Life cycle costing of energy storage technologies for building integration

In the context of the Energy Performance of Buildings Directive (EPBD), buildings will have to serve both as "energy producers", "energy consumers" and "energy storage units" in the near future. Efficient buffering of time-related differences between production and consumption of thermal and electrical energy will not only play a major role on district but also on building level. Therefore technologies for energy storage, which can be integrated into buildings in an economic way, are necessary. Within the European project MESSIB ("Multi-Source Energy Storage System Integrated in Buildings") new technologies for thermal and electrical energy storage are developed, assessed and demonstrated. In addition to the technical feasibility an important issue of the project is the economic assessment which is conducted by means of Life Cycle Costing (LCC) based on technical scenarios. Life Cycle Costing is a method to identify the total costs that occur during the whole lifetime of a product or system. Within MESSIB it will be addressed by using different calculation methods such as dynamic amortisation, retrograde calculations or net present value (NPV). The presentation will focus on the general approach for conducting LCC assessments of building integrated energy storage systems, demonstrated on the example of a vanadium redox flow battery (electrical storage technology). Emphasis will be given to the methodology of a life cycle based approach and the evaluation of potential cost savings within the operation phase of the technologies. For this purpose, several scenarios are defined, wherein both technical and economic parameters vary. Energetic benefits of the storage technologies are determined by analysing the building energy demand and potential reductions as well as operation strategies to minimize the amount of energy taken from the public grid. This allows for discussing on economic advantages and disadvantages of such energy storage technologies depending on various future conditions and developments.