S.C. Code § 12-65-30
2016 Act No. 179, Section 2, provides as follows:
"SECTION 2. This act takes effect upon approval by the Governor and first applies to credits claimed for income tax year 2016, regardless of when the credit was earned."
2016 Act No. 272, Section 2.B, provides as follows:
"B. This SECTION shall apply to all projects placed in service after December 31, 2014 and for all tax years for which final returns have not been filed as of April 30, 2016."