Our facility

Since January 2011 our world-class, fast-cycle gas storage facility is operational. We achieve high injection and withdrawal rates per hour, one of the highest turnover rates in the world and a switch time between injection and withdrawal of under 15 minutes.

Our facility is located in the north of the Netherlands and is connected to the reliable Dutch gas transmission network, in the heart of the TTF-market. Gas is stored in five salt caverns at a depth between 1,000 and 1,500 metres whose gas volume ranges from 5,000 MWh  to 10,000 MWh. The technical lay out consists of two tubings per cavern in stead of one tubing that results in an exceptionally high injection and withdrawal rate. Gas is injected into the caverns using electric compressors and is withdrawn using equipment for heating, pressure reduction and gas drying. 

Injection and withdrawal capacity is available 24/7 throughout the year. The facility has a high reliability with an efficient short period of yearly maintenance that is principally planned during summer.

Main properties

Number of caverns 5
Tubings per cavern 2
Gas quality low caloric Groningen gas
Working gas volume approx. 2,850 GWh
Total withdrawal capacity 18 GWh/h
Total injection capacity 13.2 GWh/h

 


Certified ISO 50001 energy management certificate


We are proud to be the first Dutch energy company that has obtained an ISO 50001 energy management certificate (June 2016).
The ISO 50001 certificate has been awarded to recognize that we have a process in place to continually address and improve the energy usage and the related footprint of our operations.

The ISO 50001 certificate underpins our strategy to improve our energy-efficiency and footprint reduction. This certificate is not an end in itself but represents the start of more initiatives in this area. We aim to continue to reduce our energy use, our energy costs and our greenhouse gas emissions. For instance, in 2016 we started to purchase certificates for electricity that has been generated by sustainable sources. We aim to increase this percentage gradually over the coming years. As well as implementing sustainable energy sources, we will also continue to work on reducing our energy consumption.


All parts off the facility explained

This interactive infographic explains the function of all parts of the installation. Click on a part of the image for a detailed description.


Control room

The facility has a control room where the processes can be monitored and controlled. In general, this only happens during maintenance. Normally, the facility is controlled from the Gasunie Central Command Post. There, the facility and caverns can be monitored and controlled in real time. Otherwise, the facility can be operated completely unmanned.
The customers of EnergyStock determine what is injected or withdrawn. Their requests ultimately  result in gas either being injected or withdrawn from the facility.

Boilers

The pressure in the caverns is between eighty and one hundred and eighty bar. The pressure in the Dutch gas transport network is approximately sixty bar. Therefore the pressure is being reduced. The gas is then warmed up using hot water, which is heated by boilers. This is done because the pressure reduction causes the gas to cool down. After pressure reduction, the temperature should be fifteen degrees Celcius.

Heater/Choke trains

In the heater/choke trains, the gas is first heated up using hot water from the boilers. The pressure is then reduced to 60 bar using chokes, making the gas suitable for the Dutch gas transport network.

Glycol contactors

The last step in the process is the removal of moisture from the gas. The gas coming from the caverns is damp because the walls and the bottom of the caverns are wet due to the leaching process. In the glycol contactor, which is a high upright vessel, the gas comes in intensive contact with glycol, resulting in the gas being dried. The dry gas then flows on and the moisture-saturated glycol is collected. The glycol is then separated from the moisture so that it can be reused. This is done in a glycol regeneration unit.