Conducting conjugated polymers and biopolymers such as nanocellulose and ligning represent the material of choice for the majority of applications for organic- and bioelectronics. This is because many polymers have excellent thermal and air stability, high electrical conductivity, and well-developed and relatively simple synthesis technology that allows a large-scale manufacturing including printing. They are also biocompatible and open for transport of biologically active ions. Recently, novel cellulose-polymer composites and lignin-based materials demonstrated their potential for effective energy storage applications. Computational studies of these materials are in critical demand because the lack of theoretical understanding of their material properties represents the major obstacle for further improvement of the device performance and material functionality. The aim of the proposal is to perform Quantum-Mechanical and Molecular Dynamics studies of conducting polymers and composite cellulose materials, as well as to model devices based on these materials to answer fundamental questions concerning the electronic structure, morphology, charge carrier transport, as well as to explore their potential for energy generation and storage. A crucial aspect of this project is that our research provides guidance to the experimental activities of the Laboratory of Organic Electronics at Linköping University, as well as to other research groups in Sweden (at Chalmers, KTH and Stockholm Univ.). The present project is supported by multiple funding sources: KAW (Knut och Alice Wallenberg Stiftelse), EU, Wallenberg Wood Science Center, WALP (Wallenberg launchpad), Digital Cellulose Center and others. The computational time is intended for the whole group of Theory and Modelling at the Laboratory of Organic Electronics, Linköping University which currently includes 9 members (1 professor, 1 assistant professor, 1 senior scientist, 4 postdocs, 2 PhD students), all of whom are heavily involved in large-scale calculations.