Introduction

The integration of renewable energy sources, such as solar and wind power, into the electricity grid has become increasingly important in recent years. As the investment costs of solar and wind installations decrease, the main challenge lies in balancing the weather-dependent production of renewable electricity with general power consumption. To address this issue, the BALANCE project, coordinated by VTT Technical Research Centre of Finland, aims to develop a technology called Reversible Solid Oxide Cell (ReSOC). This electrochemical conversion technology enables flexible storage of large amounts of renewable power, promoting the further integration of solar and wind power.

The Imbalance Between Production and Consumption

One of the major obstacles in the integration of renewable electricity into the grid is the imbalance between production and consumption. On windy or sunny days, the electricity market can be flooded with green electricity, causing prices to plunge or even go negative in some European countries. However, since electricity cannot be stored as is, curtailment of wind and solar production becomes necessary to avoid power grid failure. This issue becomes more significant as the production capacity of renewable electricity continues to grow rapidly.

The Role of Reversible Solid Oxide Cells

Reversible Solid Oxide Cells (ReSOC) offer a solution to the challenge of balancing the power market. These devices use electricity to split water into hydrogen and oxygen gas through a high-temperature electrolysis process. ReSOC is significantly more efficient than other electrolyser technologies available today. What sets ReSOC apart is its ability to operate “in reverse.” The same device that produces hydrogen gas through electrolysis can also convert that gas back into power. This flexibility enables the device to have increased operating hours and reduced capital costs.

The Benefits of ReSOC Technology

The integration of ReSOC technology into the power system provides several benefits. During peak production hours, excess power can be converted into a storable chemical, such as hydrogen gas. This chemical can be stored for later use or used as industrial feedstock. On days with low renewable energy production or high consumption, the stored chemical can be converted back into electricity at the same site. This flexible energy conversion technology allows for a more balanced power market and supports the integration of solar and wind power into the current power system. ReSOC units offer a compact, affordable, and flexible solution for the conversion and storage of renewable power.

The BALANCE Project

The BALANCE project, coordinated by VTT Technical Research Centre of Finland, brings together leading European research institutes and universities in the field of electrochemical conversion. The project aims to demonstrate the capabilities of ReSOC technology and its potential for large-scale integration of solar and wind power. The European Commission has provided 2.5 million euros in funding for the project through the Horizon 2020 program. The project, which began in December 2016, will run for three years.

Project Partners

The BALANCE project includes several prominent research institutes and universities across Europe. These institutions collaborate to further develop and refine ReSOC technology. The project partners include:

VTT Technical Research Centre of Finland (FI)
DTU Technical University of Denmark (DK)
CEA French Alternative Energies and Atomic Energy Commission (FR)
ENEA Italian National Agency for New Technologies, Energy and Sustainable Economic Development (IT)
University of Birmingham (UK)
TU Delft Delft University of Technology (NL)
EPFL Ecole Polytechnique Fédérale de Lausanne (CH)
IEn Institute of Power Engineering (PL)

Conclusion

The integration of renewable energy sources, such as solar and wind power, into the electricity grid is crucial for a sustainable future. However, the imbalance between production and consumption poses a significant challenge. The BALANCE project aims to address this challenge by developing Reversible Solid Oxide Cell (ReSOC) technology. ReSOC enables flexible storage of large amounts of renewable power, allowing for better integration of solar and wind power into the current power system. With the support of the European Commission and collaboration among leading research institutes, the BALANCE project is paving the way for a more sustainable and efficient energy future.

Figure: Schematics of the ReSOC concept. It is the missing link between the power grid and the fuel or the chemical feedstock for the industry.