The continuously changing and developing technology framework and IT infrastructure create novel approaches and possibilities all over the industry spectrum. Thus the energy and its IT supporting segment cannot be an exception either. Nowadays it is hard to imagine any kind of work process on energy generation, transmission, distribution or consumption filed without IT application solutions. To keep this portfolio transparent and effective a methodology is needed for developments and strategy planning. In this paper enterprise application landscape planning experiences and recommendations are introduced. The approach effectively combines the TOGAF (The Open Group Architecture Framework) and Agile methods. At the end of a five years 'journey', the evolution can be followed from a target architecture planning approach to a novel solution which is in use right now. To conclude this work a group of techniques and methods are suggested for the application of these solutions for a sustainable and forward-looking application portfolio at a reasonable cost level.