Introduction

Use of fossil fuels such as natural gas, oil, and coal are responsible for about of global greenhouse gas (GHG) emissions, and make up of GHG emissions within the energy sector. Alternative energy sources exist with far fewer GHGs emissions, but technological, economic, and administrative barriers prevent and limit their development.

Biogas is a renewable energy source that can be produced via several different pathways. One option is anaerobic digestion, where organic materials such as food waste, animal manure, and agricultural residues are broken down by microorganisms in an oxygen-free environment. Common uses of biogas include:

• Injection: Purification of biogas to biomethane and directly injecting it into the gas network.

• Cogeneration: Generation of electricity and heat by a biogas engine or turbine for a combined heat and power (CHP) system.

• Heat only: Production of heat in a biogas boiler.

• Transport: Compressed natural gas (BioCNG) and liquefied natural gas (BioLNG)

The second output of anaerobic digestion, digestate, is a material rich in organic matter and nutrients that is spread on agricultural fields.

have confirmed that using biogas from anaerobic digestion rather than energy from fossil fuels leads to reduced GHG emissions. Yet, biogas makes up a small share of energy consumption: in 2022 in Europe, more natural gas was used than biogas,.