Defining low-carbon gas and renewable gas in the European Union
Working Paper
Gas definitions for the European Union: Setting thresholds to reduce life cycle greenhouse gas emissions
To achieve GHG reductions from the use of renewable and low-carbon gases, it is necessary to define the gases based on their life-cycle well-to-wheel emissions. There can be large variations in the GHG intensity of gases, even within the same production pathway, and uncertainties in some parameters used to calculate emissions could mean that some gases classified as renewable or low carbon fail to provide GHG reductions as intended. Clear definitions of renewable gas and low-carbon gas that are consistent among EU policies are needed to support the gas pathways that achieve deep decarbonization of the sector.
This study proposes definitions for renewable gas and low-carbon gas based on key parameters that impact the life-cycle GHG emissions for major gas pathways in the EU. Example key parameters include upstream methane emissions and carbon capture and storage rates for fossil pathways, and the share of renewable electricity for electrolysis hydrogen.
| ≥ 100% GHG reduction | ≥ 80% GHG reduction | < 80% GHG reduction | |
| RFNBOs, such as electrolysis hydrogen | 100% additional, renewable electricity used for electrolysis &
100% renewable electricity used for all other processes, such as hydrogen compression and methanation |
Produced using ≥ 90% additional, renewable electricity in the total process | Produced using < 90% additional renewable electricity in the total process |
| Hydrogen from fossil gas SMR+CCS | N/A | Carbon capture rate ≥ 83.5% &
Upstream methane leakage rate ≤ 0.34% |
Carbon capture rate < 83.5% &
Upstream methane leakage rate > 0.34% |
| Hydrogen from coal gasification+CCS | N/A | Carbon capture rate ≥ 94.4% | Carbon capture rate < 94.4% |
| Hydrogen from biomass gasification | From waste biomass, such as agricultural residues &
100% renewable electricity used for hydrogen compression |
From waste biomass, such as agricultural residues | From non-residual biomass, such as stemwood |
| Hydrogen from manure anaerobic digestion | ·Methane leakage from digester ≤ 4.4%
Methane leakage during upgrade ≤ 2.2% |
Methane leakage from digester ≤ 5.7%
Methane leakage during upgrade ≤ 2.85% |
Methane leakage from digester > 5.7%
Methane leakage during upgrade > 2.85% |
| Hydrogen from wastewater sludge anaerobic digestion | Methane leakage from digester ≤ 6% &
Methane leakage during upgrade ≤ 3% |
Methane leakage from digester ≤ 7.3%
Methane leakage during upgrade ≤ 3.7% |
Methane leakage from digester > 7.3%
Methane leakage during upgrade > 3.7% |
| Biomethane from manure anaerobic digestion | Methane leakage from digester ≤ 4.5%
Methane leakage during upgrade ≤ 2.25% |
Methane leakage from digester ≤ 6%
Methane leakage during upgrade ≤ 3% |
Methane leakage from digester > 6%
Methane leakage during upgrade > 3% |
| Biomethane from wastewater sludge anaerobic digestion | Methane leakage from digester ≤ 6.2%
Methane leakage during upgrade ≤ 3.1% |
Methane leakage from digester ≤ 7.6%
Methane leakage during upgrade ≤ 3.8% |
Methane leakage from digester > 7.6%
Methane leakage during upgrade > 3.8% |
| Biomethane from silage maize anaerobic digestion | N/A | N/A | Falls in this category |
