Project name: Connected Stationary Battery Energy Storage

Project name (Croatian): Umreženi stacionarni baterijski spremnici energije – USBSE

Source of funding: European Regional Development Fund, Operational Programme: Competitiveness and Cohesion 2014. - 2020.

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Start date: 13.03.2020.

End date: 07.05.2023.

Project partners:

·       University of Zagreb, Faculty of Electrical Engineering and Computing (lead);

·       Josip Juraj Strossmayer University of Osijek, Faculty of Electrical Engineering, Computer Science and Information Technology Osijek

·       University of Zagreb, Faculty of Economics and Business

·       Total budget: 5.481.718,37 HRK


Project co-ordinator: Prof Hrvoje Pandžić PhD, FER Zagreb

FERIT’s Project co-ordinator: Prof Danijel Topić PhD

FERIT team: Prof Denis Pelin PhD, Prof Goran Knežević PhD, Andrej Brandis MEng, Dragan Vulin PhD, Josip Bilandžić MEng, Zvonimir Šimić MEng

Project summary:

European Commission, with the new energy package called Clean energy for all European package, tends to change the electricity market model while changing the position of the distribution system and its users. New terms and market participants are defined, like distributed flexibility sources and aggregators. Distributed flexibility sources are all users of the distribution grid that can change the power delivered/received to/from the grid according to market/grid signals.

Since distribution grid users have lower installed capacity compared to large market players (power plants connected to transmission grid, traders, and suppliers of electrical energy) their electricity market presence is provided through new wholesale participants called Aggregators of distributed flexibility sources. The project's purpose is to reduce electricity costs to users in buildings and allow active participation in the system operation thereby increasing system safety.  

The above will be achieved through the development of a connected stationary battery energy storage system. The product has three main keys:

  • reduces peak consumption of grid user;
  • shifts consumption from higher (day) to cheaper (night) tariff; 
  • allows participation in providing reserve to grid operators. 

The subject product is of great importance for modern power systems because it allows integration of the greater share of renewable energy sources. Namely, in a conventional power system, consumers were passive and the task of controllable conventional generators (gas, nuclear, thermal, and hydro) was following the load consumption in the power system.

With an increase in the share of renewable energy sources, there are more non-controllable and poorly controllable generators (photovoltaic, wind generators) and system balancing is shifted to consumption that becomes an active participant in the power system.   

Active consumers that have the ability of consumption time shift, that coincides with production from renewable energy sources, are key to a very high share of production from renewable energy sources, consequently sustainable development of modern society. With the system balancing, active consumers with battery storages reduce electricity costs. Namely, commercial consumers, that are consumers whose connected power is above 20 kW, pay engaged power, that is the peak power achieved during the month. With the use of the battery storage that discharges during peak power, consumers reduce fees for engaged power. 

Except for the peak power reduction, with proper management, part of electricity consumption can be shifted from the higher (day) tariff to the lower (night) tariff, which is achieved with charging of battery storage during the night and discharging during the day. While peak power reduction and load shifting reduce electricity costs, providing reserve brings revenue to active consumers. Namely, transmission system operators are obligated to procure reserve services according to the market principles. 

Considering that the power of only one active consumer in most cases is not enough for providing reserve, an aggregator is a new entity on the electricity market that will aggregate a higher number of active grid users, optimize their resources and offer them together on the ancillary service market. Therefore, the important part of this project is the development of the grid aggregator system that will centrally communicate with active grid users that can time-shift their consumption and with transmission system operators to provide the ancillary service – reserve. 

Subject software solution that allows simple connection of the high number of active consumers with battery energy storages is the main advantage of the proposed product in relation to existing battery energy storages available on market.

Main project goals:

  • Development of two battery energy storage prototypes as modular products connected to aggregator software applications.
  • Increase of market-oriented research activities and generation of new values through scientific organizations cooperation.
  • Dissemination of knowledge and products in the business sector through cooperation with existing technology companies and the establishment of a new company.

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