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 September 30, 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 September 30, 2016 and December 31, 2015 are as follows:

	2016			2015
Total future minimum lease payments receivable	$	248,196,665		$	387,612,418
Less: executory cost		(70,089,703	)		(93,054,738	)
Less: unearned interest income		(61,430,134	)		(154,799,027	)
Investment in sales-type leases, net		116,676,828			139,758,653
Current portion		6,948,365			6,679,019
Noncurrent portion	$	109,728,463		$	133,079,634

As of September 30, 2016, the future minimum rentals to be received on non-cancelable sales-type leases by years are as follows:

2017	$	25,907,888
2018		19,977,407
2019		20,284,586
2020		21,647,694
2021		23,317,982
Thereafter		137,061,108
Total	$	248,196,665