Corporate Best Practices for High-Quality EAC Procurement

For companies committed to renewable energy and reducing Scope 2 emissions, Energy Attribute Certificates (EACs) are a key tool. They are often interchangeably referred to as Renewable Energy Certificates (RECs). The Greenhouse Gas Protocol (GHGP) provides the foundation for credible EAC use, with clear criteria to prevent double counting, ensure accurate emissions claims, and align procurement with electricity consumption.

Beyond that, different frameworks and voluntary standards add layers of verification, sustainability requirements, and best practices that shape what it means to buy “high-quality” EACs.

This blog breaks down the core principles all systems follow, key differences between standards, and what leading companies are doing to maximize the integrity of their renewable energy purchases.

What Do All EAC Standards Agree On?

The Greenhouse Gas Protocol Scope 2 Guidance defines eight Quality Criteria. These criteria set a baseline for credibility. They closely align with the rules embedded in certificate systems like GOs, RECs, I-RECs and others. Frameworks like CDP and RE100 explicitly reference these criteria. 

To comply with the GHG Protocol, EACs (or similar contracts) used for Scope 2 reporting must meet the following key criteria:

Criteria 1

Convey accurate emissions attributes: The certificate must represent the specific low-carbon attribute of that MWh of power, enabling the buyer to claim the corresponding emission factor. It is typically zero for renewables. If a certificate does not explicitly list an emission factor, it should nevertheless represent an exclusive claim to the renewable attribute so that no one else claims that MWh’s emissions benefit​.

All credible standards agree on the basics: one certificate per MWh.

Criteria 2

Be exclusive and not double counted: It must be the only instrument claiming the attributes of that MWh. This exclusivity is ensured by tracking/registries and by the rule that once an EAC is sold separately, the underlying power can no longer be claimed as renewable by another party​.

Regulatory systems and the GHG Protocol all enforce no double counting and auditability as non-negotiable criteria. It is universal across GHG Protocol, EU law, REC registries, Green-e, etc. They ensure an EAC represents a unit of renewable generation that no one else is claiming.

Criteria 3

Be retired on behalf of the purchaser: The EAC must be tracked and redeemed in a registry by the reporting entity or its agent​. Retirement prevents further transfer of the certificate and solidifies the claim for the buyer. Third-party audits or registry records should verify that the organization has exclusive claim to that retired EAC.

All credible standards agree on mandatory retirement to claim usage.

Criteria 4

Align with the reporting period (vintage): The generation date or vintage of the EAC should correspond as closely as possible to the period of electricity consumption being reported​. This prevents companies from using very old certificates to claim current renewable use, maintaining temporal relevance of the renewable claim.

The GHG Protocol does not specify an exact period for vintage matching, but Green-e establishes a 21-month window, allowing 6 months before or 3 months after the reporting year. CDP and RE100 align with Green-e’s guideline, generally requiring certificates to match the reporting year as closely as possible.

Criteria 5

Come from the same market boundary: EACs should be sourced from the same geographic market or grid system in which the consumption occurs​. The GHG Protocol defines “market” in terms of regulatory systems for trading certificates (often country-level or integrated regions)​.

For instance, a European GO can be used anywhere within Europe’s integrated GO system, but a GO from Europe shouldn’t be used for claims in a country that is outside that system. Similarly, a U.S. REC can cover U.S. or Canadian use (North American market), but one can’t normally buy a cheap certificate from another continent to claim against U.S. operations​.

There is strong alignment here as well. RE100 and CDP echo that, defining acceptable market boundaries. So the rule is consistent: use EACs from the same country or integrated market as consumption.

Additional criteria for special cases: The GHGP includes three more criteria addressing specific situations.

1. For utility-specific emission factors (when a power supplier provides a custom emissions factor for its mix), the utility must account for all its energy and properly subtract any sold certificates​.
2. For direct procurement (e.g. via a Power Purchase Agreement (PPA) or on-site generation), the buyer must ensure no double counting occurs (no other end-user or utility can claim that same generation)​.
3. A residual mix emissions factor (net of all claimed renewables) should be available for any unclaimed electricity in the grid​. This is more of a system-wide requirement to ensure accurate accounting for others. In practice, this means if a country or region provides a residual grid emission factor, companies should use it for any electricity for which they haven’t purchased EACs.

How Do EAC Standards Differ?

The Role of Independent Verification

Regulatory systems rely on formal registries and issuing bodies, which are often government-regulated, e.g. the AIB issues GOs in Europe, state agencies or accredited nonprofits issue RECs in the U.S.

