An emissions trading system is a price signal and an accounting and enforcement system in one. You need to set a cap, allocate rights to emit, track who holds them, require their surrender when emissions occur, and enforce the rules when they are not. SPARC does not replace any of that. What it addresses is the contract-performance layer underneath it: the problem of making those obligations operationally effective inside a power sector built on long-term coal contracts.
The theory is clean. The power sector in Thailand, the Philippines, or Vietnam is not.
Power generation in this region runs on long-term PPAs that typically span twenty to thirty years. The contracts were designed for a world in which a coal plant built, fueled, and operated its own capacity. Emission responsibility, dispatch authority, payment entitlement, and delivery obligation are not written as separate things. They are fused together in a single contractual structure, and unraveling them is not something an ETS can do just by setting a carbon price.
That creates a genuine implementation problem. A government that wants to bring its power sector inside an ETS faces a specific question it usually cannot answer with standard ETS design tools: who actually holds the emission right when the plant runs under a long-term PPA, and how do you enforce surrender while preserving the contract's delivery and settlement logic?
Why PPAs resist standard ETS logic
In a well-functioning ETS, the regulated entity holds allowances, burns fuel, emits, and surrenders. The accounting is clean because one entity controls the entire chain from combustion to compliance.
A PPA-bound coal plant does not work that way. The plant generates because a contract obliges it to. It is often paid whether or not it runs, through capacity charges designed to recover fixed costs over the life of the asset. The fuel cost and variable operating cost are real, but the fundamental dispatch logic is contractual, not commercial in the usual sense. The plant's generation profile over its remaining term is largely predetermined by take-or-pay or must-run provisions that were negotiated years or decades ago.
Imposing a carbon price on top of this structure can make coal generation more expensive, but does not by itself create a practical substitution pathway inside the existing PPA structure. Depending on contract terms, the plant may pass the cost through or absorb it. In neither case does the contractual generation volume respond in proportion to the price signal. The ETS adds a compliance layer without necessarily changing what gets dispatched.
The problem is that the contract was never designed to allow emission responsibility to travel separately from the delivery obligation.
This is a practical reason why power sector ETS coverage in emerging markets tends to lag behind the headline commitment. It is not only a question of political will. The contractual infrastructure of the sector was never designed to accommodate the separation of emission rights from energy delivery rights. An ETS can impose a formal compliance obligation on the power sector without this separation, as Indonesia and Vietnam have shown. What it struggles to do is make that obligation operationally effective. Without a mechanism linking emission rights to delivery bands, payment flows, and metered dispatch, the cap can become an accounting layer that sits above the sector's actual generation behavior rather than shaping it.
What the separation actually requires
For an ETS to drive verified coal-to-clean substitution inside long-term PPAs, four things need to become separately trackable: the right to emit, the right to deliver energy under the contract, the payment entitlement, and the operational delivery obligation itself.
Right now, all four are bundled in a single instrument: the PPA. Separating them requires a layer of infrastructure that sits between the PPA and the dispatch event. That layer needs to be legally recognized, registry-backed, and compatible with both the PPA terms and the existing grid rules. It also needs to work without making full PPA renegotiation or plant retirement the starting point.
This is precisely what SPARC is designed to do.
A SPARC stream is a registered delivery band inside an existing coal PPA. When a coal operator establishes a SPARC stream, the delivery obligation for that band, the payment entitlement, and the embedded emission right all become separately trackable objects in a registry. The coal operator remains the PPA counterparty. The underlying PPA is the legal foundation and does not need to be terminated or bought out; SPARC streams require registration and the consent of relevant parties, and are subject to applicable regulatory treatment. The stream is a defined, registered structure that can be assigned to a renewable operator, tracked through metering, and connected to emission accounting.
A registered basket of rights and obligations attached to a defined delivery band inside an existing coal PPA. It carries the right to supply power under the band, the right to receive the associated payment, and the embedded right to emit carbon, along with corresponding delivery and availability obligations. Individual SPARCs arise only from delivered and metered MWh.
The emission right embedded in the stream is derived from the originating coal plant's approved emission factor, an approved benchmark, an ETS allocation, or another host-country-recognized method under the SPARC product code. It is not a generic project baseline invented for the purpose. It is anchored in a specific registered contract, delivery band, and approved emissions parameter, and tracked at the delivery-band and MWh level.
SPARC as ETS infrastructure
For a government building an ETS in a PPA-heavy power sector, SPARC adds a layer that standard cap-and-trade design does not usually provide on its own: a way to bring long-term coal contracts inside the system without tearing them up.
