Program Summaries

Summaries of all the Renewable and Alternative Energy Portfolio Standard programs.

RPS Class I and II

The Massachusetts Renewable Energy Portfolio Standard (RPS) requires retail electricity suppliers (both regulated distribution utilities and competitive suppliers) obtain a percentage of the electricity they serve to their customers from qualifying renewable energy facilities. The RPS began with a compliance obligation of one percent in 2003, and increased by one-half percent annually until it reached four percent in 2009. In 2009, as a part of the Green Communities Act of 2008, the RPS Class I annual obligation was set to increase by 1% annually and a new RPS Class II was created for existing renewable energy facilities. Each Class has different annual compliance requirements as well as different eligibility criteria for qualifying facilities.

Suppliers meet their annual RPS obligations by acquiring a sufficient quantity of RPS-qualified renewable energy certificates (RECs) that are created, traded, and tracked at the New England Power Pool (NEPOOL) Generation Information System (GIS).

The NEPOOL GIS tracks all electricity generated within the ISO New England (ISO-NE) control area and fed onto the New England grid, as well as electricity exchanged between ISO-NE and adjacent control areas. For each megawatt hour (MWh) of electricity, whether renewable or not, one serial-numbered, electronic certificate is created and added to the NEPOOL GIS account of the Unit that generated the MWh. Certificates that represent renewable generation are coded accordingly and known as renewable energy certificates or RECs.

What are RECs?

Electricity produced by new renewable energy generators qualified for the RPS is generally broken into two products:

1) The electricity production that is consumed on-site or delivered to the grid

2) The positive environmental attributes associated with then energy production.

RECs represent the second product. One REC is created each time a qualified facility generates 1 megawatt hour (MWh) of electricity. In order for retail electricity suppliers to meet their annual compliance obligations established by the RPS, they must purchase a number of RECs equal to the percentage for that particular compliance year. For example, in 2020 all Suppliers will be required to purchase an amount of RECs equal to 15% of the total electricity they serve in Massachusetts.

Before a facility can generate RECs at NEPOOL GIS, the facility must first apply to DOER and receive a Statement of Qualification certifying its eligibility.

While REC values are generally determined by market supply and demand in a given compliance year, DOER plays a role in establishing a parameter on market prices by setting an Alternative Compliance Payment (ACP) Rate. This serves as a ceiling price and allows suppliers to meet their annual obligations by making payments at this rate in lieu of purchasing RECs. For every MWh a supplier is short of meeting its compliance obligation, it must make an ACP to DOER. The ACP Rate therefore incentivizes retail electricity suppliers to purchase RECs from qualified facilities at an amount lower than the ACP Rate in order to meet their compliance obligations. Revenue collected from ACPs is used by DOER to support new renewable energy, energy efficiency, and other clean energy projects throughout the Commonwealth.

RPS Class I

The RPS Class I requirement increases by one percent annually with no established end date. It is met through electricity production from qualified new renewable energy facilities. New renewable energy facilities are those that began commercial operation after 1997, generate electricity using any of the following technologies, and meet all other program eligibility criteria:

  • Solar photovoltaic
  • Solar thermal electric
  • Wind energy
  • Small hydropower
  • Landfill methane and anaerobic digester gas
  • Marine or hydrokinetic energy
  • Geothermal energy
  • Eligible biomass fuel

RPS Solar Carve-Out

On January 1, 2010, new regulations were filed that established a requirement for a portion of the RPS Class I renewable energy requirement to come from solar photovoltaic (PV) energy. This carve-out supported over 650 megawatts of new distributed solar PV energy facilities across the Commonwealth and stopped accepting new applications with the launch of the RPS Solar Carve-Out II Program in April 2014. Eligible facilities generate solar renewable energy certificates (SRECs) and will continue to do so until 2023, after which the facilities will generate Class I RECs.

RPS Solar Carve-Out II

The second phase of the Solar Carve-Out Program began with the promulgation of changes to the RPS Class I Regulation on April 25, 2014. The program was originally designed to continue supporting new solar photovoltaic (PV) installations until 1,600 MW of capacity was installed across the entire Commonwealth, but was extended in February 2016 and March 2017 as DOER was in the midst of developing a successor incentive program. The program supported 1,760 MW of new solar photovoltaic (PV) installations and stopped accepting new applications with the launch of the Solar Massachusetts Renewable Target (SMART) Program in November, 2018. Eligible facilities generated SREC IIs for a 40-quarter period from the time they were qualified, after which they generate Class I RECs.

