As part of the Biogas atlas R&D project, future focus areas were pinpointed for the cultivation of energy crops for biogas production, taking into account the requirements of water protection and the production of fermentation residues and the quality of these residues (pollutants). Exclusion zones for the production of fermentation residues were also shown, or areas with require specific consideration in the event of a change to agricultural use for energy crop cultivation.
Areas that are not suitable for receiving fermentation residues from TZW’s perspective were identified (exclusion zones). These include arable land within riparian strips, areas within the protection zones I and II of water conservation areas or areas that lie within the 50-day line of water catchment plants. Other areas that are important to the water industry are subject to restrictions, for example, the type of fermentation residue.
Based on the different restrictions and the prevailing nitrate pollution of many bodies of groundwater, further expansion of biogas generation is only possible for sustainability reasons if it can be ensured that the mineral fertilisers used at present are largely replaced by fermentation residues and appropriately factored in as part of the fertilisation calculation. This especially applies to those areas that already contain high volumes of agricultural fertilisers.
The biogas atlas provides a decision-making aid for political and industrial stakeholders to find the ideal locations for feeding biomethane into the gas grid and thereby protect the waterbodies in the further development of bioenergy.