Pilot systems

Starting November 2016, Elestor has successfully carried out out a number of pilots in the field, working under real conditions and connected to renewable energy sources and the grid. The purpose of these pilots was twofold:

1) To demonstrate fundamental proper working

Due to the high scalability of the technology, proper fundamental functioning could already be demonstrated on a limited scale. A large system is in fact only ‘more of the same’, but fundamentally not different from a small system: More membrane stacks deliver more power and larger volumes of active materials deliver more capacity.

This gave Elestor the advantage to start field tests on a limited scale, while the results are representative for large systems.

2) To obtain formal approval from the authorities

Already in an early stage the importance was recognized of learning under what conditions Elestor’s HBr storage can be installed in the built environment. Therefore, a second important goal of these pilots was to have these lessons learned, prior to starting the design of larger systems.

Scaling up to 50 kW and multiples thereof

Since early 2018, the first large storage systems are designed, starting at a power of 8 kW, in combination with a large capacity, like 100 or 250 kWh. Such applications, whereby a limited power is combined with a (very) large capacity, can from an economic point of view only be realized with flow battery technology.

The goals of this scaling phase is to design a 50 kW membrane stack, which then forms the standard power module for all Elestor’s storage systems. A 500 kW system, for instance, then consist of 10 each 50 kW modules.

This modular approach has 3 important advantages:

  • Virtually every desired combination of Power [kW] and Capacity [kWh] can be built
  • Elestor only produces 1 power module (50 kW), thereby taking maximum advantage of economy of scale. This further reduces the Levelised Cost of Storage.
  • The user has the benefit of redundancy.

Presently, 5 large-scale systems have been confirmed:

  • Municipality of Emmeloord, the Netherlands
  • PV park Gansenwoirt, Duiven, the Netherlands
  • 2 systems in Germany
  • ITMGroup, Kampen, the Netherlands

Active projects

FleXtore II

The goal of this project is to arrange the basis for a scalable energy storage system based on the Hydrogen Bromine Flow Battery principles together with belonging external control and an energy management system on a pilot location. The concept shall enable more sustainable energy systems in the build environment (houses or neighbourhoods).

Project partners: • Witteveen+Bos • TNO • HAN • Stichting Pioniers van de Toekomst • ZON Energie • Gemeentewerf Emmeloord

This project receives funding from the Netherlands Enterprise Agency RVO under the TKI Urban Energy program with grant number TEUE116904


The goal of this project is to develop, test and validate a decentralised storage system that consists of a hybrid arrangement between the Hydrogen Bromine Flow Battery and another type of energy storage (here decided for a second life Li-Ion). The belonging energy management system shall optimise the hybrid cooperation between the two storage systems. The HBr battery targets 50kW/250kWh.

Project Partners: • Trinergie • HAN • (Energy Production Company) •

This project receives funding from EFRO/OP-Oost under grant number PROJ-000689

Cleantech Energy Crossing (CEC)

The CEC project consists of several work-packages and Elestor is active in work package (WP) 3, micro-grid storage (other work packages are ‘sustainable heating & cooling’ and ‘batteries at homes’). Within WP3 Elestor will provide a Hydrogen Bromine Flow Battery to work together with decentral energy sources, smart energy management systems and a charging infrastructure for electromobility. The project will include guarantee of energy origin. Within this environment the battery will be tested and validated.

Project partners within WP3: • KiEMT • GWI Essen • (EMS company) • Dr. Ten • GPX Octrooi • Saxion Hogeschool • Zuyd Hogeschool • (Energy Management Company) •

This project receives funding from the INTERREG-program Deutschland-Nederland with grant number 153098 and with support from the European Union, het Nederlandse ministerie van Economische Zaken en Klimaat, provincie Gelderland, provincie Noord-Brabant, provincie Limburg en het “Ministerium für Wirtschaft, Innovation, Digitalisierung und Energie van Nordrhein-Westfalen”


GIFT is an innovative project that aims to decarbonise the energy mix of European islands. European islands have to abide by the law of their countries that push toward a greener energy mix to comply with the European and international agreements. GIFT targets to develop innovative systems to allow islands to integrate vast amount of renewables (e.g. virtual power system, energy management systems, better prediction of supply and demand, visualisation of those data through a GIS platform). Within this context Elestor will provide a Hydrogen Bromine Flow Battery as to be tested in Hinnøya, Norway.

Project partners: • INEA • Euroquality • Harstad • C.R.E.S. • Intracom Telecom • R&D Nester • Sapienza university • Odit-e • Trialog • Hålogaland Kraft AS • Etrel • Comune di Procida • NTNU • ARMINES  • Hafenstrom • Sylfen •

This project receives funding from the European Union’s Horizon 2020 Research and Innovation Program under grant number 824410


FlowCamp is a research and training project from 8 different countries, who will recruit 15 PhD students for the project. The project aims to improve materials for high-performance, low-cost next-generation redox-flow batteries. Renewable energy sources like wind turbines require large-scale, stationary energy storage systems to balance out fluctuations in energy generation. Redox-flow batteries are considered to be one of the most promising solutions. The recruited fellows will develop materials (membranes, electrodes, electrolytes, catalysts, sealing materials) and macrohomogeneous models for three next generation RFBs (hydrogen-bromine, organic and zinc-air systems). They will then upscale the new systems to prototype level, and validate them using the cutting-edge battery testing facilities available for the prestigious German-funded RedoxWind project at Fraunhofer ICT.

Project partners: • Amer-Sil SA • Bar Ilan University • CNRS-LEPMI • CNRS-LRP • MTA-TTK • JenaBatteries GmbH • Johnson Matthey • University of Chemistry and Technology Prague • University of Stuttgart Institute of Machine Components (IMA) • Zurich University of Applied Sciences (ZHAW), Institute of Computational Physics (ICP) •

This project receives funding from the EU Research Executive Agency Marie Sklodowska-Curie Innovative Training Networks under grant number 765289

Elestor’s systems are 100% self-contained. Nothing goes in our out… except electricity!