Renewable Portfolio Standard

September 01, 2023


Massachusetts' 1997 electric-utility restructuring legislation created the framework for a renewable portfolio standard (RPS). In April 2002, the Massachusetts Department of Energy Resources (DOER) adopted RPS regulations. The RPS was significantly expanded by legislation enacted in July 2008 (Green Communities Act, S.B. 2768), which established two separate renewable standards -- a standard for “Class I” renewables, and a standard for “Class II” renewables -- as well as an Alternative Energy Portfolio Standard.

Class I Requirements (New Resources)

Under the Class I Renewable Portfolio Standard, all retail electricity suppliers must provide a minimum percentage of kilowatt-hour (kWh) sales to end-use customers in Massachusetts from eligible renewable energy resources installed after December 31, 1997, according to the following schedule:

  • 1.0% of sales by 12/31/2003
  • 1.5% of sales by 12/31/2004
  • 2.0% of sales by 12/31/2005
  • 2.5% of sales by 12/31/2006
  • 3.0% of sales by 12/31/2007
  • 3.5% of sales by 12/31/2008
  • 4.0% of sales by 12/31/2009
  • 5.0% of sales by 12/31/2010
  • 6.0% of sales by 12/31/2011
  • 7.0% of sales by 12/31/2012
  • 8.0% of sales by 12/31/2013
  • 9.0% of sales by 12/31/2014
  • 10.0% of sales by 12/31/2015
  • 11.0% of sales by 12/31/2016
  • 12.0% of sales by 12/31/2017
  • 13.0% of sales by 12/31/2018
  • 14.0% of sales by 12/31/2019
  • 16.0% of sales by 12/31/2020
  • 18.0% of sales by 12/31/2021
  • 20.0% of sales by 12/31/2022
  • 22.0% of sales by 12/31/2023
  • 24.0% of sales by 12/31/2024
  • 27.0% of sales by 12/31/2025
  • 30.0% of sales by 12/31/2026
  • 33.0% of sales by 12/31/2027
  • 36.0% of sales by 12/31/2028
  • 39.0% of sales by 12/31/2029
  • 40.0% of sales by 12/31/2030, and an additional 1% of sales each year thereafter, with no stated expiration date

Eligible Class I resources include solar photovoltaics (PV); solar thermal electric energy; wind energy; ocean thermal, wave, or tidal energy; fuel cells utilizing renewable fuels; landfill gas; energy generated by certain new hydroelectric facilities, or certain incremental new energy from increased capacity or efficiency improvements at existing hydroelectric facilities; low-emission advanced biomass power conversion technologies using fuels such as wood, by-products or waste from agricultural crops, food or vegetative material, energy crops, algae, biogas, or liquid biofuels; marine or hydrokinetic energy; and geothermal energy.

Solar Carve-Out and Solar Carve-Out II

Starting in 2010, retail suppliers were directed to provide a portion of the required renewable energy under the Class I Standard from qualified in-state, interconnected solar facilities. The original Solar Carve-Out requirement was 400 MW. Applications for facilities seeking qualification under the Solar Carve-Out stopped being accepted in April 2014 when the Solar Carve-Out II Program came into effect. The Solar Carve-Out II required 1,600 MW of solar by 2020. 

Qualifying solar facilities (officially known as “Solar Carve-Out II Renewable Generation Units” in the regulations) are set at 6 MW (direct current DC) or less and must have become operational after December 31, 2012. Solar Carve-Out facilities cannot also qualify as Solar Carve-Out II facilities. The Solar Carve-Out and Solar Carve-Out II Minimum Standards for the corresponding compliance year can be found here.

The Solar Minimum Standard is calculated by dividing the annual solar compliance obligation in megawatt-hours (MWh) by the total RPS load obligation from the previous two years. The solar compliance obligation in turn is based on the difference in the Solar Renewable Energy Certificates (SRECs) generated during the past two years (see the DOER regulations for calculations and additional guidance).

The SREC II program was succeeded by the Solar Massachusetts Renewable Target (SMART) program, which is not an SREC program or tied to the state's RPS; and has a participation capacity of 3,200 MW. The SMART program officially launched on November 26, 2018, marking the last day that solar generation units in Massachusetts were able to qualify for the SREC II Program.

Class II Requirements (Existing Resources)

The Class II RPS requires all retail electricity suppliers to provide annually a percentage of kWh sales to end-use customers in Massachusetts from Class II renewables, starting in 2009. Eligible Class II renewables include systems operating before January 1, 1998, that generate electricity using solar PV; solar thermal electric energy; wind energy; ocean thermal, wave or tidal energy; fuel cells utilizing renewable fuels; landfill gas; energy generated by certain existing hydroelectric facilities up to 7.5 megawatts (MW) in capacity; low-emission advanced biomass power conversion technologies using fuels such as wood, by-products or waste from agricultural crops, food or vegetative waste, energy crops, biogas, or liquid biofuels; marine or hydrokinetic energy; or geothermal energy. The Minimum Standards for 2023 and 2024/2025 are 3.4721% and 3.6%, respectively. The calculation is based on a formula established in regulation, and future Class II updates can be found here.

