(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. (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. (2) an additional one-half of 1 per cent of sales each year thereafter until December 31, 2009;
3. (3) an additional 1 per cent of sales each year thereafter until December 31, 2019;
4. (4) an additional 2 per cent of sales each year thereafter until December 31, 2024;
5. (5) an additional 3 per cent of sales each year thereafter until December 31, 2029; and (6) an additional 1 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, 2019 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.

(b) For the purposes of this subsection, a renewable energy generating source is one which generates electricity using any of the following:

1. (1) solar photovoltaic or solar thermal electric energy;
2. (2) wind energy;
3. (3) ocean thermal, wave or tidal energy;
4. (4) fuel cells utilizing renewable fuels;
5. (5) landfill gas;
6. (6) waste-to-energy which is a component of conventional municipal solid waste plant technology in commercial use;
7. (7) naturally flowing water and hydroelectric;
8. (8) low emission advanced power conversion technologies using fuels such as by-products or waste from agricultural crops, food or animals, energy crops, biogas, liquid biofuel including but not limited to biodiesel, organic refuse-derived fuel, or algae;
9. (9) geothermal energy; or (10) fusion energy; provided, however, that the calculation of a percentage of kilowatt-hours sales to end-use customers in the commonwealth from new renewable generating sources shall exclude clause (6). A renewable energy generating source may be located behind the customer meter within the ISO–NE, as defined in section 1 of chapter 164, control area if the output is verified by an independent verification system participating in the New England Power Pool Generation Information System, in this section called NEPOOL GIS, accounting system and approved by the department.

(c) New renewable energy generating sources meeting the requirements of this subsection shall be known as Class I renewable energy generating sources. For the purposes of this subsection, a Class I renewable energy generating source is one that began commercial operation after December 31, 1997, or represents the net increase from incremental new generating capacity after December 31, 1997 at an existing facility, where the facility generates electricity using any of the following:

1. (1) solar photovoltaic or solar thermal electric energy;
2. (2) wind energy;
3. (3) ocean thermal, wave or tidal energy;
4. (4) fuel cells utilizing renewable fuels;
5. (5) landfill gas;
6. (6) energy generated by new hydroelectric facilities, or incremental new energy from increased capacity or efficiency improvements at existing hydroelectric facilities; provided, however, that (i) each such new facility or increased capacity or efficiency at each such existing facility must meet appropriate and site-specific standards that address adequate and healthy river flows, water quality standards, fish passage and protection measures and mitigation and enhancement opportunities in the impacted watershed as determined by the department in consultation with relevant state and federal agencies having oversight and jurisdiction over hydropower facilities;

(d) Every retail electric supplier providing service under contracts executed or extended on or after January 1, 2009, shall provide a minimum percentage of kilowatt-hour sales to end-use customers in the commonwealth from Class II renewable energy generating sources. For the purposes of this section, a Class II renewable energy generating source is one that began commercial operation before December 31, 1997 and generates electricity using any of the following:

1. (1) solar photovoltaic or solar thermal electric energy;
2. (2) wind energy;
3. (3) ocean thermal, wave or tidal energy;
4. (4) fuel cells utilizing renewable fuels;
5. (5) landfill gas;
6. (6) energy generated by existing hydroelectric facilities, provided that such existing facility shall meet appropriate and site-specific standards that address adequate and healthy river flows, water quality standards, fish passage and protection measures and mitigation and enhancement opportunities in the impacted watershed as determined by the department in consultation with relevant state and federal agencies having oversight and jurisdiction over hydropower facilities; and provided further, that only energy from existing facilities up to 7.5 megawatts shall be considered renewable energy and no such facility shall involve pumped storage of water nor construction of any new dam or water diversion structure constructed later than January 1, 1998;
7. (7) waste-to-energy which is a component of conventional municipal solid waste plant technology in commercial use;
8. (8) low emission advanced power conversion technologies using fuels such as by-products or waste from agricultural crops, food or animals, energy crops, biogas, liquid biofuel including but not limited to biodiesel, organic refuse-derived fuel, or algae;
9. (9) marine or hydrokinetic energy as defined in section 3;
10. (10) geothermal energy; or (11) fusion energy. A facility in clause (7) shall not be a Class II renewable generating source unless it operates or contracts for one or more recycling programs approved by the department of environmental protection. At least 50 per cent of any revenue received by the facility through the sale of Massachusetts RPS–eligible renewable energy certificates shall be allocated to such recycling programs. A Class II renewable generating source may be located behind the customer meter within the ISO–NE control area provided that the output is verified by an independent verification system participating in the NEPOOL GIS accounting system and approved by the department.

11. (e) Every retail supplier shall annually provide to end-use customers in the commonwealth generation attributes from Class II energy facilities in an amount approved by the department; provided, however, that the department shall specify that a certain percentage of these requirements shall be met through energy generated from a specific technology or fuel type in subsection (d). Such minimum percentage requirement for kilowatt-hour sales from Class II energy generating sources may be adjusted by the department as necessary to promote the continued operation of existing energy generating resources that meet the requirements of said subsection (d), and may be met through kilowatt-hour sales to end-use customers from any energy generating source meeting the requirements of said subsection (d).

    [Subsection (f) applicable as provided by 2022, 179, Sec. 88.]