02. CO2 - Tank
For microbiological methanation in the reservoir, CO2 is added to the process. CO2 is supplied in liquid form and stored in a buffer tank on site and can be added as needed. The CO2 comes from a biogenic source.
03. Compressor station
To bring the gas mixture methane / hydrogen / CO2 to the required pressure in order to to be able to bring it into the reservoir, a compressor is needed. Here is a so-called piston compressor machine used. A maximum accumulator pressure of 60 bar is planned.
04. Injection well
The injection and withdrawal in batch operation take place via a well, which is equipped with appropriate safety features. In later cycle operation, this well is only used for storage.
05. Gas reservoir
Millions of years ago, natural gas reservoirs were created in the pores of the sandstone, which are sealed by more than 100 m thick clay layers. Here, large quantities of energy can be stored sustainably, safely and invisibly.
In the Underground Sun Conversion project, the microbiological generation of renewable natural gas will be restarted, a process that took place exactly here millions of years ago.
06. Withdrawal well
The removal of renewable natural gas takes place from the cycle operation via its own well, which is also equipped with appropriate safety features.
07. Drying unit
In a subsurface reservoir gas is absorbing moisture. Therefore, before the gas is discharged into the downstream systems and the pipeline network, a drying is required.
08. Gas conditioning
The gas taken from the reservoir may still contain residual unreacted hydrogen and carbon dioxide. In the course of the project, a membrane separation process is therefore being tested in order to reduce these gas components to a specification-compliant level.
09. Electricity grid connection
The Underground Sun Conversion Project is about storing renewable electricity by converting it into a storable energy source. The renewable electricity is supplied via the power grid and transformed via a transformer to the required voltage levels.
10. Control unit / EMSR
At this point all information comes together, measurement data is processed and forwarded for evaluation. The system operates autonomously during normal operation and is monitored by the headquarters in Gampern. In the event of any fault messages, the on-call service reacts.
Working gas volume
1.7 mn cu m
6.2 mn cu m
100 cu m H2/h