There’s more than one way to buy renewable energy. If your electricity comes from the grid, you can’t separate green from grey – but energy attribute certificates (EACs) offer a practical workaround. Called GOs (in Europe), REGOs (in the UK), and RECs (in the US), certificates let buyers claim credit for 1 megawatt‑hour (MWh) of renewable electricity delivered to the grid.
Renewable EACs are market-based instruments recognised by national energy bodies. They increasingly support granular matching – even down to 24/7 hourly alignment between generation and consumption. This guide explains how EACs work, where to get them, and how to use them in clean energy procurement.
Tl;dr
- Renewable energy attribute certificates (EACs) have emerged as a low-risk way to source renewable energy
- EACs allow corporate buyers to claim clean power, even if their electricity offtake comes from a local grid
- By proving that a traceable and verifiable volume of clean energy has been purchased at the source, these certificates back up claims that a firm is advancing its net zero commitments
- EACs provide additional revenue for energy sellers and send demand signals for more renewable to be built
- When EACs are 24/7 hourly-matched, the benefits are magnified as consumption is linked to generation more accurately and in a granular way
- While purchasing EACs is meant to be straightforward, there are some barriers to entry and strategic complexities to consider
Part I: Introduction to renewable certificates
What are renewable energy attribute certificates? EACs / REGOs / GOs
EACs are an established instrument for buying, verifying, and trading renewable power. Each one represents 1 megawatt-hour (MWh) of electricity generated from renewable sources; typically solar, wind, or hydro.
EACs have different names in different regions. They're called Renewable Energy Guarantees of Origin (REGOs) in the UK, Guarantees of Origin (GOs) in the EU, and Renewable Energy Certificates/Credits (RECs) in North America. Australia calls them Large-Scale Generation Certificates (LGCs). Other jurisdictions offer International Renewable Energy Certificates (I-RECs).
These are all national and regional variations, but energy attribute certificate (EAC) is the generic catch-all term.
Regardless of label, EACs contain key details (attributes) about how, where, and when the clean power was produced. They include:
- The point of origin (generation facility)
- The month in which they were generated
- The specific renewable energy technology (solar, wind)
- The rate of carbon emissions (‘zero’ for a renewable generation plant)
- A stamp of authenticity from the national EAC registration body
Why do EACs matter?
EACs or RECs (renewable energy certificates) aim to increase the accountability and transparency of renewable energy production.
EACs demonstrate that an organisation has procured its power from a renewable plant despite physically off-taking it from the grid, where everything is mixed together. EACs provide verification and traceability, legitimising claims around achieving environmental goals. They also create demand signals for more renewable generation assets, like solar or wind farms, to be built.
How do renewable energy certificates work?
National regulatory agencies like Ofgem in the UK act as EAC registries. They issue certificates to clean energy producers, who are then able to sell them to their off-taking customers for a volume of power equivalent to their actual usage.
Once a buyer becomes sole owner of an EAC, they can ‘retire’ or ‘cancel’ it with the registry (the exact language depends on the jurisdiction). This indicates that the clean power has been consumed and validates their renewable energy claims. EACs can be traded multiple times, but once cancelled, they cannot be re-sold, ensuring no double-claiming of renewable power.
For example, if a buyer wants to use EACs to reduce scope 2 emissions, they would calculate their total power consumption for a given period and determine how many EACs are needed to meet their renewable energy targets. This could be the full amount of their consumption or just the portion not already covered by existing renewable contracts. After they’ve made the purchase, they cancel or retire their EACs with the registry and claim a corresponding amount of renewable electricity consumption.
EAC cancellation
After being purchased, cancelling or ‘retiring’ EACs can happen in two different ways, based on whether or not a buyer’s local registry allows corporate buyers to have their own EAC registry account (some do, others don’t).
Option 01: The buyer has an account with their EAC registry
EACs are transferred from the energy supplier’s account to the buyer’s account. The company then holds these EACs until it retires them.
Option 02: The buyer doesn't have an EAC registry account
A broker or supplier retires the EACs in their own account and provides an attestation document to the buyer. This document includes the certificate type, volume, generation source, and confirmation of retirement.
Corporates must provide proof of EAC procurement and retirement to substantiate their renewable energy claims. This includes certificate serial numbers, registry details, purchase contracts, and official retirement statements to confirm alignment with reporting periods.
Bundled or unbundled EACs?
Renewable energy certificates come in two formats, bundled and unbundled:
- Unbundled EACs are sold separate from the physical supply.
