REC Credits Explained for Massachusetts Shoppers

A homeowner in Worcester opens her electricity bill and notices a supplier offer tucked inside: "100% renewable, powered by RECs." The rate is a few cents higher than what she pays now. She almost signs up, then pauses. What exactly is a REC?

That moment of hesitation is worth honoring. The term gets used constantly in electricity marketing, but the mechanics behind it are rarely explained. Once you understand how renewable energy certificates actually work, you can decide whether they belong in your purchasing decision or whether your money is better spent elsewhere.

A renewable energy certificate (REC) is a market instrument that represents the environmental attributes of one megawatt-hour (MWh) of electricity generated from a renewable source, such as wind, solar, or hydropower. When a solar farm in Massachusetts produces 1 MWh and feeds it into the grid, two things are created: the electricity itself, which blends into the regional power pool, and one REC, which can be tracked, sold, and retired separately.

The electricity and the REC do not have to travel together. A wind farm in Maine can generate power, sell that power into the New England grid, and sell the associated RECs to a utility or supplier in another state entirely. This separation is the key to understanding both the value and the limits of REC-based green energy claims.

In New England, RECs are tracked through the New England Power Pool Generation Information System (NEPOOL-GIS), a registry that issues, transfers, and retires certificates. Every certificate carries a unique identifier tied to the generating facility, the fuel type, the vintage (the month the power was generated), and whether it qualifies under a state's renewable portfolio standard.

When a supplier says a product is "100% renewable," it typically means the supplier has purchased and retired enough RECs to match the electricity volume sold to customers. The actual electrons flowing into your home still come from the same regional mix of gas, nuclear, hydro, and renewable sources. The REC is the accounting mechanism that lets you claim the environmental benefit of the clean generation, even though the grid does not physically sort electrons by source.

Massachusetts has one of the country's more structured approaches to renewables. The state's Renewable Portfolio Standard (RPS), overseen by the Massachusetts Department of Public Utilities (DPU), requires that a growing share of electricity sold in the state come from qualifying renewable sources each year.

The RPS divides RECs into tiers. Class I RECs come from newer renewable facilities and carry the most regulatory weight. Class II RECs come from older facilities or certain waste-energy sources. When a supplier advertises an RPS-compliant product, it means the RECs used meet these state standards, not just any generic certificate purchased on the open market.

This distinction matters when you compare offers. A supplier selling "100% renewable" backed by cheap out-of-region RECs that do not qualify under Massachusetts RPS is offering something meaningfully different from a product built around Massachusetts-sourced Class I certificates. The DPU's oversight gives the RPS teeth, but it does not govern voluntary green products that sit outside the standard.

If you have never switched suppliers, you are currently on your utility's Basic Service rate. As of July 2026, Eversource's Basic Service rate sits at roughly 15.6 cents per kWh and National Grid's at roughly 15.4 cents per kWh (the same rate applies to National Grid's Nantucket territory).

Basic Service already includes the utility's RPS compliance costs, meaning a portion of what you pay funds the procurement of qualifying RECs to meet the state mandate. You are not receiving zero renewable content on Basic Service. The utility is required by Massachusetts law to include a minimum renewable percentage, and that requirement is enforced through the REC system.

What Basic Service does not offer is a voluntarily higher renewable percentage, a direct relationship with a specific project, or a marketing claim of "100% renewable." Those are the distinctions competitive suppliers are selling when they pitch REC-backed products.

The lowest competitive supplier rate available in Massachusetts as of July 2026 is around 15.1 cents per kWh, though that figure varies by utility territory and changes frequently. Check Massachusetts electricity rates at ElectricRates.org for current competitive offers.

When a supplier charges a premium for a REC-backed product above the Basic Service rate, ask a few specific questions before you sign. First, what class and vintage are the RECs? Second, are they sourced from within New England, or are they generic national certificates? Third, are they retired in your name through NEPOOL-GIS, or does the supplier simply hold them on its books?

You can also compare options through Energy Switch Massachusetts, the state's official comparison site, which lists licensed competitive suppliers and their product details. Not every shopper will find a REC-heavy product worth the premium. But for households with a specific sustainability goal, knowing the quality of the certificates makes the comparison meaningful rather than just a marketing exercise.

Many Massachusetts towns have adopted Community Choice Aggregation (CCA) programs, sometimes called municipal aggregations. These programs allow a municipality to negotiate electricity supply on behalf of its residents, and many include a voluntary opt-up to a higher REC content at a modest additional cost.

CCA programs are also subject to DPU oversight and must disclose their fuel mix and REC sourcing in their disclosure labels. If your town has an active CCA, the enrollment notice you received should have described the renewable content and the class of RECs included. If you are unsure whether your town participates, your utility's website or your town's energy coordinator can confirm it.

CCA is not available everywhere in the state, and the economics vary. Some programs have come in below Basic Service rates historically, while others have not. The renewable content built into a CCA product can make the comparison more favorable if you would otherwise be paying a premium to a competitive supplier for the same certificate quality.

Massachusetts homeowners with rooftop solar generate a specific type of certificate called a Solar Renewable Energy Certificate (SREC) or, under the current incentive program, a SMART incentive credit. These instruments work on the same foundational logic as RECs but are reserved for solar generation and carry their own program rules and compensation structures.

If you generate your own solar power, you are producing both the electricity your home uses and the certificates associated with that generation. Whether you retain those certificates or sell them depends on your agreement with your installer and the incentive program you enrolled in. Confusing a retail REC purchase with the certificates a solar homeowner generates is a common source of misunderstanding; they are related concepts but operate through separate programs.

A REC credit is not a scam, but it is also not magic. It is an accounting tool that lets renewable generation be matched to retail consumption across a large, mixed grid. Massachusetts has a real regulatory framework, enforced by the DPU, that gives certain classes of RECs more credibility than others.

For most households, the practical question is whether a supplier's REC-backed product is priced competitively enough to justify the premium over Basic Service, and whether the certificates are the quality the marketing implies. Checking the supplier's electricity disclosure label, looking at REC class and source, and comparing the rate against current Basic Service figures gives you a concrete basis for that decision.

For current competitive rates across Eversource and National Grid territories, visit the Massachusetts electricity rates page at ElectricRates.org, where offers are updated as they change.