What is an MREC?
"MREC" is the common name for a Massachusetts renewable energy certificate. The official name is a Massachusetts RPS Class I Renewable Energy Certificate, or Class I REC. Every time a solar system produces 1,000 kilowatt-hours (one megawatt-hour) of electricity, it can earn one certificate, and the owner can sell it.
MRECs are real and they still pay. They are less common than they used to be, because most homeowners now enroll in the state's SMART 3.0 program instead, and you can't do both. This page explains how MRECs work, what they are worth today, and when they make more sense than SMART.
How renewable energy credits work
Massachusetts requires electricity suppliers to get a growing share of their power from renewable sources. This rule is called the Renewable Portfolio Standard (RPS). Suppliers prove they met it by buying Class I certificates, which are tracked in a regional registry called NEPOOL GIS.
That creates a market. A solar owner whose system is qualified as a Class I generator earns certificates as the system produces power, and suppliers buy them. Homeowners almost always sell through an aggregator, a company that registers the system, collects the certificates each quarter and sells them in bulk. Aggregators include Sol Systems and Xpansiv (formerly SRECTrade).
Before SMART existed, Massachusetts ran two solar-only certificate programs, SREC I and SREC II. Both are closed to new systems. Systems still earning SRECs move over to Class I certificates when their SREC term ends.
MRECs vs. SMART 3.0: why you can't have both
SMART 3.0 pays home solar owners a fixed rate for every kilowatt-hour their system produces. In exchange, your utility takes ownership of the system's renewable energy certificates for as long as you are enrolled. National Grid's SMART 3.0 tariff spells this out, and MassCEC's SMART 3.0 guide says the same: the certificates are assigned to your utility for the term of your participation.
So a home system can either enroll in SMART or sell MRECs, not both. Either way, you still get net metering credits on your electric bill for the extra power you send to the grid.
What MRECs are worth in 2026
MREC prices are set by the market, not by the state. In fall 2026, aggregator contract offers ran about $29 to $38 per certificate, depending on whether you lock a price for a couple of years or sell at the going rate. Prices have a practical ceiling near $40, because suppliers that come up short can pay the state's alternative compliance payment of $40 per megawatt-hour for 2026 instead of buying certificates.
For a home system that produces 10,000 kWh a year, that works out to 10 certificates, or roughly $290 to $380 a year before aggregator fees. A few things to know:
- Certificates are issued and paid quarterly, a few months after the power is produced, not monthly.
- Fixed-price contracts usually last only two to three years. After that, you get whatever the market pays.
- No price or term is guaranteed by the state, so treat any long-term projection as an estimate.
Who sells MRECs today?
MRECs are the better fit, or the only option, for a few groups of Massachusetts solar owners:
- Systems outside SMART. If a system didn't enroll in SMART or wasn't accepted, it can still qualify to sell certificates.
- Older SREC systems. Systems coming off SREC I or SREC II move to Class I certificates when their SREC term ends.
How to sell MRECs
- Pick an aggregator. Most homeowners sign with one. Aggregators typically handle the paperwork and offer a fixed-price contract or a market-rate option.
- Qualify the system with the state. The Department of Energy Resources (DOER) qualifies each system as a Class I generator. Your aggregator usually files this for you.
- Report production. An independent verifier reports your system's output to NEPOOL GIS each quarter, and certificates are issued from those readings.
- Get paid quarterly. The aggregator sells the certificates and pays you, minus its fee or spread.
Aggregators have quarterly application deadlines, so a missed deadline pushes your start to the next quarter.
Which is better for most homeowners?
For most Eversource, National Grid and Unitil customers, SMART 3.0 is the simpler and steadier choice. Systems enrolled in 2026 earn a fixed $0.03 per kWh for up to 20 years, or $0.06 per kWh for income-eligible households, paid by the utility on top of net metering. That $0.03 equals $30 per certificate, about the same as today's MREC contract offers, but locked in for far longer and without market risk.
MRECs make sense when your system isn't enrolled in SMART. If you are deciding between the two, ask your installer to show both on the same system. Our guide to paying for solar in 2026 explains how SMART and other incentives flow to owners compared with leases and PPAs.
Other Massachusetts solar incentives
Whichever production incentive you choose, Massachusetts homeowners who own their systems can also claim a state income tax credit of 15% of the cost, up to $1,000, and a 20-year exemption from local property tax on the system. See all of the current programs on our Massachusetts solar incentives page.