4. INVESTMENT IN SALES-TYPE LEASES, NET

Under sales-type leases, Xi’an TCH leases the following systems: (i) TRT systems to Zhangzhi (13 year term) (termination of the lease was effective as of October 22, 2014 ); (ii) BMPG systems to Pucheng Phase I and II (15 and 11 year terms, respectively); (iii) BMPG systems to Shenqiu Phase I (11 year term); (iv) Shenqiu Phase II (9.5 year term); (v) WHPG system to Zhongbao (9 year term, this system was sold to Zhonggang on December 22, 2014); (vi) WHPG systems to Jitie (24 year term); (vii) WGPG systems to Yida (15 year term); and (viii) two BPRT systems to Shanxi Datong (30 year term). In addition, as of December 31, 2014, Erdos TCH leased power and steam generating systems from waste heat from metal refining to Erdos (five systems) for a term of twenty (20) years. The components of the net investment in sales-type leases as of December 31, 2014 and 2013 are as follows:

	2014		2013
Total future minimum lease payments receivable	$	583,820,886	$	560,187,391
Less: executory cost		(134,771,919)		(134,447,605)
Less: unearned interest income		(268,028,368)		(241,234,839)
Net investment in sales - type leases		181,020,599		184,504,947
Current portion		6,561,984		9,063,386
Noncurrent portion	$	174,458,615	$	175,441,561

As of December 31, 2014, the future minimum rentals to be received on non-cancelable sales-type leases by years are as follows:

2015	$	42,114,725
2016		40,398,758
2017		40,398,758
2018		40,300,703
2019		40,202,647
Thereafter		380,405,295
Total	$	583,820,886