SPIN.OFF - Integration of storage systems in the office building Tech2Base

Starting point/motivation

Up to now, battery storage systems have primarily been used in the private sector to increase the share of PV self-consumption. However, from a technical point of view, battery storage systems can provide much more contributions to a future energy supply system and thus for the grid. One option is the use of battery storage systems in commercially used buildings to reduce peak loads.
Contents and objectives: The following objectives were pursued within the research project "SPIN.OFF":

• Integration of a battery storage in an office building under consideration of planning and safety aspects
• Development of a self-learning energy management system to reduce load and generation peaks in an office building based on a self-learning artificial neuronal network (KNN)
• Energy-technical and economical evaluation of battery storage systems for grid use
• Survey of the acceptance of battery storage systems in commercially used apartment buildings / office buildings
• Evaluation of the environmental impact of grid-supported battery storage systems

Methods

To achieve these goals, a saltwater battery storage (Aqueouse Ion Exchange Technology) was integrated into the FutureBase - an office building in Vienna's 21st district. In order to gain experience with the new battery storage technology, it was first installed and measured at the Hybrid Energy Lab of the UAS Technikum Wien. In parallel, a self-learning energy management system for reducing load and generation peaks in an office building based on a self-learning artificial neuronal network (KNN) was developed and tested in one-year real operation. In order to achieve reliable results on the economic efficiency or the energy-technical effects of the examined application strategies (e.g. optimisation of self- consumption, shaving of load peaks), these were evaluated both on the basis of real operation and by means of simulation of different scenarios. In the course of the final monitoring phase, a supplementary evaluation of selected environmental impacts was conducted by LCA and desk research and an analysis of the acceptance by the building users was carried out by means of surveys and workshops.

Results, Prospects, Suggestions for future research

• The conducted investigations show that peak loads from PV in commercially used buildings can be reduced by using battery storage systems if a well performing forecasting system with continuous error correction is implemented, especially during high peak load phases. The results show, that both of the used forecast models are only conditionally suitable for forecasting peak loads. Although an artificial neuronal network can optimize the mapping of load profiles, prognosis errors lead to single, not detected load peaks. To reduce these errors a continuous monitoring of the actual energy consumption, in combination with a continuous/permanent error correction, could be integrated.
• The economic assessment shows that the advantages of a storage system are limited. While the increase of PV capacity leads to a decrease of gross costs, the use of a battery storage for PV self-consumption optimization has the opposite effect (+2.77% to +5.77%). However, if a storage unit is also used to reduce peak loads, the economic efficiency can be improved. The total costs are still higher than those without storage, but only by 0.48 % to 1.34 %. It would only need a small reduction of investment costs to make this application economically feasible.
• The life cycle analysis shows that under suitable conditions battery storage systems can improve the climate balance of a building. Depending on the objective of use (peak loads, self consumption, environmental protection), the decisive factors are the choice of technology, the storage strategy (e.g. taking into account the CO2 signal of the electricity mix) or the use of the increased hosting capacity of the respective grid section. Considering and weighing up other factors such as toxicity and availability of raw materials, technologies with higher climate potential can also be used in an environmentally friendly manner.
• In the context of the survey on building users the acceptance of battery storage systems in the context of the workplace was assessed. It was shown that the risk perception regarding battery storages is relatively low and that participants have a generally positive attitude towards the use of batteries in the workplace.

Project management

Kurt Leonhartsberger, MSc., Technikum Wien GmbH

Project or cooperation partners

• TU Wien

• ATB Becker e.U.

• Blue.Sky Energy GmbH

• University of Applied Sciences Technikum Wien

Technikum Wien GmbH
Höchstädtplatz 6
A-1200 Wien
Tel.: +43 (664) 619 25 86
E-mail: kurt.leonhartsberger@technikum-wien.at
Web: http://www.technikum-wien.at/en/