RPS Class II Renewables

Similar to RPS Class I, this class pertains to generation units that use eligible renewable resources, but have an operation date prior to January 1,1998. Therefore, RPS Class II provides financial incentives for the continued operation of qualified pre-1998 renewable generation units. Eligible facilities generate Class II RECs and the annual percentage requirement varies from year to year per a formula in regulation.

RPS Class II Waste Energy

This class includes generation units that are classified as Waste Energy Generation Units and are located in Massachusetts. Typically these units burn solid waste at extremely high temperatures to generate electricity or steam power, in addition to providing funding to support recycling programs in Massachusetts. Eligible facilities generated Class II Waste Energy Certificates (WECs) and the annual percentage requirement is fixed at 3.7% per year for the years 2021 through 2025 after which it reverts to 3.5% per year.

Alternative Portfolio Standard (APS)

The Alternative Energy Portfolio Standard (APS) was established as of January 1, 2009, under the Green Communities Act of 2008. The APS offers a new opportunity for Massachusetts businesses, institutions, and governments to receive an incentive for installing eligible alternative energy systems, which are not necessarily renewable, but contribute to the Commonwealth's clean energy goals by increasing energy efficiency and reducing the need for conventional fossil fuel-based power generation. Similar to the RPS, it requires a certain percentage of the state's electric load to be met by eligible technologies, which for APS include Combined Heat and Power (CHP), flywheel storage, and efficient steam technologies. Eligible facilities generate Alternative Energy Certificates (AECs) and the annual percentage requirement increases by 0.25% per year indefinitely.

Clean Peak Energy Standard 

The Clean Peak Energy Standard is designed to provide incentives to clean energy technologies that can supply electricity or reduce demand during seasonal peak demand periods established by DOER.  The Clean Peak Energy Standard (CPS) was part of An Act to Advance Clean Energy, which was signed into law in August 2018.  Clean Peak Resources include new Class I Renewable Energy Resources, Existing Class I / Class II resources that are paired with an Energy Storage System, Energy Storage Systems, and Demand Response Resources.  Any qualified resource that generates, dispatches or discharges energy to the electric grid during a Seasonal Peak Period will generate Clean Peak Certificates.  Clean Peak Certificates can be sold to retail electricity suppliers, which are required to meet a baseline minimum percentage of sales each year.  DOER is charged with establishing four Seasonal Peak Periods in which resources must operate, determine a metering and verification protocol to ensure that all data is collected, reviewed and reported in a consistent manner, set the Alternative Compliance Payment rate and procurement process, and establish annual compliance requirements.  


Clean Energy Standard (CES)

Overseen by Massachusetts Department of Environmental Protection

In response to the Global Warming Solutions Act (GWSA) and the resultant Order 569 that stipulated greenhouse gas emissions reductions for the Commonwealth, the Department of Environmental Protection (DEP) promulgated the Clean Energy Standard (CES) through 310 CMR 7.75.

Beginning in 2018, the Clean Energy Standard (CES) sets a minimum percentage of electricity sales that utilities and competitive retail suppliers must procure from clean energy sources.  The minimum percentage begins at 16% in 2018, and increases 2% annually to 80% in 2050.  The CES is met through acquisition of Clean Energy Credits (CECs) or by making an Alternative Compliance Payment (75% of RPS ACP from 2018 to 2020, and 50% of the RPS ACP thereafter).

  • RPS Class I compliance (13% in 2018) counts toward compliance with the CES (16% in 2018).  Thus, the net incremental CES requirement for 2018 is 3%.
  • Any RPS Class I qualified generation attributes will also qualify for CECs.
  • Technologies that meet the emissions and vintage requirement will qualify for CECs, as well as energy procured under the 2016 Energy Diversity Act (e.g., 83d).
  • Existing customer contracts on or before August 11, 2017, will be exempt only for incremental CES obligation over and above the RPS obligation in any year.

For further information, click here.

Additional Resources

Contact   for Program Summaries


Alternative Energy Portfolio Standard (APS) Email Renewable Energy Division at
Renewable Energy Portfolio Standard (RPS) Email Renewable Energy Division at
Solar Carve-out (SREC) and Solar Carve-out II (SREC II) Email Renewable Energy Division at
Solar Massachusetts Renewable Target (SMART) Email Renewable Energy Division at


100 Cambridge St., 9th Floor, Boston, MA 02114

Help Us Improve  with your feedback

Please do not include personal or contact information.