Renewable Energy Certificate (REC)

A renewable energy certificate (REC) is a tradable, market-based instrument that represents the legal right to claim the environmental attributes of one megawatt-hour (MWh) of electricity generated from a renewable source, such as wind, solar, hydro or biomass, and delivered to the grid. In the United States, a REC is issued for each MWh a qualifying generator produces, and only the holder of the certificate can claim to have used that renewable electricity.

RECs exist because electricity on a shared grid cannot be traced from a particular plant to a particular customer. The certificate separates the "renewable" claim from the physical power, so the two can be sold together or apart. Equivalent instruments elsewhere include the Guarantee of Origin (GO) in the European Union and the International REC (I-REC) used in many countries in Asia, Latin America, Africa and the Middle East. Certificates are often bundled with power purchase agreements.

Imagine a village well filled by water from many sources, some clean springs and some muddy streams. Once it is in the well, nobody can say whose water came from where. So the village gives each spring owner a receipt for every bucket they pour in. Anyone who wants to say "my water came from a clean spring" has to buy one of those receipts, and each receipt can only be used once.

A REC is that receipt for electricity. A wind farm feeds power into the grid and gets one certificate per megawatt-hour. A company that buys and "retires" the certificate can say it used that much renewable electricity, even though the power reaching its offices is the same mix as everyone else's.

Each certificate is created in an electronic tracking registry, a kind of ledger, and carries a unique serial number with details such as the generator, location, technology and date of generation. In North America, registries include PJM-GATS, M-RETS, WREGIS, NEPOOL-GIS and ERCOT's system. The life cycle has three steps:

1. Issuance. The registry issues certificates to the generator based on metered output.
2. Transfer. Certificates can be sold over the counter to utilities, brokers or end users, either bundled with the electricity or "unbundled" and sold separately.
3. Retirement. When the buyer makes a claim, the certificate is retired in the registry so it cannot be sold or claimed again, which prevents double counting, much as a ledger prevents double spending.

Prices vary widely. Compliance RECs in some US states with tight solar targets, known as solar RECs or SRECs, have traded at hundreds of dollars, while unbundled voluntary RECs from large wind regions have often sold for a few dollars or less per MWh. As with other environmental commodities, prices depend on supply, demand, vintage and location.

RECs serve two broad markets:

• Compliance markets. Many US states have renewable portfolio standards requiring electricity suppliers to source a rising share of power from renewables. Suppliers show compliance by retiring RECs, and pay alternative compliance payments if they fall short.
• Voluntary markets. Companies, universities and households buy RECs to back claims of using renewable electricity, to report lower market-based Scope 2 emissions under the Greenhouse Gas Protocol's 2015 Scope 2 Guidance, and to meet commitments published in corporate responsibility reports. Programmes such as the US EPA's Green Power Partnership and the Green-e certification scheme set rules for these claims.

In the European Union, the Renewable Energy Directive (EU) 2018/2001 requires member states to issue Guarantees of Origin, each for a standard size of 1 MWh, on request from renewable producers. GOs are used mainly for disclosing the fuel mix to consumers and remain valid for 12 months after production. Cross-border transfers run through the European Energy Certificate System managed by the Association of Issuing Bodies. The United Kingdom uses Renewable Energy Guarantees of Origin (REGOs) issued by Ofgem.

The I-REC Standard, run by the I-REC Standard Foundation based in the Netherlands, provides a common framework for countries without a national system. Local issuers approved by the foundation certify generators and issue certificates under the same one-MWh unit, and companies operating globally use them to cover consumption in places such as India, Brazil, China and South Africa.

Certificate revenue can improve the economics of a renewable project and therefore its ability to raise debt, including through green bonds and project loans. Banks advising clients on decarbonisation, such as JPMorgan through its Center for Carbon Transition (CCT), have structured deals that combine power contracts and certificates. Investors analysing a company's climate claims look at how much rests on certificates, a question relevant to ESG integration, financial materiality and disclosure under frameworks descended from the Task Force on Climate-related Financial Disclosures (TCFD).

The main criticism concerns "additionality". Buying cheap unbundled certificates from an existing hydro or wind plant may not cause any new renewable capacity to be built, so critics argue such purchases let companies report emissions cuts that do not reflect real-world change, a form of greenwashing. Others point out that annual matching lets a company claim solar power for night-time use. These concerns have led some buyers to prefer long-term PPAs that finance new projects, and to explore hourly matching. The Greenhouse Gas Protocol began revising its Scope 2 guidance in 2024–2025, and proposals have included tighter time and location matching. RECs are also distinct from carbon offsets: a REC represents renewable generation, while an offset represents a tonne of emissions reduced or removed elsewhere. Companies relying on them alongside commitments under the Paris Agreement or the Net-Zero Asset Owner Alliance (NZAOA) are expected to explain the difference, and investors applying sustainable investing policies, including those based on the Sustainable Development Goals (SDGs) (Goal 7 covers clean energy), increasingly scrutinise it through corporate engagement.

• US EPA: Renewable Energy Certificates (RECs)
• I-REC Standard