Green Proofs · Verifiable book-and-claim

Verifiable proof
for clean commodities.

Energy Web Green Proofs is a registry framework for tracking environmental commodities through complex supply chains: sustainable aviation fuel, low-carbon shipping, renewable electricity, and climate-aligned computation. It delivers the simplicity of a traditional book-and-claim registry, albeit with the verifiability of decentralized infrastructure.

The Energy Web Verified Compute Cloud transforms high-value energy and climate sectors by turning real-world events into verifiable facts with programmable compliance and cryptographic proof. Our flagship application, the SAFc Registry, accelerates the adoption of Sustainable Aviation Fuel (SAF) by utilizing a secure book-and-claim model that allows companies to issue and retire environmental attributes without taking custody of physical SAF. Similarly, Katalist drives low-carbon shipping by booking voyages that have used Sustainable Maritime Fuel and other decarbonization technologies.

See it in action → Launch a registry
Operate and/or verify book & claim registries

Engage with us to
launch verifiable attribute markets.

Build registries that make clean energy attributes and environmental claims auditable, persistent, and transferable across sectors like aviation, maritime and logistics, and emerging fuels.

01
Real-world events recorded. Production, blending, delivery, and consumption are captured as they happen.
02
Verification logic runs automatically. Rules, eligibility, and compliance checks execute without manual intervention.
03
Proofs issued immediately. Reducing paperwork and reconciliation across the market.
See it in action → Launch a registry
The book-and-claim model

One molecule,
two pathways. Tracked separately, claimed once.

When sustainable fuel is blended into the global pool or renewable electrons land on a shared grid, you can't physically follow them to a specific flight, ship, or factory. Book-and-claim decouples the environmental attribute from the physical commodity, the volume is "booked" into a registry, then later "claimed" by the buyer. Green Proofs ensures every booking and claim is independently verified, and nothing is double-counted.

Step 01 · Produce & book
Producers register
verified attributes.
A fuel producer, generator, or operator submits sustainability, custody, and third-party certification data into the registry and the registry issues digital certificates tied to that data.
Verified at issuance
  • Proof of Sustainability, Proof of Compliance, and/or Product Transfer documents
  • Worker-node consensus on issuance
  • Tamper-evident certificate hash
Step 02 · Transfer & trade
Attributes move
through the market.
Once booked, the certificate can be transferred, split into fractions, or held, independent of the physical commodity. Each move is recorded as an on-registry transaction, so the chain of custody is unbroken from production to final claim.
Carried across the market
  • Verifiable peer-to-peer transfer
  • Fractional unit splitting
  • Open API for traders & brokers
Step 03 · Claim & retire
Buyers retire,
auditors inspect.
When a buyer wants to publicly claim the environmental benefit, for Scope 1, 2, or 3 reporting, the certificate is "retired" against a specific consumption event. Worker nodes verify the buyer's balance and lock the certificate. Once retired, it cannot be reused.
Locked, inspectable, final
  • Cryptographic retirement proof
  • Public audit trail
  • Cross-jurisdiction inspectable
Why book-and-claim, this way

Three things conventional registries can't do.

Energy Web Green Proofs delivers the user experience of a traditional registry, but the architecture beneath it is decentralized, and the process automated to follow stakeholder-defined rules. That unlocks capabilities centralized databases can't match.

Property 01
Streamlined auditing
& verification.
User identities, commodities, and the rules that govern transactions are all anchored to the same decentralized substrate, so many parties can verify the data independently, without weeks of reconciliation.
Property 02
Transparent ownership
& governance.
The SAFc Registry is non-profit owned and operated. A broad multi-stakeholder board shapes its evolution. Rulebook updates, role assignments, and methodology changes are decided in the open.
Property 03
No single
administrator bottleneck.
Worker nodes, operated by independent participants, validate every retirement in accordance with the registry rulebook. The registry can scale to thousands of producers and millions of buyers across jurisdictions.
Property 04
Privacy by
cryptographic design.
Workers verify the math without ever seeing trade secrets. Pseudonymized IDs and cryptographic proofs keep production data, counterparty identities, and pricing confidential.
Reference implementations

Powering registries in
aviation, maritime, electricity & compute.

Energy Web has been a pioneer and thought leader in Green Proofs technology that leverages blockchain for provenance authentication. Our technology has been deployed to launch numerous projects and solutions, with several referenced below.

SAFc · Aviation Maritime · Katalist 24/7 Renewable Electricity Green Proofs for Bitcoin
Aviation · Live
SAFc Registry
& Avelia.
Sustainable Aviation Fuel Certificates issued, transferred, and retired. Avelia, built by Shell, Accenture, and Amex GBT on Energy Web, was one of the world's first blockchain-powered SAF book-and-claim solutions for business travel.
What it enables
  • SAF environmental attributes decoupled from physical fuel
  • Scope 1 (airline) & Scope 3 (corporate traveler) accounting
  • Double-counting prevention via unique certificate IDs
Maritime · Live
Maritime Book & Claim
& Katalist.
The Maritime Book and Claim (MBC) accounting mechanism and the Katalist platform let shippers and freight customers lower their emissions through verified sustainable-shipping claims, supporting corporate sustainability reporting and product-level emissions disclosures throughout the maritime supply chain.
What it enables
  • Sustainable shipping claims across maritime supply chains
  • Freight-customer aggregation of demand for clean fuels
  • Audit-ready evidence for product-level disclosures

Since the first public Katalist EAC retirement in Q4 2025, more than 20,700 tonnes of CO₂e have been abated across 17 retirements.

Electricity · Reference impl.
24/7 Renewable
Electricity.
Most renewable certificates are issued at monthly or annual granularity, too coarse to prove "always-on" clean energy. Green Proofs powers an hour-by-hour matching engine that pairs generation and consumption, validated by worker nodes, with custom matching logic per buyer.
What it enables
  • Hourly matching of generation & consumption
  • Buyer-defined sourcing & priority preferences
  • Granular reporting for generators & consumers
Examples
  • Foton. Energy Web supported Foton, Turkey's I-REC issuer, using EW Origin (today Energy Web Green Proofs) to develop and operate Turkey's I-REC registry and integrated marketplace platform.
  • PTT. Energy Web supported PTT Public Company Limited with EW Origin to develop and launch an I-REC marketplace platform for Thailand and Southeast Asia.
  • Hourly clean energy matching. With Shell, Elia/50Hz, Volkswagen, and SB Energy, Energy Web designed, prototyped, and tested MVPs for 24/7 hourly clean energy matching solutions.
Compute · Live
Green Proofs
for Bitcoin.
Green Proofs for Bitcoin is a transparency initiative to enable clean energy procurement by Bitcoin miners to procure, validate, and disclose their energy footprint. Miners procure clean energy following market rules and best practices for various business benefits. This unlocks voluntary demand for clean energy and the energy transition.
What it enables
  • Verified clean energy procurement
  • Independent sustainable-mining certification
  • Selective disclosure to relevant counterparties & market participants
Launch your green-commodity registry

Ready to modernize Book & Claim and carbon markets?

From sustainable fuels and renewable energy to verified carbon credits, our solutions help turn market activity into auditable, verifiable outcomes.

Launch a registry → Explore solutions
Note Green Proofs is open source, regulator-ready, and shared-governance by design. The rulebook is public, and so is the verification.