Green Therma and GFZ Potsdam Launch Breakthrough Geothermal Demonstration

Turning Deep Earth Heat Into a Scalable Climate Solution: Green Therma and GFZ Potsdam Launch Breakthrough Geothermal Demonstration

By:Robert Buluma

Published on January 17, 2026

In the quest for reliable, carbon-neutral energy, geothermal heat stands out as one of the most promising yet underutilized resources. Unlike solar or wind, which depend on weather, geothermal energy draws from the Earth's constant internal heat — a source that's available 24/7, year-round. However, traditional geothermal systems often face high costs, geological risks, and significant heat loss when extracting energy from great depths.

Enter Green Therma, a Danish innovator, and the Helmholtz Centre Potsdam GFZ (Germany's leading earth sciences research center). In early 2026, they're launching a groundbreaking demonstration at the renowned geothermal research site in Groß Schönebeck, north of Berlin. This project marks the world's first real-world installation of Green Therma's patented DualVac™ vacuumized pipe technology in a deep geothermal well — a potential game-changer for making deep geothermal scalable and efficient worldwide.

The Challenge of Deep Geothermal Heat

Deep beneath the surface — typically 3 kilometers or more — rock temperatures exceed 100°C, offering immense potential for heating homes, industries, and entire cities. But bringing that heat to the surface without losing most of it has been a major hurdle. Conventional systems often require two wells (one for injection, one for production), depend on permeable rock formations, and suffer from thermal losses during fluid transport.

Green Therma's Heat4Ever™ solution addresses these issues head-on. It's a closed-loop system using a single well, where water circulates in sealed pipes to absorb heat from the surrounding hot rock without ever mixing with underground fluids. This eliminates geological risks like poor permeability or scaling, reduces environmental impact, and allows deployment in almost any location.

At the heart of the system is the innovative DualVac technology — a coaxial pipe design that creates a continuous vacuum along the entire pipe string, acting like an advanced thermos. Hot fluid rises in an insulated inner pipe while cold fluid descends in the outer one, with the vacuum minimizing heat loss dramatically. This enables efficient heat delivery from depths of 3+ km, where temperatures are high enough for direct use in district heating or industrial processes (no extra heat pumps needed in many cases).

The Groß Schönebeck Demonstration: A Milestone Moment

The Groß Schönebeck site, operated by GFZ Potsdam for over two decades, is an ideal testing ground. The location features wells reaching depths of 3.9–4.4 km with temperatures around 150°C, making it perfect for validating advanced technologies.

In this collaboration — part of the European TRANSGEO initiative (focused on repurposing existing wells for geothermal heat extraction and storage) — Green Therma will install the **DualVac™ completion in a co-axial single-well system at approximately 3.2 km depth. Full operations are expected in the first half of 2026, with a year-long testing phase to monitor performance under real conditions.

Key project details at a glance:

Project Name: Heat4Ever™ Test Project

Technology: DualVac™ vacuumized pipe completion in a co-axial geothermal system

Depth: ~3.2 km (temperatures >100°C)

Location: Groß Schönebeck, Germany

Timeline: Full operation in first half of 2026; one-year test period

Partners: GFZ Helmholtz Centre for Geosciences and Green Therma ApS

Quotes from the leaders capture the excitement:

“This project represents a milestone in geothermal energy extraction technology,” says Jørgen Peter Rasmussen, Founder and CEO of Green Therma. “By demonstrating DualVac™ insulation performance at Groß Schönebeck, we are taking a major step toward making deep geothermal heat accessible, efficient, and scalable on a global level.”

Prof. Dr. Ingo Sass, Head of the Geoenergy Section at GFZ Potsdam, emphasizes the value of collaboration: “Close cooperation between industry and research is essential for developing next-generation geothermal solutions.”

Prof. Dr. Hannes Hofmann, TRANSGEO Coordinator, adds: “Groß Schönebeck is one of the places where Europe tests what tomorrow’s geothermal systems could look like. The knowledge generated here could help expand geothermal energy in regions that need scalable, clean heat.”

Why This Matters for the Climate and Energy Future

Heating accounts for a large share of global energy use and emissions, especially in Europe where winter demand is high. Many areas lack abundant wind or solar resources during cold months, and switching entire heating infrastructures takes time.

Deep geothermal offers a stable, weather-independent alternative: baseload renewable heat that's local, secure, and fossil-free. If DualVac™ proves its efficiency — drastically reducing heat loss and enabling single-well designs — it could lower project costs, speed deployment, and open up new regions (including urban and industrial areas) previously deemed unsuitable.

Green Therma has already built momentum with prior milestones, including a successful DualVac™ functionality test in 2024 at Norway's Ullrigg facility (part of the Horizon Europe HOCLOOP project) and a major full-scale demonstration planned in Aalborg, Denmark, backed by significant funding and a 30-year heat purchase agreement with local utilities.

This German demonstration builds on that foundation, providing critical field data to refine the technology and accelerate commercial rollout.

Looking Ahead: Heat for Everyone, Forever

Green Therma's vision is simple yet profound: unlock Earth's endless geothermal potential to provide affordable, reliable, zero-emission heat anywhere. By drawing on oil-and-gas expertise in drilling, completion, and insulation — combined with modern closed-loop innovation — they're creating a pathway to resilient energy systems.

As the world races toward net-zero, breakthroughs like this remind us that powerful solutions often lie right beneath our feet. The Groß Schönebeck project isn't just a test — it's a bold step toward a future where deep Earth heat powers communities sustainably for generations.

Stay tuned for updates on the 2026 operations and results. The era of scalable geothermal is heating up.

About the Author: Alphaxioms Geothermal News tracks the latest in renewable geothermal innovations worldwide.

Source: GreenTherma

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