- A bundled EAC is sold with the physical electricity included in the same contract:
– Physical PPAs, where both the electricity and the associated EACs originate from the same renewable asset.
– Virtual PPAs, where the electricity and EACs are purchased from the same renewable project, but the electricity may not physically reach the buyer.
– Green tariffs, where both electricity and EACs are provided by an energy supplier (utility) in a single financial transaction.
In practice, you could buy bundled EACs directly from a clean power project, or from an energy retailer (supplier) that obtains the certificates from a project on your behalf.
Unbundled EACs may also be procured from sellers or retailers. As the EAC buyer, you would take electricity from the grid as normal, then use your EACs to verify your renewable energy consumption and sustainability claims.
To make the claim, EACs would be either cancelled on your behalf by the supplier or transferred into your own EAC registry account, allowing you to cancel them yourself. The method depends on the rules of the respective market in which you are operating.
“Whether an EAC is bundled or unbundled doesn't change its environmental impact. It's just a transactional choice. Bundling can be useful, but it doesn't automatically tell you things like where or when the energy was generated, or if it actually adds new capacity to the grid.”
– JP Cerda, CEO and Co-founder @ Renewabl
For more information about unbundled EACs vs green tariffs, read our procurement business case.
How 24/7 hourly matching adds value
EACs have traditionally been sold on an annual basis, however new platforms are enabling wide adoption of hourly-matched EACs. Using real-time generation data, they provide accurate links between clean renewable energy production and consumption.
Granular certificates would provide more detailed information about renewable energy generation than current options, improving transparency and credibility.
24/7 hourly matched EACs let buyers link a specific amount of clean energy consumption with an equal volume of clean energy generation — during the same hour the electricity was used.
This is made possible through hourly time stamped energy certificates, also referred to as granular certificates (GCs). EnergyTag and other industry leaders, including Renewabl, are advocating for these time-stamped certificates to become mandatory for greater transparency.
In terms of availability, several regions have adopted granular certificates, enabling better tracking of renewable energy. For example, in Nordic countries like Denmark, Sweden, and Finland, electricity grid operators are pioneers in hourly tracking. The UK is working toward hourly certifications with its REGO system, and North America has implemented hourly RECs through platforms like PJM-GATS and M-RETS.
While registries are working towards supporting this level of granularity, we can bridge this gap at Renewabl. To validate the hourly match, GCs are created to represent each of the underlying registry EACs. These GCs are given a time stamp which can be verified by aligning the unique registry EAC IDs with the metered generation data.
Find out more about hourly matching and its impact on procurement strategies.
The benefits of EACs for buyers
Renewable energy certificates offer huge potential benefits to procurement teams and executives, helping overcome key practical barriers to achieving clean energy goals:
Stabilising markets: EACs contribute to energy system stability by improving market signals. EACs incentivise renewable energy projects and the addition of more flexibility assets like grid scale battery storage. This helps ensure clean power is generated and/or discharged when it is most needed.
Promoting investment: Renewable energy projects can leverage certificates to maximise income. Added financial security makes renewable infrastructure more attractive as an investment. Great capital inflows translate into growth and expansion of renewable energy capacity, accelerating the transition towards a low-carbon energy system.
Making green energy more traceable: Hourly-matched certificates give buyers and sellers a transparent record of energy generation by making a data-backed connection between a specific volume of clean energy and the wind or solar asset responsible for it. Greater transparency adds confidence and safeguards against exaggerated sustainability claims.
Part II: EACs, regulation, and market developments
The EU has been a leader in setting rules and standards to advance the renewables transition. Three comprehensive regulatory regimes have been enacted or are on their way to final assent. With each new iteration, EACs have played an increasingly central role.
The Renewable Energy Directive (RED III)
The Renewable Energy Directive (RED) establishes renewable energy consumption targets that must be achieved across the EU. RED III, the latest iteration, prescribes the format, content, time scale and validity of GOs. It also contains provisions that will allow regulators to intervene in the GO market if imbalances are detected.
Green Claims Directive
Sometimes called the ‘greenwashing’ directive, the Green Claims directive is written to discourage buyers from making exaggerated or unsupported statements about their sustainability efforts. Scheduled for enactment in 2028, the directive will establish a clear set of standards that make sustainability claims verifiable and comparable across the EU.
Corporate Sustainability Reporting Directive
This set of recently-adopted EU regulations requires all large buyers to make regular disclosures about their sustainability performance. The aim is to help investors, consumers, and regulators evaluate corporate progress towards decarbonization and encourage buyers to develop sustainable operations.
