# Blockchain-based Green Hydrogen Certification

> A pilot project for blockchain-based certification of green hydrogen at Nobian's chlor-alkali electrolysis plant in Bitterfeld enables complete traceability of electricity sources and CO₂ balance along the entire value chain. The system automatically captures and documents the origin of used energy and sustainability criteria of hydrogen production through a decentralized database. This solution allows producers and consumers of hydrogen to transparently and tamper-proof verify its green properties.

**Sector:** Tertiary sector · **Industry:** Renewable energy · **Organisation:** Nobian, Siemens Energy, envia THERM GmbH · **Maturity level:** Pilot

Canonical URL: https://www.sapientblock.com/en/use-cases/nobian-gruenen-wasserstoff-zertifiziert-nachweisen

## Documentation status

- **Project status:** Pilot
- **Evidence:** Evidence high
- **Editorial review:** Ufuk Avci, 15 April 2026

## Description

CertaLink is a blockchain-based certification platform for green hydrogen and e-fuels, operated by dena, Siemens Energy and TÜV Süd. Nobian tested CertaLink from 2023 at its chlor-alkali electrolysis plant in Bitterfeld (Germany). The system maps the entire RFNBO value chain and enables seamless proof of the EU simultaneity requirement: production of renewable electricity and green hydrogen must correlate hourly.

Nobian, formed from the spin-off of the chlor-alkali division of Nouryon, is one of the largest European producers of chlorine-based chemicals and certified green hydrogen. Chlor-alkali electrolysis simultaneously produces chlorine, caustic soda and hydrogen — using exclusively renewable energy results in certified green hydrogen with a 90% lower CO₂ footprint than fossil hydrogen. Bitterfeld has been the first certified chlor-alkali plant for green hydrogen in Germany since 2021 (up to 2,700 t/year). Nobian’s Rotterdam site was the first large (>100 MW) European producer to receive ISCC-EU-RFNBO certification (14,000 t/year, equivalent to 140 MW electrolyser). CertaLink maps the entire value chain blockchain-based: dena operates a blockchain node, verifies data before recording on the blockchain and provides first-level support. Additional CertaLink pilot project since 2022: HIF Haru Oni demonstration plant for green e-fuel in Chile.

## Benefits

- Companies can meet regulatory requirements more efficiently and differentiate themselves competitively through transparent sustainability evidence.
- Tamper-proof and transparent tracking of hydrogen origin builds trust in green certifications.
- Automated data collection and processing reduces manual errors and efforts in certification.
- Enables premium prices for demonstrably sustainable hydrogen and new business models.
- Employees benefit from automated certification processes that reduce manual documentation and improve data quality.

## Challenges

- High implementation costs and technical complexity can deter smaller companies from adoption.
- Integration of various IoT systems and existing ERP landscapes requires significant technical effort and expertise.
- Regulatory frameworks for blockchain-based certificates still need to be developed and adapted.
- Employees must develop new digital skills in handling blockchain-based certification systems.

## Technology foundation

The system is based on Siemens Energy's CertaLink™ Energy Certification platform, which uses blockchain technology to immutably store production data. IoT sensors continuously collect data on the origin of electricity and production processes, which are then transferred to the blockchain via API interfaces.

## Sources

- [Blockchain-Pilotprojekt für grünen Wasserstoff](https://www.nobian.com/de-de/nachhaltigkeit/fallstudien/blockchain-pilotprojekt)
- [Blockchain-Pilotlösung für die Zertifizierung von grünem Wasserstoff](https://www.nobian.com/de-de/aktuelles/blockchain-pilotlosung-fur-die-zertifizierung-von-grunem-wasserstoff)
- [Gesicherte Nachhaltigkeit entlang der Wertschöpfungskette](https://www.hypos-germany.de/gesicherte-nachhaltigkeit-entlang-der-wertschoepfungskette-nobian-testet-certalinktm-energy-certification-fuer-gruenen-wasserstoff/)
- [Nobian sets up blockchain solution pilot for certification of green hydrogen](https://eurochlor.org/library/news-press-releases/)