Sonderborg´s ProjectZero project is focused on creating a ZEROcarbon Sonderborg-territory by 2029 by a full-scale demonstration of an integrated energy system in Sonderborg. Since its creation in 2020, a 51.7% CO2-reduction have been achieved – and the new Masterplan2029, approved by the Sonderborg City Council by the end of 2021, co-created by almost 100 local experts and stakeholders has defined the most cost-efficient way to achieve Sonderborg´s ZEROcarbon (neutrality) ambition by 2029. ProjectZero is based on a public-private partnership between the municipality, the Danfoss-foundation, local /regional utility companies, the SDU Southern Denmark University supported (when created) by the Nordea national bank foundation and the DONG Energy national energy company.