Each of these rulebooks include measures to track progress and verify claims about the production or consumption of renewable energy. Brussels regulators have embraced EACs (in GO form) as a primary mechanism for achieving this.
Find out more about EU regulatory frameworks for renewable energy certificat
Snapshot: EACs in Europe
The renewable energy certificate market has grown steadily in recent years, with the US in the lead and Europe close behind. The EU’s Guarantees of Origin (GO) system forms the basis of Europe’s unbundled EAC market.
GO prices have increased significantly in the past few years, with notable volatility. Seasonal hydropower output, policy uncertainty, and shifting demand all contribute to frequent swings. At the start of 2025, GO prices dropped sharply due to oversupply, weaker demand in some sectors, and seasonal effects on hydropower production.
The GO market is largely voluntary, but EU frameworks such as the Corporate Sustainability Reporting Directive (CSRD) are raising transparency expectations. The recent developments under the Greenhouse Gas Protocol (GHGP) support more traceable instruments, including hourly matched GOs or granular certificates (GCs).
EnergyTag and market participants including Renewabl have called for the rollout of granular GOs in Europe. Ireland has proposed such a framework, and Nordic countries are already testing it.
EAC national registration bodies
UK: Ofgem
France: EEX
Italy: GSE
Portugal: REN
Spain: CNMC
Germany: UBA (Umweltbundesamt)
Czechia: OTE, a.s.
Rest of of Europe: https://www.aib-net.org/facts/eecs-registries
Regional systems in the USA include: M-RETS, WREGIS, NEPOOL-GIS, PJM-GATS, NAR, and others. For added credibility, Green-e is a voluntary programme that certifies renewable energy products, ensuring they meet environmental and consumer protection standards.
Part III: Purchasing certificates – REGOs and GOs procurement strategies
Pressure is mounting for businesses to demonstrate use of renewable energy and to decarbonise their operations. However, taking account of the current context, here are some important priorities for EAC buyers in 2025.
Pressure is mounting for businesses to demonstrate use of renewable energy and to decarbonise their operations. Here is our top advice for EAC buyers in 2025.
Focus on traceability
EACs give credence to sustainability claims and help buyers avoid the reputational (and regulatory) risks of greenwashing. Key to this is traceability, or the ability to track and verify the origin of renewable energy back to a specific generation source. This prevents double counting (claiming the same renewable energy multiple times) and enables informed choices about energy consumption.
With stricter renewable energy claim regulations and the likely requirement for granular EACs (or GCs) by 2027, adjusting your procurement to improve traceability is essential.
The traceability of EACs can be impacted by the choice of procurement method:
- Buying EACs directly from a renewable energy generation project is the best option for ensuring traceability, as well as geographical and temporal matching
- If buying unbundled EACs through an intermediary like a broker or an energy utility, ensure clarity from your supplier.
EAC quality over procurement methods
Evaluate EACs based on their attributes rather than the procurement method (bundled vs unbundled).
Have your own registry account
For better transparency and control over your EACs, it’s best to manage your own registry account. This allows direct tracking of certificates, monitoring their status, and handling their retirement. By doing so, buyers reduce reliance on intermediaries and minimise risks like errors in retirement or misallocations.
Buyers can choose which registry to work with, and it’s best to prioritise those with digital capabilities. These registries offer API access for automated retrieval, data export, and real-time tracking. These features streamline integration with internal systems, improve reporting, and support effective energy procurement and sustainability reporting.
Build detailed attestation requirements into RFPs
Gather auditable documentation to ensure the credibility of RE claims. This should include unique certificate serial numbers, generation source and location details, time of generation, expiration dates, and confirmations of retirement.
Avoid last-minute procurement
Waiting until year’s end to make EAC purchases can lead to higher prices, limit the range of choices, and cause delays due to administrative bottlenecks.
Track the regulatory landscape
Evolving regulatory mandates in the EU, UK and elsewhere require close observation and an understanding of the likely form any new rules, processes, definitions and standards could take. Compliance with existing rules is vital as breaches could incur financial penalties.
Don't lose sight of cost
EACs represent an additional procurement cost and can be subject to price volatility. To mitigate the impact of market speculation and variable demand, buyers need to consider EACs in the context of their wider procurement strategy
Monitor and measure
Buyers must track total vs. renewable energy consumption and the corresponding emissions reductions to ensure progress against targets is measured accurately. This requires a consistent and rich flow of data. Energy market prices and trends should also be monitored, creating opportunities to renew contracts early if pricing is favourable.
