Biogas comes from the biological breakdown or fermentation of organic matter such as household waste, sludge from treatment plants, and effluent from agriculture and the food-processing industry in an oxygen-free environment. Biogas is a lean gas with around 50% methane content. It is also considered a source of renewable energy.

Biogas can be used in three key ways:

  • It can be burned in a boiler to provide hot water.
  • It can provide heat and electricity through cogeneration.
  • It can be treated and fed into the gas network, in which case it is commonly referred to as "biomethane".

Biogas can be used as an energy source to unlock the energy potential contained in organic matter while treating and returning the same organic matter to the soil through anaerobic digestion. This makes biogas a key component of the circular economy.