Deutsche Erdwärme Launches Long-Term Geothermal Productivity Test in Graben-Neudorf

Deutsche Erdwärme Starts Long-Term Geothermal Test in Graben-Neudorf

After months of inactivity, the geothermal project in Graben-Neudorf (Karlsruhe district) is springing back to life. Deutsche Erdwärme has initiated a long-term test to evaluate the productivity of its 3,600-meter-deep borehole. The test, expected to run for two to three weeks, is seen as a critical step in determining the feasibility of large-scale geothermal energy production at the site.

The central question: Is the geothermal well as productive as Deutsche Erdwärme anticipates? According to reports by SWR, water will be pumped into the underground reservoir, followed by seismological measurements and pressure tests. These activities aim to determine the operational conditions required for safely running a future geothermal plant.

Herbert Pohl, CEO of Deutsche Erdwärme, noted that such a long-term test is unprecedented in Germany and in the Upper Rhine Valley. While geothermal exploration in Graben-Neudorf has been ongoing for decades, this advanced stage of the project focuses on securing sustainable heat extraction and simulating plant operations. Systematic geothermal studies at the site date back more than 30 years.

During the test, significant amounts of water will be injected into the hot underground reservoir. Pressure will be applied carefully to avoid triggering significant seismic events, preventing incidents similar to those experienced in Basel or Landau.

A key goal of this long-term test is to ensure a reliable supply of heat for a regional district heating network. At a minimum, the communities of Graben-Neudorf and the city of Bruchsal are expected to benefit. Deutsche Erdwärme is also in discussions with additional municipal utilities. Further drilling is planned nearby in Dettenheim, although regulatory conditions are still being finalized.

If everything goes according to plan, a second borehole will follow next year in Graben-Neudorf—essential for the eventual operation of the geothermal plant. However, exact dates are not yet confirmed. Only a few specialized drilling rigs in Europe are capable of reaching these depths, so work will resume once equipment becomes available.

With temperatures exceeding 200°C at around 3,600 meters deep, Graben-Neudorf is considered Germany’s hottest thermal water source. Extracting this extremely hot water requires specialized heat-resistant technology, which was not part of the original design. Deutsche Erdwärme aims to begin routine extraction of hot thermal water by 2029. Meanwhile, a geothermal power plant will be constructed on-site to process the heat efficiently.

Deutsche Erdwärme’s long-term test marks a significant milestone in Germany’s geothermal energy sector. Success in Graben-Neudorf could not only provide clean, sustainable heat to local communities but also set a benchmark for geothermal projects across the Upper Rhine Valley.

Source: SWR

Connect with us: LinkedIn, X

Comments

Hot Topics

Blowout at Cape Station: Fervo Energy’s First Major Crisis After Blockbuster IPO

Just weeks after a record-breaking IPO, the flagship project of the "geothermal unicorn" faces its first major operational crisis. By : Robert Buluma Beaver County, Utah – The morning of May 27, 2026, began like any other at the Cape Station construction site in rural Utah. Workers for Fervo Energy, the newly public darling of the renewable energy world, were engaged in the complex task of drilling deep into the Earth’s crust to unlock what the company promised would be the future of 24/7 clean power. But by the afternoon, the routine had turned into a crisis. The site had experienced a blowout—an uncontrolled release of fluid or pressure from a well. For any energy company, a blowout is a serious matter. For Fervo Energy, which had just raised $1.89 billion in a blockbuster Nasdaq debut two weeks prior, it represents an immediate stress test of its technology, its safety protocols, and its $7.7 billion market valuation. While the well has since been contained and no injur...

Eavor steps back from operator role in the Geretsried geothermal project

Eavor at the Crossroads: What Geretsried Really Tells Us About the Future of Closed-Loop Geothermal By Alphaxioms Geothermal Insights | May 13, 2026 For years, Eavor Technologies was the geothermal sector's most talked-about enigma. The company raised hundreds of millions of dollars, attracted backing from heavyweights including BP , Chevron , Helmerich & Payne , and Temasek , and made bold promises about a proprietary closed-loop technology that would quietly revolutionise how humanity extracts heat from the earth. But it rarely said much in public. The secrecy was, to many observers in the geothermal community, a feature rather than a bug — protecting intellectual property, managing competitive intelligence, buying time. Now, Eavor is talking. And what it is saying is worth listening to very carefully. In an exclusive interview published on May 13, 2026, by GeoExpro editor Henk Kombrink, Eavor's new president and CEO Mark Fitzgerald — who took the role in October 2025 ...

