Reversible SOC System

A reversible SOC system is a type of energy management system that uses a single SOC to switch between "SOEC, which produces hydrogen through water electrolysis," and "SOFC, which generates electricity through fuel cell action." By operating in conjunction with renewable energy generation, surplus electricity can be stored in the form of hydrogen when it is generated, and can then be used to generate electricity as needed through hydrogen power generation.

• Hydrogen production using solid oxide electrolysis cells (SOEC)

  Utilizing the technology cultivated in oxygen sensors*, hydrogen can be produced from electricity and water using ceramic SOEC. This enables highly efficient hydrogen production by combining waste heat from methanation and other sources.

  *For more information on oxygen sensors, click here

• Hydrogen generation by SOFC (Solid Oxide Fuel Cell)

  SOFC (Solid Oxide Fuel Cell)* is a device that produces electricity from hydrogen and other fuels.
  When water is electrolyzed, hydrogen and oxygen are produced.

• Hydrogen power generation using SOFC (Solid Oxide Fuel Cells)

  SOFC (Solid Oxide Fuel Cell)* is a device that generates electricity from fuels such as hydrogen.
  When water is electrolyzed, hydrogen and oxygen are produced, but the opposite can also be done by reacting hydrogen and oxygen to produce electricity.

  *For more information on SOFC, click here

The system enables two types of operation: "SOEC," which electrolyzes water to produce hydrogen by passing electricity through it, and "SOFC," which produces electricity by reacting hydrogen with hydrogen. Both technologies do not emit greenhouse gases such as CO₂, making them essential for achieving carbon neutrality.
Since a single stack can be used to switch between hydrogen production and power generation, the system can be made more compact than a combination of SOEC and SOFC, which has the advantage of requiring a smaller installation area.
In an SOC system, the cell stack needs to be kept at a high temperature of around 700°C, and the management of this thermal energy has a major impact on the efficiency of the system. The system is equipped with a compact, highly efficient hot module*1 that can effectively utilize the heat generated inside the system, and utilizes our long-cultivated technologies for controlling electrochemical properties of cell stacks in high-temperature environments and for thermal fluid analysis.

*1: A hot module is a structure consisting of a cell stack, heat source, gas piping, and insulation. It is highly efficient in raising the temperature of the cell stack to around 700°C and maintaining that high temperature.

By combining solar power generation, which experiences large seasonal fluctuations in power generation, with a hydrogen storage system, surplus electricity in the summer can be converted into and stored as hydrogen in the SOEC, and electricity shortages in the winter can be made up for by SOFC generation using the hydrogen stored in the summer, making it possible to adjust electricity supply and demand between seasons.
In addition, when a power outage occurs due to a disaster, solar power generation can be used during the day, but power cannot be obtained during bad weather or at night. The SOC system can generate electricity at any time using stored hydrogen, providing a flexible energy supply at any time of the day and night, and can also serve as an emergency power source.

In addition to improving the SOC system and obtaining operational results, we will also conduct educational activities to promote the spread of SOC systems in society and search for collaborative partners with the aim of commercializing the system in the future.
In the SOC business, we aim to be a leading company in the industry that can provide a wide range of customers with cell stacks, hot modules, and systems, and to contribute to the creation of a sustainable society.