Barriers to entry
EACs are designed to make clean energy procurement easier and less constrained by proximity to nearby plants, but there are potential barriers to entry that buyers should consider:
- Larger purchases of EACs may come with more stringent credit requirements, particularly in volatile markets
- No additionality upside. Buying EACs will not support claims of additionality, meaning they don’t directly add new renewable energy to the grid
- EACs may come with volume requirements. For example, wholesale pricing may be available for volumes of 5-10 GWh+, although smaller volumes are available but buyers will have to pay retail level rates
- Premiums for 24/7 hourly matched EACs may range from 1-5% per MWh, depending on the market and desired technology mix
- At any price, EACs represent an added cost. By pairing them with a flexible electricity contract and active risk management, or as part of a corporate PPA strategy, savings may be possible
Comparing unbundled EACs to PPAs and green tariffs
Compared to bundled green tariffs, unbundled EACs offer more flexibility, lower reputational risk, and easier tracking – especially when purchased from verified platforms offering hourly matching.
“Supply tariffs may be convenient, but not every ‘green’ tariff is as green as it looks. Buyers should assess the quality of the certificates, attempt to buy local wherever possible, and ensure the type of renewable generation technology fits the company’s consumption profile.”
– JP Cerda, CEO and Co-founder @ Renewabl
Some advanced utilities offer green tariffs with a mix of technology types, tracked with hourly precision and tailored to the buyer’s needs. This option of bundled EACs provides better coverage without the need for multiple transactions from different assets. At Renewabl, we partner with Ecotricity and Octopus Energy to offer and track these tariffs.
While unbundled GOs and REGOs can’t deliver additionality on their own, EACs are fully compliant with CDP, RE100, and SBTi requirements. Though less impactful than Power Purchase Agreements (PPAs), they are often the only viable option for buyers without the scale or credit profile to access large, long-term contracts. Unlike PPAs, unbundled EACs don’t require long-term commitments or large-scale capital expenditure.
Unbundled EACs are increasingly used to fill gaps in 24/7 carbon-free energy (CFE) strategies, providing buyers with a practical entry point into granular, verified clean power procurement.
The role of energy certificate trading platforms
EAC platforms can facilitate purchases in ways that benefit both buyers and suppliers. Renewabl Trade, the new trading platform for granular certificates, aims to increase transparency in the REC market.
Renewabl’s focus is to simplify the procurement process for hourly-matched EACs by securing traceable, hourly-stamped certificates that align to actual consumption. Our approach complements gaps in your clean energy portfolio and makes it easier to achieve renewable energy targets.
By managing procurement and streamlining the tender process, EAC trading platforms like Renewabl help renewable energy projects focus on what they do best: generating clean energy. For buyers we simplify transactional complexities and eliminate unnecessary admin. For both sides we provide data and analytics for insights that support long-term value and growth.
Better together
By addressing traceability, EACs can promote investment and strengthen regulatory compliance. Green energy certificates play a critical role in accelerating the renewables transition.
- At Renewabl, we help corporate energy buyers run tenders for hourly-matched GOs, REGOs, renewable energy Power Purchase Agreements, and green tariffs.
- We work with sellers to increase their market reach and maximise revenue. We help retailers expand portfolio supply options by facilitating utility PPA tenders.
For more information, sign up for a quick demo below.
Coming soon: dynamic hourly pricing index
Power pricing is volatile at the best of times, and renewable generation brings the added variable of intermittency. Low renewable generation in a specific timeframe will typically lead to higher prices, requiring more expensive sources to fill the gap. The knock-on effect is fewer renewable energy certificates available for those low generation hours.
As certificates move to full hourly matching, sellers will be free to move from a single annual price point to 8,760 hourly options across the year. In the very near future we could see renewable generation projects use spot market pricing as a benchmark for setting REGO and GO index prices for each hour.
Even with closer regulatory oversight, renewable energy certificates will remain a traded commodity. Sellers and buyers will ultimately set prices and determine how they are calculated.
Find out how to prepare for dynamic energy certificate pricing.
– With files from Renewabl contributor Mark de Wolf
FAQs
What is an energy attribute certificate?
An energy attribute certificate (EAC) is a tradeable instrument that verifies the green credentials of 1 MWh of generated renewable electricity
What are renewable energy credits (RECs)?
Renewable Energy Credits (RECs), also known as Energy Attribute Certificates (EACs), are tradable instruments that verify 1 MWh of renewable power was produced at a specific time and location. They allow organisations to cover a certain percent of their consumption with clean energy. RECs is the term used in the USA, while I-RECs (International Renewable Energy Certificates) are used outside of Europe and North America
Are EACs worth it?