Class II Waste Energy Requirements

In addition, there is a separate Class II Waste Energy Minimum Standard that requires all retail electricity suppliers to provide an annual percentage of kWh sales to end-use customers in Massachusetts from waste energy (defined as the electrical energy created from the combustion of municipal solid waste) starting in 2009. The standard for compliance years 2021 through 2025 is equal to 3.7% of electrical energy sales and will equal 3.5% starting in 2026. Eligible waste energy generation units must have and maintain a state-approved recycling program, must comply with the Massachusetts Department of Environmental Protection’s air pollution and solid waste management regulations, and must allocate at least 50% of any revenue received from the sale of renewable energy certificates (RECs) generated to its recycling programs. Beginning in 2025 and every five years thereafter, the DOER shall conduct a review of the RPS Class II Waste Energy Minimum Standard. The DOER may modify the Minimum Standard for the following five years. 

Offshore Wind Target

The Legislature authorized the procurement of up to 5.6 GW of offshore wind energy by 2027. 


Retail electricity suppliers demonstrate compliance by submitting, in an annual compliance filing to the DOER, documentation that Class I RECs, Solar Carve-Out Renewable Energy Certificates (SRECs), Solar Carve-Out II Renewable Energy Certificates (SREC IIs), Class II RECs, and Class II Waste Energy Certificates have been secured. These certificates represent the environmental attributes of one megawatt-hour (MWh) of generation from an eligible facility under each class category. RECs generated in one year may be banked and used for compliance in either or both of the two subsequent years. In order to facilitate robust SREC I and SREC II markets that not only respond to market conditions but also provide price support, the DOER created the Solar Credit Clearinghouse, which exists under each program. 

Eligible facilities that generate solar renewable energy certificates (SRECs) can continue to do so until 2023, after which the facilities will generate Class I RECs. Eligible facilities that generate SREC IIs will do so for a 40-quarter period from the time they were qualified, after which they generate Class I RECs. System owners that wish to expand their original SREC system should consider applying to the RPS Class I program or the SMART program (eligibility varies). The respective renewable energy certificates (RECs) are issued by the New England Power Pool Generation Information System (NEPOOL-GIS) and are technically called GIS Certificates.

Alternative Compliance Payments

Retail suppliers may pay the alternative compliance payment (ACP) if they are unable to procure enough renewable energy attributes, however, the ACP rates are designed to be higher than the market price of RECs, SRECs, and SREC IIs. The DOER determined the initial ACP rate for each resource category. The ACP rates for Class I, Class II, and Class II Waste Energy increase (or decrease) annually based on the Consumer Price Index of the previous year. The Solar Carve-Out and Solar Carve-Out II ACP rates decrease annually per 10-year schedules. The base year ACP rates and current ACP rates can be found on the DOER's website. Massachusetts RPS compliance reports are available on the DOER website.

Program Overview

Implementing Sector: State
Category: Regulatory Policy
State: Massachusetts
Incentive Type: Renewables Portfolio Standard
Web Site:
Start Date:
Eligible Renewable/Other Technologies:
  • Geothermal Electric
  • Solar Thermal Electric
  • Solar Photovoltaics
  • Wind (All)
  • Biomass
  • Hydroelectric
  • Municipal Solid Waste
  • Landfill Gas
  • Tidal
  • Wave
  • Ocean Thermal
  • Wind (Small)
  • Hydroelectric (Small)
  • Anaerobic Digestion
  • Fuel Cells using Renewable Fuels
  • Offshore Wind
Standard: Class I (New Resources): 40% of by 2030 and an additional 1% each year thereafter
Class II (Renewables): 3.47% in 2023 and 3.6% in 2024 and 2025
Class II (Waste Energy): 3.7% from 2023-2025, 3.5% starting 2026
Technology Minimum: In-State Solar PV: Mandated target of 1600 MW by 2020
Offshore Wind: Mandated target of 5.6 GW by 2027
Compliance Multipliers: None
REC Lifetime: Three years
Credit Trading/Tracking System: Yes (NEPOOL-GIS)
Alternative Compliance Payment: Vary by year and tier


Name: M.G.L. ch. 25A, § 11F
Date Enacted: 11/25/1997
Effective Date: 4/2002
Expiration Date: Not specified
Name: 225 CMR 14.00
Date Enacted: 12/20/2010 (subsequently amended)
Effective Date: 01/07/2011
Name: 225 CMR 15.00
Effective Date: 06/12/2009


Name: Massachusetts Department of Energy Resources
Organization: DOER RPS Program
Address: 100 Cambridge St. 9th Floor
Boston MA 02114
Phone: (617) 626-7300

This information is sourced from DSIRE; the most comprehensive source of information on incentives and policies that support renewables and energy efficiency in the United States. Established in 1995, DSIRE is operated by the N.C. Clean Energy Technology Center at N.C. State University.