Voluntary programs add extra layers. Green-e requires independent audits of sellers and publishes an annual verification report. EKOenergy has its own auditing to ensure criteria are met​. GHG Protocol doesn’t mandate third-party certification of EACs, but encourages using credible systems (implicitly those that have oversight).

The Role of Additionality

Here is where standards diverge more in philosophy. GHG Protocol and tracking systems are agnostic to additionality – they count any renewable MWh (old or new) as long as it’s properly tracked​.

Green-e and some national labels tilt toward additionality by requiring newer facilities (Green-e: ≤15 years old)​. RE100 doesn’t strictly require additionality for all purchases, but as a leadership initiative it pushes members towards more impactful procurement. Many RE100 members do invest in new projects or at least buy from new projects as part of their strategy. EKOenergy and D-REC are explicitly about additional impact – EKOenergy via funding new projects, D-REC by bringing new off-grid projects online​.

So, on one end of the spectrum you have the basic compliance and accounting standards with credible claims, and on the other end you have voluntary certifications that aim to maximize environmental impact and contribution to renewable expansion.

The Challenge of Sourcing

GHGP and basic EAC systems will count any eligible renewable. It is typically defined by local law, often including biomass, etc. Voluntary initiatives may add quality filters. Thus, “quality” can also mean the source of the renewable energy is environmentally sound.   
Companies concerned with reputational risk often voluntarily avoid sources seen as lower-quality (even if the certificates are valid for GHGP accounting).

For example, RE100 does not count a company’s purchase as contributing to RE100 targets if it’s from unsustainable sources. They exclude unsustainable biomass, hydropower and all nuclear. EKOenergy adds environmental sustainability criteria, especially for hydropower and bioenergy​. Green-e has its own list of eligible renewable sources and sometimes excludes older large hydro or certain types of bioenergy in specific markets.

What Are the Best Practices for Buying EACs?

Leading companies follow not only the letter of standards like GHG Protocol, but also the spirit, by adopting best practices that maximize the impact and credibility of their renewable energy procurement. Key corporate best practices include:

1. Adhering to Quality Criteria (or stricter): Companies ensure every EAC they buy meets the GHGP criteria on geography and vintage and often set internal rules that are even tighter. A best practice is to source certificates in the same country (or grid region) as consumption whenever possible, and within the same year of use​. This avoids the perception of “shopping around” for the cheapest options. If a company were to ignore these criteria, its claims might not be seen as legitimate by stakeholders or scoring agencies​.
2. Ensuring “Regulatory Surplus” and No Double Claims: Best practice buyers avoid EACs that are used for compliance. The U.S. Environmental Protection Agency EPA and others highlight that voluntary RECs should be retired separately and not applied to mandates​. This gives confidence that the company’s purchase is making a difference beyond what’s already required by law. Additionally, companies often obtain attestations from suppliers that no other claims have been made on the energy.
3. Prioritizing Additionality and New Projects: While any valid EAC enables a zero-emissions claim, sustainability leaders strive for high-impact procurement. This often means favoring options that directly contribute to new renewable capacity. PPAs or long-term contracts for new renewable projects are one way. Even when buying unbundled EACs, companies may choose those from recently built projects or those certified to have an additional impact.  
   
   For instance, many corporates prefer Green-e certified RECs or similar, because they require the source to be new and independently verified​. This addresses the criticism that simply buying old RECs doesn’t increase renewable supply. In practice, corporate buyers might pay a premium for such high-quality EACs.
4. Transparency and Auditing: Leading companies are very transparent about their renewable energy purchases. They publicly report the volume of EACs, the source (technology, location), and the standards or labels they adhere to. They may undergo third-party assurance of their renewable claims. This transparency builds trust that their EAC procurement is not just a checkbox exercise but a credible climate action. For example, companies will disclose challenges if they could not meet ideal criteria (e.g. if local EAC supply is limited) and explain how they are advocating for better options​.
5. 24/7 and Granular Matching (Emerging Practice): A cutting-edge best practice, pursued by tech leaders like Google and Microsoft, is matching renewable supply to consumption in real time (24/7 clean energy). This approach is still new but it goes beyond annual matching and involves time-based certificates (T-EACs).

Conclusion

In conclusion, market-based quality standards for EACs largely reinforce one another – they create a framework where a renewable energy claim is credible, unique, and transparently documented. The GHG Protocol’s criteria are the common thread, reflected in regulatory schemes and reporting programs. Differences emerge in the ambition level: some standards focus on minimum credibility, while others push for maximum impact and alignment with broader sustainability goals. A company looking to ensure “high-quality” EAC procurement should therefore: meet all the basic criteria (GHG Protocol’s eight points as a checklist), and then go beyond by aligning with certifications or practices that emphasize new projects, sustainable sourcing, and transparency.