Germany's EWE Huntorf 16 million cubic meter hydrogen storage project completes wellbore airtightness test

en.Wedoany.com Reported - On November 6, the gas storage subsidiary of German energy company EWE achieved a new technical validation milestone at its underground hydrogen storage project in Huntorf, Lower Saxony, completing the airtightness test of a converted wellbore at an existing natural gas salt cavern. The test was conducted using nitrogen and hydrogen successively, and all measurement results met the specified acceptance criteria. The salt cavern is planned to enter operation in 2028, with a designed hydrogen working gas volume of approximately 16 million standard cubic meters, equivalent to about 1,440 tonnes of hydrogen.

The test subject was the technically modified wellbore of an existing salt cavern and its sealing structure between the wellbore and the surrounding geological formation. EWE installed a new cemented casing within the existing wellbore, completing the wellbore conversion using improved cement materials and additional sealing elements. The test first used nitrogen to verify the system's sealing performance, followed by hydrogen to validate airtightness under actual storage medium conditions. The project team confirmed that all parameters remained within specified ranges during testing, and no abnormal pressure changes occurred in the monitored areas.

The Huntorf gas storage site currently has seven underground natural gas salt caverns, one of which was involved in this conversion. Upon completion of the conversion, the hydrogen storage facility is planned to have a combined hydrogen injection and withdrawal capacity of 35,000 standard cubic meters per hour. The project will repurpose existing underground gas storage facilities, converting the original natural gas storage facility for hydrogen storage through wellbore modification, gas compression, drying treatment, and transmission pipeline connection works.

With the wellbore airtightness verification completed, EWE plans to continue with downhole equipment installation starting in mid-November 2026, including the tubing system for hydrogen injection and withdrawal and additional safety devices. Surface works are proceeding in parallel, including construction of the hydrogen storage facility foundation, underground cable conduits, drainage facilities, and operational buildings, with compression, gas treatment, and associated control equipment to be installed subsequently.

Procurement of supporting equipment for the project has entered the contract execution phase. EWE has commissioned Germany's NEUMAN & ESSER to supply two hydrogen compressors for injection and withdrawal operations at the hydrogen storage facility; Bilfinger is responsible for the engineering design, installation, and commissioning of the hydrogen drying treatment facility. The facility will use Bilfinger's H2Dry technology to dehydrate hydrogen withdrawn from the underground salt cavern to meet subsequent pipeline transmission requirements.

The Huntorf hydrogen storage project will also be connected to Germany's hydrogen core network via the H₂Coastlink 2 pipeline. The supporting pipeline has a total length of approximately 34 kilometers, connecting Huntorf and Sandkrug, of which approximately 28 kilometers utilizes converted existing natural gas pipelines and approximately 6 kilometers consists of newly built pipeline sections. The pipeline is planned to be operational by the end of 2027, and the underground hydrogen storage facility is planned to be connected to the hydrogen core network and enter operation in 2028.

The project is part of EWE's Clean Hydrogen Coastline hydrogen infrastructure program, supported by the German federal government, the Lower Saxony state government, and the Important Projects of Common European Interest (IPCEI) mechanism. The program also encompasses the 320 MW electrolytic hydrogen production facility under construction in the Emden area, with the hydrogen production, pipeline, and underground storage facilities progressing according to their respective construction schedules.