GEG Biomethane: Certified Renewable Gas for German Heating
Around 49% of Germany's residential heating systems run on gas (BDEW, 2022). The Building Energy Act sets a clear direction: rising renewable quotas from 2029, reaching 60% by 2040. Certified biomethane is the most accessible route — it works through the existing gas grid, without new infrastructure. BioGem Express structures the supply and documentation to make it work.
What does the GEG mean for gas heating?
The Gebäudeenergiegesetz (GEG) — Germany's Building Energy Act — entered into force on 1 January 2024 with a central requirement: new heating systems must generate at least 65% of their heat from renewable energy. Gas boilers were not banned. They remain a permitted option, but with a catch: operators must progressively increase the share of biomethane or hydrogen in their supply, starting from 2029.
The quota structure is straightforward. From 2029, gas heating systems outside designated heat planning zones must source at least 15% of their heat from biomethane or hydrogen. That rises to 30% in 2035 and 60% in 2040, according to the IEA's policy overview of GEG. With around 49% of Germany's residential heating stock currently gas-based (BDEW, 2022), the scale of the demand signal is real — and it's building fast.
Biomethane qualifies under the GEG on a mass-balance basis: certified volumes injected into the gas grid can be attributed to any connected consumption point, without physical delivery to the specific building. That makes European-sourced certified biomethane directly GEG-relevant — and it's what BioGem Express supplies.
How biomethane meets GEG obligations
Biomethane doesn't need to be physically delivered to your boiler. It enters the gas grid certified, moves through the mass-balance system, and is contractually attributed to your building's consumption.
Certified at the source
Biomethane is produced from organic feedstocks — residues, manure, biowaste — upgraded to natural gas quality, and certified under a recognised RED voluntary scheme such as ISCC EU or REDcert EU. GHG savings must meet the applicable threshold — at least 80% for installations from 2026 onwards. Feedstock origin and chain-of-custody are documented throughout.
Tracked through the grid
Certified biomethane is injected into the gas grid and tracked via a mass-balance system covering the full supply chain — from production to injection, transport, and extraction — as required by §22 Abs. 1 Nr. 2d GEG. The certified attributes follow the contractual allocation: your building receives the GEG-compliant share, not necessarily the specific molecules produced at the origin site.
Quota obligation met
The building operator or gas supplier demonstrates the certified renewable share through documentation — sustainability proof, mass-balance records, and contract evidence. This covers the GEG quota requirement for the relevant year. Where a building is also subject to BEHG or EU ETS obligations, the same certified supply can be structured to address multiple compliance frameworks simultaneously.
Four things that need to be right
Not all biomethane qualifies under GEG — and simply holding a green gas tariff is not enough. Only 42 of 189 biogas tariffs available in Germany in 2025 fully met GEG requirements (Verivox, 2025).
RED sustainability certification
Biomethane used under GEG must be certified under a recognised RED voluntary scheme — ISCC EU or REDcert EU being the most common. For installations from 2026, the minimum GHG reduction threshold is 80% against the fossil reference value. The certification covers feedstock eligibility, production pathway, and GHG intensity, and must be maintained by all parties in the supply chain.
Full mass-balance chain (§22 GEG)
GEG requires mass-balance accounting across the entire supply path: from production through injection, transport in the gas grid, and extraction at the point of use. This rules out simple book-and-claim GoOs as the sole GEG compliance instrument. The documentation chain must be intact from producer to building, with no gaps in traceability. BioGem Express manages this chain on behalf of buyers.
Feedstock eligibility
GEG sets a feedstock cap for new plants: installations from January 2024 may use no more than 40% cereals or maize in a calendar year (§71f GEG). In practice, the strongest GEG-compliant volumes come from residues, manure, and biowaste — which also deliver the highest GHG reduction values and often carry a premium in compliance-driven markets. Manure-based pathways can in some cases reach near-zero or negative GHG values.
Heat planning alignment
The GEG quota timeline depends partly on whether a building sits within a designated municipal heat planning zone. Cities above 100,000 inhabitants must complete heat planning by June 2026; smaller municipalities by June 2028. Buildings in zones designated as district heating or hydrogen network areas face different requirements. Knowing your building's status matters for structuring the right supply timeline.
Your GEG biomethane partner
Getting biomethane right for GEG compliance isn't just a sourcing question. It's a documentation, certification, and timing question. The supply must be in place before the quota kicks in — and the proof must hold up under scrutiny.