The relationship between SPARC and a formal ETS is not binary. It operates across three stages, each useful in its own right.
Before a formal ETS exists, SPARC streams can identify coal-backed delivery bands, assign embedded emission rights under host-country recognition, and record what happens when renewable generation fulfills those bands. The registry records produced at this stage are real evidence of lower-emission fulfillment of coal-backed delivery bands, even if no cap-and-trade system has yet been enacted.
While an ETS is being designed, that evidence becomes directly useful to regulators. Metered delivery records, verified dispatch outcomes, and registry-documented emission rights give allocation designers and MRV architects real-world data to work with rather than modeled projections. A pilot covering one or two coal operators can generate exactly the kind of accountability trail that ETS calibration depends on.
Inside a live ETS, the integration deepens. The coal plant holds or purchases emission allowances in the normal compliance way. Those allowances are reflected in the embedded emission rights of the registered SPARC streams corresponding to the plant's contracted production profile. When a renewable operator fulfills a SPARC stream and delivers lower-emission MWh, the SPARC record documents that the band was fulfilled under the stream. The ARC records the unused portion of the embedded emission right. What the government does with that unused right is a sovereign decision under its ETS framework: it may cancel the right, which can tighten the covered emissions path where the ETS or accounting framework recognizes that treatment; retain it for domestic climate accounting; apply it toward the country's NDC; or, where the government chooses, authorize selected ARCs for international transfer under Article 6.2.
That last option is where international climate finance enters the picture.
Article 6.2 and the financing question
Article 6.2 of the Paris Agreement is designed to allow voluntary cooperation between countries through internationally transferred mitigation outcomes. The UNFCCC describes it as a mechanism through which host countries can receive investment, capacity-building support, and technology access in exchange for transferring verified mitigation outcomes to acquiring countries or entities.
An ARC issued under a SPARC-enabled framework is structurally well suited to this pathway. It does not rest on a broad project-level counterfactual. It is a verified record of an approved emissions entitlement tied to a registered PPA stream, measured against the fact that renewable generation fulfilled the delivery band instead. The accounting chain runs from the original PPA, through the registered SPARC stream, through metered delivery, to the ARC. Every link is documented.
Where a host government authorizes selected ARCs for international transfer and applies the required accounting treatment, ARCs may become legible to international buyers precisely because the accounting chain is complete: a specific coal-backed delivery band, a delivered lower-emission MWh, and a recorded unused emission right. International transfer is not automatic. It requires host-country authorization, registry controls, and applicable no-double-counting safeguards.
On corresponding adjustments. For an ARC to be transferred internationally under Article 6.2, the host country applies a corresponding adjustment: it reduces its own reported mitigation by the transferred amount. This is the accounting tool that prevents double counting. The host country gets investment and deploys renewable capacity. The acquiring country or entity gets a verified mitigation outcome it can count toward its own targets. Neither party counts the same tonne twice.
Compared with avoided-emissions credits that rely heavily on modeled baselines, the reference point for an ARC is not a free-standing hypothetical. It is a specific contracted MWh-equivalent, an approved emissions parameter, and a verified lower-emission delivery event.
A practical path for ETS-minded governments
For a government that wants to build a functioning power-sector ETS but is uncertain where to start, SPARC offers a sequenced entry point rather than a requirement to design the full system upfront.
A pilot covering one or two willing coal operators and a defined set of SPARC streams builds registry infrastructure, metered delivery records, and MRV-ready emission tracking before a full ETS needs to be in place. Each MWh delivered under a registered stream is validated against dispatch data, metering records, settlement data, and attribute evidence before a SPARC is created; ARC issuance follows only after verified emissions are confirmed against the embedded emission right. That sequence produces the kind of accountable, auditable record that ETS designers need: to calibrate allocation methodologies, test MRV systems, and demonstrate to regulated entities that the accounting works.
A pilot can run under existing PPA and licensing frameworks with targeted regulatory authorization. Integration with a full ETS, when it comes, depends on host-country rules governing cap, compliance, cancellation, and any authorized international transfer. The point is that the foundation is built from real operational data, not from a theoretical model.
For governments that have made NDC commitments they need to meet, that combination is compelling: verified coal displacement, contributing to the national emission path, financed in part by international buyers where host-country authorization makes that possible, without requiring plant buyout, PPA termination, or public stranded-asset compensation as the starting point.
The coal contract becomes the transition rail, not the obstacle.