Organic waste can often be used as input for biogas plants. In the biogas plant organic waste is transformed under anaerobic conditions (without oxygen) to biogas, which can be used in combined heat and power plants (CHP) to produce electricity and heat. Another common option is to upgrade the biogas to biomethane, which can be used as a vehicle fuel. Another output of the biogas plant is the digested material, called digestate. Digestate is a high-quality organic fertiliser that can be used in agriculture.

The anaerobic transformation helps reduce CO2 emissions and manage nutrients while producing a very flexible source of energy. Biogas is a very clean fuel that not only reduces the carbon dioxide emissions but also other harmful emissions when fossil fuels are substituted. If the biogas is upgraded to natural gas quality it can be injected into the natural gas grid and/or used as vehicle fuel (a renewable equivalent to CNG). Vehicles that run on biogas have the best CO2 balance of all the mobility options available today. It also causes much less NOx and particulate matter than diesel and therefore contributes to improved air quality.

The digestate can be used to substitute conventional fertilisers. Regional nutrient cycles can be closed, which means that the nutrients that are reapplied are the same that were lost from farmland via leaching and run-off and were transported into the Baltic Sea. This also reduces CO2 due to transportation of imported fertilisers and could potentially create a regional value chain.

The image shows the value chain for biogas as described in the text.