The DEBCO project responds to the need for further operational experience in high share biomass co-firing using different type of fuels. The project aim to demonstrate and assess, on a long term basis, the advanced and innovative co-firing techniques that are capable of achieving higher shares of biomass up to 50% more on a thermal basis. These objectives will be achieved through a programme of research activities, large-scale demonstrations and long-term monitoring of the key co-firing concepts. The selection of four representative demonstration sites will allow a long-term monitoring and assessment of the most relevant applications such as: different fuel supply chain scenarios, fuel qualities (agriculture residues, energy crops, wood pellets etc.), and advanced co-firing techniques of different pf-power plants burning lignite and bituminous coals. To evaluate the role of co-firing in a sustainable energy market, social-economical aspects such as impact on local fuel markets are also in the focus of the project. The successful outcome to the DEBCO project will provide the electricity supply industry in Europe with very valuable, and well documented, plant experience on a number of the key technical options available for increasing the share of biomass co-firing in large coal-fired power plants, and for the diversification of the range of biomass feedstock types that can be co-fired. This experience will be relevant for future co-firing projects involving both the retrofit of existing plants and for advanced coal-fired power plants. This will assist the ongoing efforts in most European countries to increase the portion of electricity supplied from renewable sources.