Background Traffic is responsible for 28% of greenhouse gases (GHG) in Austria and for exceeding the limits of particulate matter (PM10) and nitrous dioxide (NO2). Biomass has a low GHG load but to date it only represents a small share of vehicle fuels and biodiesel has yet to solve the NOx problems. Objectives The Austrian city of Klagenfurt has constructed a power plant (heat and electricity) based on combusting gas from wood chips (a process known as pyrolysis). The main aim of the POLYWOOD project was to extend this plant by developing and constructing the world’s first large-scale plant to use part of the above gas to generate a synthetic methane-hydrogen gas or ‘hythane’ gas (the gas is more than 90% methane) called BioSNG. This prototype gas is suitable for combustion in conventional CNG vehicles without further adaption. Two high-pressure BioSNG-gas stations would store and supply the CNG vehicles in the region. In addition, the project planned to stimulate the market for CNG-vehicles and encourage individuals and companies to use BioSNG instead of diesel or petrol. The project would purchase BioSNG vehicles for the city administration and for on-demand shared-ride taxi services. The latter would demonstrate the long-term effect of BioSNG under maximum load conditions. Finally, information campaigns would play an important role in spreading the use of BioSNG. Results The project was aborted in March 2013 after the detailed planning but before the ordering of the large components. This was due to the financing problems of the company on whose site the prototype plant should have been erected. The innovative technology itself was not the reason for the abortion. It still appears very promising, but it is unclear what will happen in the future. Technical layouts and the detail calculations were made for the individual plant in Villach.