Eavor Geretsried Geothermal Breakthrough: Inside the Closed-Loop Energy Revolution, Drilling Challenges, and Path to Scalable Clean Power

The Geothermal “Holy Grail” Just Got a Reality Check: Inside Eavor’s Geretsried Breakthrough By: Robert Buluma May 22, 2026 It’s not every day a deep-tech energy company publishes a detailed technical report that openly documents what went wrong on its flagship project—and still comes out looking stronger. That’s exactly what Eavor Technologies did with its Geretsried geothermal project in Bavaria, Germany. The result is unusually transparent: part technical post-mortem, part validation of a technology many have doubted for years. And the core message is simple. They built it. It works. But it wasn’t smooth. The short version Eavor is trying to solve one of geothermal energy’s hardest problems: how to produce reliable heat and power anywhere, not just in rare volcanic hotspots. Their claim has always been bold: a closed-loop geothermal system that is scalable, dispatchable, low-carbon, and independent of natural reservoirs. Critics have long argued it wouldn’t survive...

GEN Electric Grid Impact Study RFP in Framingham Massachusetts Advances Utility Geothermal Networks

GEN Electric Grid Impact Study RFP Signals a Defining Moment for Geothermal Energy Networks in the United States By: Robert Buluma The United States geothermal sector is entering a new phase, one where geothermal systems are no longer being viewed only as sources of heating and cooling, but increasingly as strategic infrastructure capable of strengthening the electric grid itself. In one of the most important emerging developments in utility-scale thermal network deployment, the Home Energy Efficiency Team (HEET), in partnership with Eversource Gas, has officially launched a Request for Proposals (RFP) for a groundbreaking Electric Grid Impact Study focused on Geothermal Energy Networks (GENs), also referred to as Thermal Energy Networks (TENs). Backed by funding from the U.S. Department of Energy under grant “DE-EE0010662.0002 Home Energy Efficiency Team Utility-Managed Geothermal Pilot in Framingham, Massachusetts,” the initiative represents far more than a local energy pilot. It is...

Rodatherm Energy: The Refrigerant Gambit

By: Robert Buluma Rodatherm Energy has done something no other geothermal startup has attempted at commercial scale: swapped water for refrigerant in a closed-loop system. The claim is 50% higher thermal efficiency than water-based binary cycles, achieved by circulating a proprietary phase-change fluid through a fully cased, pressurized wellbore. The company emerged from stealth in September 2025 with a $38 million Series A—the largest first venture raise in geothermal history. Lead investor Evok Innovations was joined by Toyota Ventures, TDK Ventures, and the Grantham Foundation. The engineering thesis is elegant. The execution risks are significant. This is an Alphaxioms examination of both. II. The Thermodynamic Distinction Every geothermal company you've covered moves heat using water or steam. Rodatherm moves heat using a fluid that boils and condenses inside the wellbore. In a conventional closed-loop water system (Eavor's model), water circulates as a single-phase liq...

LCOE Benchmarking: Eavor Technologies vs. Fervo Energy

LCOE Compared: Eavor Technologies vs. Fervo Energy Two Bets on Next-Generation Geothermal An Alphaxioms Geothermal Insights Analysis | May 2026 Image: Eavor and Fervo Drilling Rigs well poised in their respective well pads , drill baby , baby what a time to be a live Introduction: Why the Cost Question Matters Now The global geothermal sector is in the middle of a pivotal moment. After decades of stagnation largely confined to volcanic hotspots, two fundamentally different technological approaches are racing to prove that geothermal energy can be deployed broadly, cheaply, and at scale. Eavor Technologies , the Calgary-based advanced geothermal systems (AGS) company, and Fervo Energy , the Houston-based enhanced geothermal systems (EGS) pioneer, represent the sharpest divergence in next-generation geothermal strategy today. Each company is backed by hundreds of millions of dollars in private capital, each has reached key commercial milestones, and each is advancing ...

