A Renewable Energy Certificate (REC) — called a Guarantee of Origin (GO) in Europe, or an International REC (I-REC) in emerging markets — is a market instrument that represents the environmental attributes of one megawatt-hour of electricity generated from a renewable source. Understanding how these certificates work is essential for solar project developers seeking revenue stacking, and for corporations building credible renewable energy procurement strategies.
What a REC represents
When a solar power plant generates 1 MWh of electricity, two things happen simultaneously:
- The physical electricity flows into the grid and gets mixed with power from other sources
- One REC (or equivalent certificate) is issued to the generator to represent the renewable attributes of that MWh
The REC and the physical electricity can then be sold separately. A corporate buyer that cannot physically install solar can purchase RECs from a solar generator in another location to claim that their electricity consumption is "matched" by renewable generation. This separation — physical electrons vs. attributes — is what makes RECs work as a market mechanism across a grid.
US REC market structure
In the United States, RECs are created by state-level renewable portfolio standards (RPS) and traded in either compliance markets (where utilities must buy RECs to meet RPS requirements) or voluntary markets (where corporations buy RECs for sustainability claims).
| REC type | Market | Typical price range | Tradeable? |
|---|---|---|---|
| Compliance RECs (SRECs, Class I) | State RPS compliance | $5–$300/REC depending on state | Within state or market |
| Voluntary RECs (Green-e certified) | Corporate sustainability | $1–$5/MWh (solar) | Nationally |
| Bundled RECs (with PPA) | Corporate PPAs | Embedded in PPA price | No — tied to power contract |
| Unbundled RECs | Spot/bilateral market | $1–$4/MWh | Yes — energy attribute only |
Solar RECs (SRECs) in certain states (New Jersey, Massachusetts, Maryland) trade at a premium over generic RECs because state RPS solar carve-outs create additional compliance demand specifically for solar generation.
International RECs (I-RECs)
The I-REC Standard is an international framework for issuing, tracking and redeeming renewable energy certificates in markets that lack national REC infrastructure. Currently active in over 40 countries including much of Southeast Asia, the Middle East, Latin America, Africa and parts of Eastern Europe.
For solar developers in emerging markets, I-RECs provide a revenue stream on top of electricity sales:
- A 10 MW solar plant generating ~15,000 MWh/year creates 15,000 I-RECs annually
- At $1–2/I-REC (typical voluntary market price), this represents $15,000–30,000/year of additional revenue
- Corporate buyers in countries without a national REC scheme (e.g., Vietnam, Indonesia, UAE) increasingly purchase I-RECs for Scope 2 reporting under GHG Protocol
Corporate use cases: RE100, CDP, Scope 2 accounting
The main corporate drivers for REC/I-REC purchases:
- RE100 commitment: companies committing to 100% renewable electricity must match consumption with certificates from the same country/region (market-based Scope 2 accounting)
- CDP A-list disclosure: Science-Based Targets Initiative (SBTi) requires Scope 2 reduction through renewable procurement — RECs count under market-based methodology
- ESG/sustainability reporting: ISO 14064, GHG Protocol, and most reporting frameworks accept RECs for Scope 2 electricity claim
Important limitation: RECs are increasingly scrutinised by environmental NGOs and sophisticated buyers who prefer 24/7 carbon-free energy (CFE) — hourly matching of consumption and renewable generation — over annual REC matching. Google's 24/7 CFE initiative and Microsoft's similar commitments are pushing the market toward more rigorous matching standards.
How to register a solar plant for REC issuance
- US: Register with a state REC tracking system (PJM-GATS, WREGIS for western US, M-RETS for midwest, NAR for national voluntary). Requires metered generation data and annual verification
- EU/UK: Apply for Guarantees of Origin (GOs) through the national issuing body (AIB member in most EU countries; Ofgem in UK)
- Emerging markets: Apply to an I-REC Standard Issuer (local accredited body) — list at irecstandard.org
Registration costs are typically modest ($100–500 one-time + $0.01–0.05/MWh annual issuance fee) but the process can take 2–6 months, so plan ahead if REC revenue is part of the project financial model.