A company can state that its electricity use is “100 percent renewable” while the electrons arriving at its facilities are physically identical to every other electron on the grid. The claim rests not on physical delivery but on renewable energy certificates — accounting instruments that separate the environmental attributes of generation from the electrical energy itself. That distinction underpins the voluntary and compliance markets that shape corporate renewable procurement today.
The Accounting Problem Certificates Were Designed to Solve
Once renewable generation enters a shared transmission or distribution network, those electrons mix with electrons from natural gas, coal, nuclear and other facilities. No physical mechanism can direct a particular set of electrons to a particular buyer. This creates a problem for any company that wants to make a verifiable claim about the renewable share of its consumption.
Renewable energy certificates solve this by separating the electricity commodity from the characteristics of its generation. In most systems, a certificate represents the attributes associated with one megawatt-hour of electricity produced by an eligible renewable source. The underlying energy is sold separately, either through a power purchase agreement or into the wholesale market. The certificate can then travel independently to a buyer that never receives the electrons.
This separation emerged alongside renewable portfolio standards and voluntary green power markets as a practical way to track renewable attributes on shared grids. Many procurement claims are accounting claims, settled against the shared grid rather than through a dedicated physical connection. Where a buyer does want to tie a claim to a specific quantity of renewable generation, the certificate supplies the tracking mechanism; without it, that linkage would depend on bilateral contracts or dedicated supply, arrangements that are difficult to assemble at the scale of a large interconnected system.
What a Certificate Actually Contains
A certificate records the attributes of generated electricity. The registry entry confirms that a specific quantity of renewable electricity was generated and injected into a shared grid. Typical certificate data includes the generator’s location, fuel type, vintage, and a unique serial number. Registry systems issue, transfer and retire certificates to prevent double counting.
In many registries, the certificate does not distinguish between a solar PV system, a wind project, or a hydro facility beyond the fuel type and project details recorded in the registry entry. That uniformity allows certificates to be compared across technologies, but it also strips away locational and temporal detail unless those elements are recorded separately.
A certificate issued to a floating solar installation on a reservoir carries the same one-megawatt-hour attribute as one issued to a ground-mounted array, provided both meet registry eligibility rules. The certificate’s additional data fields determine how much locational or chronological information a buyer can recover.
How Certificates Are Bought, Traded and Retired
In a typical transaction, a renewable generator produces electricity and creates the associated certificates. The electricity may be sold through a long-term contract or into the spot market. The certificates can be sold with the electricity, in which case they are bundled, or separately, in which case they are unbundled. Corporate buyers often purchase unbundled certificates from projects located in other regions because the certificates are cheaper and easier to acquire at scale.
Once a buyer decides to use a certificate for a renewable energy claim, the certificate must be retired in the registry from which it was issued. Retirement removes it from circulation, ensuring that no other party can claim the same megawatt-hour of renewable attributes. That step converts the certificate from a tradeable instrument into an accounting claim.
The same megawatt-hour of renewable electricity appears in two marketplaces at once: as commodity energy on the wholesale market and as a certificate in a separate market. This deliberate architecture allows renewable attributes to be tracked even when physical electrons cannot be traced. It also means the certificate price can move independently of the underlying electricity price.
Voluntary and Compliance Markets Operate Under Different Logic
Voluntary certificates are bought by companies, governments and individuals that want to make renewable electricity claims. Their price is driven by corporate demand, the availability of eligible generation, and the stringency of registry standards. In some regions, voluntary certificates trade for a small fraction of the underlying electricity price; in others, scarcity or eligibility restrictions push prices higher.
Compliance certificates serve a different purpose. They are created under renewable portfolio standards or similar mandates that require electricity suppliers to procure a minimum share of renewable energy. Because the obligation is legal, compliance certificate prices can rise to reflect the penalty for noncompliance or the cost of new renewable capacity. The two markets overlap in some regions, but they operate under different obligations and price drivers.
A hydro project in a jurisdiction with a strong renewable portfolio standard may produce compliance certificates that are in high demand. The same project in a voluntary-only market may see its certificates trade at much lower prices because there is no regulatory obligation driving demand. This regional variation explains why the same certificate concept can appear either as a meaningful revenue stream or as a low-cost paper instrument depending on where it is issued.
What Corporate Buyers Are Actually Purchasing
When a company states that it used one hundred percent renewable electricity, the claim almost always means that the company retired certificates equal to its total annual consumption. It does not mean the company’s facilities received renewable electrons. At any given hour, the electricity at the company’s meter comes from the physical grid mix. The renewable generation that produced those certificates may be hundreds of kilometres away and may have generated at a different time.
Accounting standards distinguish between location-based and market-based methods for scope 2 emissions from purchased electricity. The location-based method uses the average emissions intensity of the grid where consumption occurs. The market-based method allows a company to reflect the emissions associated with its contractual purchases, including certificates. This is why a company can report lower scope 2 emissions even if its local grid remains carbon-intensive.
For most buyers, this is a legitimate reporting choice under current standards. It describes contractual matching rather than physical energy flows. The two concepts operate on different planes. Buyers that confuse them risk making claims that are technically accurate under market-based rules but misleading to external audiences.
The Limits That Matter for Serious Buyers
The main limitation is additionality. Many voluntary certificates trade at a price far below the levelized cost of building new renewable capacity. When a company purchases low-cost certificates from an existing facility, it supports that facility’s operating revenue but may not cause any new renewable capacity to be built. This is why some corporate buyers view cheap unbundled certificates as a weak instrument for supporting new deployment.
Temporal matching is a second limitation. A buyer that uses certificates from summer solar generation to cover winter electricity consumption has balanced its annual volumes on paper but has not matched its actual consumption profile. Newer approaches such as 24/7 carbon-free energy procurement attempt to align renewable generation and consumption on an hourly basis, but these require more granular tracking than conventional annual certificates provide.
Buyers that want to support new capacity often combine certificates with power purchase agreements for specific projects. A long-term contract with a new renewable project can provide both electricity and bundled certificates, linking the buyer’s claim more directly to additional renewable capacity. Even then, the claim remains contractual rather than physical unless the project is electrically connected to the buyer’s load in a meaningful way.
Why Certificates Remain Useful and What Is Changing
Certificates provide a standardized, scalable mechanism for tracking renewable attributes across large, interconnected grids. They enable voluntary markets that allow companies to express demand for renewable electricity without being constrained by the physical location of their facilities. Renewable projects can sell certificates in these markets, creating an additional revenue stream that can improve project economics.
Compliance markets use the same underlying concept, often with stricter rules. Renewable portfolio standards in many jurisdictions require load-serving entities to procure certificates or renewable electricity in proportion to their sales. These mandates have driven renewable deployment at scale, particularly where certificate prices reflect the cost of new capacity.
The direction of travel in voluntary markets points toward more granular, time-stamped certificates and stronger locational signals. Some buyers already seek time-matched certificates or hourly renewable energy products. Similar discussions are emerging for other tracked products, including green hydrogen, where guarantees of origin face the same questions about temporal and locational matching. Whether these become the standard depends on registry infrastructure, buyer willingness to pay, and the evolution of scope 2 accounting guidance. The underlying principle remains unchanged: a certificate is a tracking instrument, not a physical claim.
References
- Greenhouse Gas Protocol — Scope 2 Guidance, for the distinction between location-based and market-based scope 2 accounting methods.
- IRENA — Corporate Sourcing of Renewables, for corporate procurement mechanisms and certificate markets.
- UN 24/7 Carbon-Free Energy Compact, for the direction of travel toward time-matched renewable procurement.
