- Additionality
- The principle that a purchase helps finance new renewable capacity rather than reallocating existing supply. Additionality RECs are structured to prove this and often trade at a premium.
- Alternative Compliance Payment (ACP)
- A payment a utility or supplier makes when it does not retire enough eligible RECs to meet its renewable portfolio standard obligation.
- Bundled REC
- A REC sold together with the renewable electricity it represents, as in a power purchase agreement or a utility green tariff.
- Commercial operation date (COD)
- The date a generating facility began operating. Buyers use it to favor newer projects that demonstrate additionality, and some voluntary standards set COD thresholds.
- Compliance REC
- A REC used by a utility or energy supplier to meet a state renewable portfolio standard. Only certain classes count, and prices can exceed $20 per REC in constrained states.
- Energy Attribute Certificate (EAC)
- The global umbrella term for renewable tracking instruments such as RECs, I-RECs and Guarantees of Origin. Each represents 1 MWh of renewable generation, and EACs are recognized under the GHG Protocol for Scope 2 accounting.
- Evident
- An accredited registry for I-RECs and Peace RECs that handles issuance, tracking and cross-border transfers.
- Green-e
- A voluntary certification that requires strict verification of a REC's vintage, ownership and retirement. Green-e only accepts vintages within 21 months.
- Guarantee of Origin (GO)
- Europe's renewable energy certificate, created under the EU Renewable Energy Directive. Each GO certifies that 1 MWh of power came from a renewable source.
- I-REC (International REC)
- A certificate issued under the I-REC Standard in more than 50 countries that have no domestic certificate system. Unlike U.S. RECs, I-RECs can be traded across borders.
- Non-custodial registry operations
- Registry operations in which the platform never takes custody of certificates. RECs stay in the owner's own registry accounts, and the platform acts on them only with the access granted.
- Peace REC (P-REC)
- A type of I-REC issued from renewable projects in fragile and conflict-affected regions, whose revenues support peacebuilding, humanitarian objectives and energy access.
- Power purchase agreement (PPA)
- A long-term contract, often 10 to 20 years, to buy electricity and its associated RECs from a renewable project such as a wind or solar facility.
- RE100
- A global initiative of companies committed to renewable electricity. It emphasizes credible procurement and facility age, and expects RECs to align with reporting years.
- REC registry
- The official system that issues, tracks, transfers and retires RECs, preventing double counting. A REC's registry can decide which markets or compliance programs it qualifies for.
- Renewable Energy Certificate (REC)
- A certificate representing the environmental attributes of one megawatt-hour of renewable electricity. Because electrons on the grid cannot be told apart, the REC is the legal proof that power came from a renewable source.
- Renewable portfolio standard (RPS)
- A state policy requiring utilities to source part of their electricity from renewable generation, met by purchasing and retiring RECs.
- Retirement
- Permanently recording a REC as used in the registry that issued it. Retirement proves exclusive ownership and prevents double counting, and it is what makes a renewable claim count.
- RPS class (tier)
- A state's category for RECs based on technology and generation attributes. Compliance programs accept only certain classes, so not all RECs are interchangeable.
- Scope 2 emissions
- Indirect emissions from the electricity a company buys. Under the GHG Protocol, companies use RECs and other EACs to report renewable electricity use.
- Self-supply
- Generating your own renewable electricity, on-site or through projects you own or operate, and keeping the RECs it produces.
- Transfer
- Moving RECs from one registry account to another, for example from a seller to a buyer when a trade is delivered.
- Unbundled REC
- A REC bought separately from the electricity it represents, letting a buyer match its grid electricity use with renewable generation elsewhere, regardless of its supplier or location.
- U.S. REC registries
- Regional tracking systems that issue and track RECs, such as WREGIS in the West, M-RETS in the Midwest, NEPOOL GIS in the Northeast, PJM-GATS, NYGATS and ERCOT.
- Utility green tariff
- A regulator-approved utility program that lets customers buy bundled renewable electricity from designated projects, common in regulated markets where PPAs aren't available.
- Vintage
- The date the renewable electricity behind a REC was generated. Voluntary frameworks limit acceptable vintages, so a REC outside the window won't count toward targets.
- Virtual PPA (VPPA)
- A financial power purchase agreement in which the project sells its power into the wholesale market and the buyer receives the RECs without taking delivery of electricity.
- Voluntary REC
- A REC bought by a company to back renewable electricity claims, such as Scope 2 reporting under the GHG Protocol or RE100, rather than to meet a legal obligation.
