FAQ & Resources

More information about the Corre Energy project

About Us

Corre Energy is a leader in the development and operation of Long Duration Energy Storage (LDES) projects and products that will accelerate decarbonisation and enhance security and flexibility of energy systems. Our initial market focus is Europe, with anticipated expansion into other major markets.

Corre Energy was founded in 2018 and is headquartered in Groningen, in the Mediacentrale, where there is a fast-growing Dutch team. Corre Energy B.V. was listed on Euronext Growth Dublin in September 2021.

At Corre Energy, we believe that no renewable energy should go to waste. On occasions where wind blows heavily and a lot of energy is produced, there are times when we can't use it all and energy is wasted. Energy storage is the key to prevent this. We are already seeing storage solve this challenge in the form of large batteries, which generate electricity for every hour. Unfortunately, an unprecedented number of these batteries would be required to solve the problem of the world’s surplus electricity.

At Corre Energy, we aim to store energy in salt caverns. We ensure that surplus renewable energy can be preserved and reused at times when there is demand.

The transition to a completely CO2-free electricity network cannot take place without long-term energy storage. Solar and wind energy are clean and available, making them fast-growing forms of energy generation. The challenge, however, is that the sun doesn't always shine, and the wind doesn't always blow. This causes the supply of renewable energy to vary throughout the day.

To solve the problem of energy supply interruptions, the grid needs to couple renewable energy generation with large amounts of energy storage to store excess energy. This will ensure that we can use it at a later date, when the supply of renewable energy cannot meet the demand. Long duration energy storage is essential to enable the energy transition.

Corre Energy B.V. is in Groningen, specifically the Mediacentrale, Helperpark 278-3, 9723 ZA.

About the Project

To achieve a properly functioning and safe, large-scale, underground energy storage with compressed air, there are several steps that must be followed.

The Engineering – the design

It all starts with designing the installation and the salt cavern where compressed air will be stored. Following this, permit applications must be made and the design elaborated down to the smallest detail. When the necessary permits have been granted, the actual construction begins.


The construction can roughly be divided into two parts: the underground salt caverns and the above ground associated installation. The salt caverns (large, solid cavities in the salt layers in the soil) are made by dissolving salt. 

The salt caverns must then be prepared for compressed air storage. Once the salt caverns and the associated above ground installation / buildings are ready, tests will be conducted to ensure that everything is working properly. Only when the relevant licenses have been granted will the entire installation be put into operation.

The intended location is in Zuidwending, between the Provincialeweg N366 and the Zoutweg, next to the Heeresmeer. This is a logical location because storage is already taking place nearby. You cannot just build a compressed air installation anywhere, there are several factors that play a major role in this.

Some of the factors that must be considered include the following:

  1. Firstly, access to a salt formation and looking at the subsoil. Due to its hardness and density, salt is extremely suitable for the storage of air.
  2. A close connection to the national electricity network. In Zuidwending this is the TenneT station in Meeden.
  3. In the immediate vicinity there is a defined need for long duration energy storage from industry and TenneT, the grid operator
  4. The presence of renewable sources is vital. In this environment, there is plenty of renewable energy available from wind and solar parks.
  5. Finally, access to hydrogen. In fact, we are one of the first companies to make an active contribution to the hydrogen economy. That is an important ambition for the province of Groningen.

Little to no activities will take place in the coming year. At present, the intended start date of this project is 2023, and the first work related to a test drilling will be carried out. In the design phase, we study possible noise nuisance as well as the necessary restrictive measures, ensuring that the area is considered as much as possible during installation.

As part of the permitting process, we will work with key stakeholders to ensure noise reduction measures are included in the project design; this also applies to considering the impact of traffic. During the design phase, we will investigate the potential impact of the project on traffic, not only in terms of noise, but the overall effect during the construction and implementation phase. We look at the possibilities of the design to minimise the total impact.

Compressed Air Energy Storage, or CAES, is the storage of compressed air to produce energy. It is also known as Long Duration Energy Storage (LDES). Compressed Air Energy Storage (CAES) can store energy cost-effectively for longer periods of time than batteries, has a longer lifespan, and lower environmental impact with a lower overall carbon footprint.

Excess renewables are converted into compressed air and stored in a cavern. Compressed air can be stored in a cavern for a long time, ensuring that the use of energy from solar parks and wind farms is not restricted to when the sun is shining, and the wind is blowing. This compressed air can then be passed through a turbine to generate electricity when the power grid needs it. The air is used to drive a turbine to make electricity as and when it is needed.

During CAES operations, the pressure in the caverns fluctuates between 90 bar (minimum pressure) and 190 bar (maximum pressure). The caverns can easily handle a higher pressure (approx. 240 bar) due to its depth at 1,100 meters.

Additionally, the compressors cannot deliver more than 190 bar. The cavern can also handle a lower pressure without problems, even atmospheric, but by keeping the cavern at a certain pressure (i.e. 90 bar) we will always remain within permitted pressure ranges.

As mentioned above, the pressure in the CAES cavern remains well below the pressure at which there is a possible risk of damage.

