SECTION 1.Section 5 of Chapter 59 of the General Laws, as recently amended by Section 116 of Chapter 218 of the Acts of 2016, is hereby further amended in the first paragraph by striking at the end thereof “or Forty-fifth” and inserting in place thereof the following:- “Forty-fifth or Forty-fifth B”

SECTION 2.Said section is hereby further amended by inserting after paragraph Forty-fifth A the following new paragraph:-

“Forty-fifth B, Any qualified fuel cell powered system, the construction of which was commenced after January 1, 2017.  The exemption under this clause shall be allowed only for a period of twenty years from the date of completion of the construction of such facility; provided, however, that no exemption shall be allowed for any year within that period when such qualified fuel cell powered system is not capable of producing energy as required by this clause. A city or town, acting through the board or officer authorized by its legislative body, may execute an agreement for the payment in lieu of taxes with the owner of any qualified fuel cell powered system in the municipality such system is located. For the purposes of this clause, “any qualified fuel cell powered system” shall mean an integrated system comprised of a fuel cell stack assembly and associated components that utilizes and converts natural gas or renewable fuels into electricity used to produce and meet the annual energy needs of the real property upon which it is located.”