Biomethane is a type of renewable gas created from biodegradable material. It falls under the category of “Green Gas”, which also includes green hydrogen and syngas. Biomethane has the same chemical compound as natural gas, which means it can be used in the same way and transported in the same gas grid as natural gas. Biomethane is used as a direct substitute for natural gas in national grids. Green Gas Certificates enable companies to make 100% renewable gas claims and are an effective way to integrate renewable energy into a sustainability strategy.
How does it work?
Biomethane can be produced from a number of different organic materials through methods like anaerobic digestion or upgraded biogas. These are themselves derived from biomass, directly (agricultural residues, intermediary crops, green waste etc.) or indirectly (sewage sludge, manure, some biowaste).
Biomethane avoids emissions by replacing fossil fuels. During its growth, this biomass has captured a certain amount of CO2 from the atmosphere. The captured CO2 is returned to the atmosphere during the combustion of biogas or biomethane, and then captured again by the newly growing biomass. Biomethane is virtually carbon neutral and does not contribute to climate change, but the source of the feedstock may have other effects on the environment that needs to be taken into consideration when measuring sustainability. Energy crops for instance may have the negative consequence that it leads to indirect land use change (ILUC).
The EU lays down the regulatory framework for green gas certificates in The Renewable Energy Directive (REDII). The directive includes renewable biofuels, such as biomethane in the Guarantee of Origin (GO) scheme. This regulatory framework, in addition to the increased interest and the demand for documented biomethane has driven different schemes for certification of biomethane injected to the natural gas grids. Currently certificates that are issued in the UK, Denmark, Germany, the Netherlands and Austria, can be transferred across borders. Other national registries also exist for consumption in specific countries, also exist.
In the schemes, each kWh/MWh of biomethane injected to the grid is labelled electronically with a unique identifier. This identifier contains, for each kWh/MWh of gas, information about where, when and how it was produced. When consumers buy green gas, the certificate is their guarantee that the renewable claim to the gas is authentic and has not been sold to anyone else. To close the cycle and remove the given kWh of biomethane from further trading, the certificate is redeemed in its respective registry.
Similarly, in the US, the Environmental Protection agency (EPA) and the California Air Resource Board (CARB) are working to forward the use of certificates of gaseous energy carriers.
In the EU the growth in biomethane is expected to accelerate, as the EU doubles their production targets of biomethane to be produced by the end of the year, through the EU’s REPower EU program.
Green Gas Certificates are recognized Energy Attribute Certificates (EAC). They are market-based instruments, which can help consumers make 100% renewable gas claims and report reduced Scope 1 and market-based Scope 2 GHG emissions.