Gas is extracted from a gas field whereas compressed air is stored in a purpose designed salt cavern. These activities are very different from each other and therefore cannot be compared. The pressure in the cavern during CAES fluctuates between 90 and 190 bar. A cavern is located in a deep layer of rock salt, several hundred meters below the surface. This rock salt has a homogeneous structure, meaning that it has a dense and solid structure. Because this structure is so solid, we can say that storing air in these caverns cannot cause earthquakes.

Nevertheless, Corre Energy will participate in the microseismic monitoring network that EnergyStock and Nobian will install around the Zuidwending salt dome. Compressed air storage using caverns involves a gradual change in pressure in a CAES cavern,  you can think of this as a completely closed pressure vessel. Due to the hundreds of meters of thick salt positioned above and next to it, these pressure changes are not noticeable outside of the salt. Since there are no fractures in the salt, due to its structure, it can be stated that compressed air storage in caverns at approximately 1,100 meters, and at a pressure between 90 and 190 bar, cannot cause earthquakes.

Safety is continuously and extensively considered in both the design and the permit applications. Strict guidelines will be met. During all phases of the project, safety is our number one priority.

The storage of compressed air is not new. The existing installations in Huntdorf, Germany and McIntosh, Alabama USA have been running without problems for several decades. Corre Energy is also not the only organisation involved in this. Internationally, there are several organisations that are involved in compressed air storage.

Subject to permiting, the test well phase could begin in 2023. The results of which will be used to ensure that the location is suitable for compressed air storage and will lead into the construction of the two salt caverns. When constructed, the associated above-ground installation (including buildings) can begin.

Compressed Air Energy Storage systems are very durable and future-proof. They form the foundation for a CO2-free electricity network and a renewable future. We use technology that has proven itself in various mechanical processes and is known to have a long service life. This enables CAES to achieve a reliable service life of at least 35 years, with normal equipment maintenance.

Permits and influence on the area

Corre Energy will regularly organise information evenings to inform you about upcoming developments. More importantly, on these evenings we welcome you to provide your thoughts on our plans. We therefore cordially invite you to register for these evenings.

The following permits are being requested for this project:

  • An Environmental Impact Assessment (EIA)
  • Notice Participation
  • Announcement intention
  • Nature permit
  • Water permit
  • Environmental permit
  • Storage permit
  • Integration plan
  • WABO
  • Drilling plan for the test drilling

We do everything we can to carry out everything in close consultation with all parties involved. We can imagine that you have questions about the progress and the packaging of the project. That is why we regularly organise information evenings to keep you informed of these developments.

We prefer to receive questions and reports at [email protected].

Corre Energy will regularly organise information evenings to inform you about upcoming developments. More importantly, on these evenings we welcome you to provide your thoughts on our plans. We therefore cordially invite you to register for these evenings.

We prefer to receive questions, comments and suggestions for improvement at [email protected].

Marjolein Overbosch, Head of Communications at Corre Energy for the CAES ZW1 project, is your primary point of contact.

Marjolein can be reached in the following ways:

While we aim to limit inconvenience as much as possible, should you experience nuisance because of the activities of Corre Energy and the Zuidwending project then please let us know.

We can be reached via the Contact us page, the e-mail address [email protected], or the telephone number 050 – 799 5056.

We take all possible measures to prevent damage and/or nuisance. Do you suspect that you have suffered damage in relation to this project? Then you can contact the Mining Damage Committee. They can also be reached from Monday to Friday between 08:30 and 17:00 on telephone number 088 – 042 42 70.

No, the activities in and around the caverns do not cause earthquakes. The soil is constantly in motion and micro-vibrations take place. These vibrations can occur through natural processes or underground activities. CAES takes place underground, 800 meters below the surface.

If you suspect that there has been an earthquake in relation to this project, please report it to the Mining Damage Committee. They can also be reached from Monday to Friday between 08:30 and 17:00 on telephone number 088 – 042 42 70.

Because compressed air storage does not cause earthquakes, there will be no sudden damage. In addition, the subsidence that occurs during CAES is nil and, if it does occur, it occurs in a vast area (up to about 1 to 1.5 km from the cavern). To keep a close eye on subsidence, Corre Energy will participate in the subsidence monitoring network that EnergyStock and Nobian already maintain around the Zuidwending dome (and this will be expanded where necessary because of the CAES caverns).

We can explain to you what our plans are, why we know those plans are safe, and we are honest about what you will or won't notice. Corre Energy cannot dispel the fear that has arisen in recent decades, for example as a result of the earthquakes caused by gas extraction.

We are open to discussion and take your concerns very seriously. Please, feel free to let us know if you have any questions or concerns. For this you can reach us at [email protected] or by telephone on 050-7995056.

We are also open to changes to our plans if they relate to the reduction of nuisance, lead to less light pollution or benefit the environment. For example, you can think of green areas, planting trees or other ideas that benefit the integration into the environment.

The transition to a completely CO2-free electricity network cannot take place without long-term energy storage. Solar and wind energy are clean and available, making them fast-growing forms of energy generation. The more solar panels and wind turbines there are, the more often there will be surplus renewable electricity that can be used to store compressed air. To balance this, the long-term storage of large amounts of energy is important. This is something that currently does not exist; CAES can fulfill that role.

CAES ensures that when it is dark and the wind is not blowing, electricity can still be produced in a renewable way. With a capacity of no less than 320 MW, we can provide a renewable electricity equivalent for the consumption of 158,000 homes.