SECTION 1. Section 11F of Chapter 25A, as appearing in the 2018 Official Edition, is hereby amended by striking out the subsection (a) and inserting in place thereof the following:-

(a) The department shall establish a renewable energy portfolio standard for all retail electricity suppliers selling electricity to end-use customers in the commonwealth. By December 31, 1999, the department shall determine the actual percentage of kilowatt-hours sales to end-use customers in the commonwealth which is derived from existing renewable energy generating sources. Every retail supplier shall provide a minimum percentage of kilowatt-hours sales to end-use customers in the commonwealth from Class I renewable energy generating sources, according to the following schedule: (1) an additional 1 per cent of sales by December 31, 2003, or 1 calendar year from the final day of the first month in which the average cost of any renewable technology is found to be within 10 per cent of the overall average spot-market price per kilowatt-hour for electricity in the commonwealth, whichever is sooner; (2) an additional one-half of 1 per cent of sales each year thereafter until December 31, 2009; (3) an additional 1 per cent of sales each year thereafter until December 31, 2021; and (4) an additional 3 per cent of sales every year thereafter. Any electric load served under a retail electricity supply contract executed or extended not later than December 31, 2018, shall be exempt from any incremental compliance obligation under this section that occurs as a result of an increase or a new requirement imposed on or after January 1, 2021 on the minimum percentage of kilowatt-hour sales to end-use customers that must be derived from Class I RPS eligible resources. For the purpose of this subsection, a new renewable energy generating source is one that begins commercial operation after December 31, 1997, or that represents an increase in generating capacity after December 31, 1997, at an existing facility. Commencing on January 1, 2009, such minimum percentage requirement shall be known as the ''Class I'' renewable energy generating source requirement.