Germany’s Hidden Heat Rush: Inside the Massive Urban Geothermal Hunt Beneath Erfurt’s Streets

Germany’s Urban Geothermal Gamble: Inside the Massive 3D Seismic Campaign Beneath Erfurt’s Streets by Geofizyka Torun By : Robert Buluma In the heart of Germany, something extraordinary is happening beneath the sidewalks, apartment blocks, cafés, and busy streets of Erfurt. While most residents move through their daily routines unaware, fleets of heavy vibrotrucks and thousands of seismic receivers have been quietly scanning the Earth below the city in one of Europe’s most ambitious urban geothermal exploration campaigns. The recent completion of a demanding 3D seismic survey campaign by Geofizyka Torun S.A. marks far more than a technical milestone. It represents a glimpse into the future of European energy — a future where cities no longer rely heavily on imported fossil fuels, but instead tap into the immense heat hidden beneath their own foundations. Germany’s geothermal race is accelerating, and Erfurt has suddenly become one of the most fascinating battlegrounds in Europe’...

The XGS Energy Heat Sponge Solves Geothermal's Biggest Problem

The XGS Energy Heat Sponge Solves Geothermal's Biggest Problem I mage: A californian XGS well pad Imagine drilling a hole into the Earth’s hot crust but instead of simply dropping in a pipe and hoping for the best, you paint the inside of that hole with a magic material that soaks up heat like a sponge soaks up water. Then you seal it, circulate a fluid, and generate clean, firm electricity 24/7, no fracking, no water consumption, no earthquakes. That’s not science fiction. That’s XGS Energy . While most of the geothermal world has been chasing fracked reservoirs or massive drilling rigs, XGS quietly built a prototype, ran it for over 3,000 hours in one of the harshest geothermal environments on Earth, and landed a 150 MW deal with Meta – enough to power tens of thousands of homes or a massive data center campus. This is the story of a technology that might be the most elegant, low-risk, and capital-efficient path to scalable geothermal power. Let’s dig in. Part 1: The Pro...

Iceland Drilling Company Reveals Future of Deep Geothermal Innovation

Exclusive Expert Insights on Superhot Resources, Cost Barriers, Africa’s Growth, and the Next Era of Geothermal Energy By : Robert Buluma Image:Bruce Gatherer, Geothermal Drilling Business Development & Operations Advisor at Iceland Drilling Company, and Sveinn Hannesson, CEO, who provided the expert insights behind this exclusive interview. Geothermal energy is entering a new and far more extreme frontier. As the global energy transition accelerates, attention is shifting from conventional hydrothermal systems to superhot, ultra-deep, and engineered geothermal systems that promise dramatically higher energy yields and broader geographic applicability. In this exclusive expert exchange, Iceland Drilling Company shares detailed insights on the future of geothermal drilling,covering technical frontiers, cost structures, workforce challenges, Africa’s geothermal opportunity, oil and gas crossover, digitalization, partnerships, and what the next 10–15 years may hold f...

MND Completes Landmark Deep Geothermal Drilling Project in Košice, Powering Central Europe’s Clean Heating Future

MND Pushes Central Europe Toward a Geothermal Future with Landmark Košice Project Central Europe has just witnessed a major geothermal breakthrough. Czech energy and drilling giant MND has officially completed the drilling phase of one of the largest geothermal heating projects in Central Europe, marking a decisive moment not only for Slovakia’s energy future, but also for the wider European geothermal sector. Located in the city of Košice, Slovakia’s second-largest city, the ambitious geothermal development demonstrates how deep geothermal energy is rapidly transforming from a niche renewable resource into a strategic pillar of urban energy security, district heating, and industrial decarbonization. The announcement by MND revealed that three deep geothermal boreholes were successfully drilled to depths of up to 3.6 kilometers under difficult geological conditions. Once fully operational, the geothermal system could cover as much as 55% of Košice’s heat consumption — an extraordina...

ALPHAXIOMS Geothermal News & Energy Research

Search This Blog