The aim of this proposal is to demonstrate high-efficient polygeneration of electricity, heat, solid fuels and high-value compost/ fertilisers from sewage sludge and greenery waste mixed to biomass residues, thereby offering a new, safe, environmentally friendly and cost-effective path for the disposal of sewage sludge, maximising energy output, greenhouse gas reduction, cost-effectiveness and new chances for SME. Compared to the existing routes of sewage sludge treatment, the proposed concept allows achieving a very high overall energy efficiency by (1) use of low-temperature environmental heat and heat from the co-composting process for drying sewage sludge thereby replacing high temperature heat from a combustion process, (2) a highly efficient gasification process, (3) saving of transport energy due to a better overall material flow management. Thus, the concept brings down disposal costs of sewage sludge. The polygeneration demonstration plant will be set up on an existing compost production facility. The latter will be able to process larger amounts of sewage sludge than at present, to produce less but higher quality compost as well as pellets and/or briquettes as storable substitute fuel and to deliver electricity to the grid. Heat will be used on site for drying processes and for a district heating grid of a neighbouring industrial park. CO2 emissions are reduced by replacement of fossil fuels and directly in the composting process. Minerals and nutrients will be recovered from the ash and used to enhance the fertilising value of the compost after removal of heavy metals and other harmful fractions. 5 out of the 8 consortium partners are SME. The exploitation plan includes the creation of a two further SME for heat delivery and worldwide planning and marketing of similar plants. Replication of the concept in the 3,000 compost plants in the EU would allow additional generation of at least 56 TWh of electricity, heat and solid fuels.