EAC’s allow buyers to prove they purchase renewable energy in quantifiable volumes, supporting sustainability claims and regulatory reporting
What are EACs called in the EU?
In Europe, energy attribute certificates are called guarantees of origin (GOs)
What are EACs called in the UK?
In the United Kingdom, energy attribute certificates are called renewable guarantees of origin (REGOs)
What does 1 EAC equal?
Each energy attribute certificate is generated for one megawatt-hour (MWh) or electricity
What is a REC credit or renewable credit?
Renewable energy certificate (RECs) is the North American term for Energy Attribute Certificates (EACs). In Europe, EACs are called Guarantees of Origin (GOs). In the UK theye are called or Renewable Energy Guaratees of Origin (REGOs).
An REC credit is issued when one megawatt-hour (MWh) of renewable electricity is generated and fed into the grid. Buyers purchase RECs to verify consumption of green power, even without on-site generation.
What sources qualify for renewable EACs?
EACs can be generated via power plants from these renewable sources: wind, solar, moving water (hydropower), organic plant and waste material (biomass), or by using the earth's heat (geothermal). Climate Group’s latest technical criteria also recognises marine (wave and tidal) and nuclear (fission and fusion).
What is a SREC or a solar EAC?
Solar Renewable Energy Certificates (SRECs) or solar EACs are EACs issued specifically for electricity produced by solar panels.
Are EACs greenwashing?
EACs or RECs are a valid evidence of a company’s renewable energy use, recognised by many states and local governments. For example, when Budweiser’s 100% renewable electricity claim was challenged by Ireland’s ASAI, the EU upheld Guarantees of Origin under RED II as credible proof, even when electricity comes from the grid.
The environmental impact of EACs depends on how they are being procured. Some critics say EACs may reduce incentives to innovate beyond baseline compliance. But verified, plant-specific EACs can offer stronger support for clean energy than green tariffs that lack source transparency. The better the match with time and location of energy use, the more impactful the certificates.
New accounting standards under development, such as 24/7 hourly matching or 24/7 Carbon-Free Electricity (CFE), are making green certificates more traceable and better aligned with actual demand. For buyers with limited access to PPAs or on-site generation, unbundled GOs/REGOs remain the most practical tool.
What’s the difference between EACs/RECs and carbon offsets?
Carbon offsets address emissions outside the power sector while EACs apply specifically to electricity use. Both aim to reduce carbon footprint, but through different mechanisms.
Carbon credits, or offsets, compensate for greenhouse gas emissions by funding activities that remove or reduce them elsewhere. These include forest protection, methane capture, or clean cookstove projects. The impact is indirect and often delayed.
Energy attribute certificates track the generation of renewable electricity and match it with consumption.
Because grid electricity blends all sources, EACs provide verified proof of a set amount of renewable energy produced and claimed. By purchasing and then cancelling (retiring) EACs, businesses can credibly say that part of their grid electricity came from low-carbon sources. Where consumption exceeds available RECs, it signals a shortfall in renewable supply – encouraging investment in more generation.
What is the environmental impact of EACs?
EACs allow buyers to track their use of clean power and its environmental benefits. High-quality EACs come from recent, unsubsidised projects with clear climate impact. They may fund new wind or solar construction and displace fossil fuels. Those traits make them credible even when sold separately from bundled deals.
Matching EACs by geography or timing strengthens their impact. Certificates sourced from local grids or purchased at the same time as electricity use send strong market signals and reduce emissions more effectively.
Finally, ecolabels such as Green‑e® and EKOenergy add extra assurance by confirming that EACs meet strict environmental standards. Yet the true climate benefit depends on the asset’s additionality, timing, and relevance to the off‑taker’s consumption.
What is an RPS?
A Renewable Portfolio Standard (RPS) is a regulatory requirement for electricity providers to source a specific percentage of energy from renewable sources like wind, solar, and hydro. The RPS helps drive renewable energy generation, reducing reliance on fossil fuels and supporting climate goals.
In some cases, providers can meet their targets by purchasing renewable energy certificates (RECs) from other suppliers who exceed the required renewable energy level.
Several countries have implemented RPS or similar systems. In the United States, California and New York have their own RPS targets. Canada, India, and South Korea have introduced national and state-level requirements. The European Union has set a regional renewable energy goal of 32% by 2030, with some countries also introducing national targets. Australia and Japan also have systems in place to encourage renewable energy adoption through similar mechanisms.
What’s a certificate arbitrage?
EAC or REC arbitrage involves the buying and selling of RECs to profit from price disparities between different markets.