BioGem Express sources certified biomethane from verified European producers operating under recognised RED schemes. We structure long-term agreements that lock in supply and pricing ahead of the 2029 deadline, and we deliver the full documentation package your compliance and audit teams need — including sustainability proof, mass-balance records, and contract evidence matched to your GEG obligations.
"Energy transition shouldn't feel like a maze. We handle the complexities. You get the results — and the proof to show for it."
Vincent Crausaz — Business Developer, BioGem Express- Sourcing of GEG-compliant certified biomethane from verified European producers under ISCC EU or REDcert EU
- Full mass-balance documentation covering the supply chain from production to delivery, as required by §22 GEG
- Long-term Biomethane Purchase Agreements (BPAs) — lock in compliant supply before 2029 quotas take effect
- Compliance coverage across related frameworks: BEHG, EU ETS, and GEG — often from the same certified supply structure
- Advice on heat planning status, quota timelines, and the implications of the proposed GMG reform for your supply strategy
- Access to both residue-based and manure-based feedstock pathways for maximum GHG performance
Key questions on GEG & Biomethane
The GEG (Gebäudeenergiegesetz) is Germany's Building Energy Act, in force since 1 January 2024. It requires new heating systems to generate at least 65% of their heat from renewable energy. Gas boilers remain permitted, but must progressively run on higher shares of biomethane or hydrogen: 15% from 2029, 30% from 2035, 60% from 2040. With around 49% of Germany's residential heating stock on gas (BDEW, 2022 data), the demand signal is large and building steadily.
The first mandatory quota takes effect on 1 January 2029 for gas heating systems installed from 2024 onwards in buildings outside designated heat planning zones. The heat planning deadline for cities above 100,000 inhabitants is 30 June 2026; for smaller municipalities, 30 June 2028. Buildings in designated district heating or hydrogen network zones follow a different timeline. Knowing your municipality's status determines exactly when your obligations begin.
Biomethane qualifies under GEG when it is certified as a renewable gas under a recognised RED voluntary scheme and delivered via a full mass-balance system — from production to injection in the gas grid and extraction at the point of use, as required by §22 GEG. The certification must cover feedstock origin, GHG savings (≥80% for new installations from 2026), and chain-of-custody documentation. A Guarantee of Origin alone is not sufficient for GEG compliance.
The current GEG places the compliance obligation on building owners and operators. The proposed GMG (Gebäudemodernisierungsgesetz), presented as a key issues paper in February 2026, would shift that obligation to gas and oil suppliers — who would be required to blend rising shares of green gas from 2029, starting at 10%, fulfillable via Guarantees of Origin. The GMG is not yet law. The GEG remains in force, and any supply strategy should be built around current legal requirements, with flexibility to adapt as the reform advances.
No. Under GEG, biomethane can be used on a mass-balance basis: certified volumes injected anywhere in the gas grid are contractually attributed to consumption at any connected point, without the specific molecules physically reaching your building. This is what makes cross-border European biomethane supply GEG-relevant — and it removes the need for any new grid infrastructure on the buyer's side.
BioGem Express is a Swiss-based biomethane trading company operating across regulated European markets since 2020. We source GEG-compliant certified biomethane from verified producers, manage the full mass-balance documentation chain, and structure long-term supply agreements designed to cover your quota obligations from 2029 onwards. We also support clients with multi-framework compliance — covering BEHG, GEG, and EU ETS obligations from a single, certified supply structure.
Sources used on this page
This page is built on regulatory and market data from the German authorities and sector organisations most authoritative on GEG biomethane requirements. All data reflects the most recent available information at the time of writing.
Key figures used: 49% gas-based residential heating stock from BDEW Heizungsstruktur des Wohnungsbestands (2022 data); 13–45 TWh additional biomethane demand by 2040 and the 30 TWh mid-scenario from the dena GEG demand study (2024); the 42/189 GEG-compliant tariffs from Verivox (2025); and the GMG reform key issues paper (February 2026) from Clean Energy Wire and Bird & Bird.
EBA Annual Report 2025
- GEG policy overview Germany's Building Energy Act (GEG) — IEA Policy Overview
- Biomethane demand Biomethane Demand Based on the GEG
- German market data Biomethane Industry Barometer 2025
- GMG reform German government drops mandatory renewable share for heating
- Certification framework ISCC EU System Documents
- Heat planning law GEG Fact Sheet — German Federal Government
Ready to plan your GEG biomethane supply?
The 2029 quota is closer than it looks. Our team can assess your compliance timeline, explain the certification requirements, and structure a long-term biomethane supply agreement built around your GEG obligations — and any BEHG or ETS exposure alongside.