,161,943		$	133,079,634

As of December 31, 2016, the future minimum rentals to be received on non-cancelable sales-type leases by years are as follows:

2017	$	20,469,944
2018		12,281,966
2019		12,281,966
2020		12,281,966
2021		12,281,966
Thereafter		27,288,454
Total	$	96,886,262