The overall aim of the project is to assess and identify pathways towards sustainable energy systems in the Kattegat-Skagerrak (KASK) region. The focus of the project is to identify opportunities and challenges in transforming the energy system with in-depth analysis of energy efficiency measures in the industry, how the existing building stock can be made more efficient and what are the possibilities for large scale integration of wind power considering geographical allocation, investments in new cross border transmission capacity and with respect to the regional wind power as part of the North European electricity system. The in-depth analysis together with an overall establishment of how the entire energy system can be transformed will provide proposal for how the energy system can be transformed on short (2015), intermediate (2020) and long term (beyond 2030). Thus, the project will face the challenge on how short term actions can be linked to long term visions.The methodology will combine an establishment of a database of the current energy system of the ÖKS region with modeling and analysis to evaluate different efficiency measures on selected industries and on the existing building stock as well as to model the implications of large scale wind power integration. The database will be created based on existing databases (e.g. the Chalmers Energy Infrastructure Database, Sample buildings developed in other projects on the European building stock). Then, a so called Reference Energy System (RES) will be created which structure the KASK energy system in supply divided into energy carriers- conversion systems – end-use structure will be established. Together with the results from the in-depth analysis of efficiency and wind integration, the RES system will be used to assess pathways for transforming the energy system of the region. One or more pathways will be proposed, not as a prediction of the future, but to illustrate conditions and challenges for transforming the energy system to comply with regional, national and EU targets on sustainable development (focus on climate-change targets).The results will be communicated and discussed with relevant stakeholders in industry, in the political framework (municipalities, national governments and EU) and in the research community. The aim is to create a knowledge platform which can facilitate a continued and enhanced work towards a sustainable energy system in the KASK region.The work is organized in seven work packages, including project management and communication.The bulk of the work will be carried out by Chalmers (Sweden) and Tel-Tek (Norway).