At Green Therma, we are on a mission to transform how the world harvests Earth’s energy by making deep geothermal heat accessible, reliable, and scalable for communities, businesses, and cities everywhere. Our breakthrough Heat4Ever™ solution and patented DualVac™ technology capture renewable heat deep beneath the surface and deliver it directly into existing district heating networks with a very low above-ground footprint.
Traditional geothermal systems often depend on specific underground water reservoirs or require multiple wells, complex infrastructure, or electric heat pumps to boost temperatures. Heat4Ever™ is different: a single well is drilled 3–5 km down and extended 3–5 km horizontally, and a closed-loop system circulates fluid through our DualVac™ insulated pipes, which preserve heat much like a thermos. The resulting thermal energy is transferred efficiently to the district heating network via a heat exchanger — eliminating the need for large heat pumps and simplifying the system. Above ground, only a small technical building is needed for the heat exchanger and controls.
Low footprint, lower risk, predictable output
This innovative design reduces geological risk, minimizes maintenance, and delivers predictable, resilient heat year-round — independent of weather fluctuations and unaffected by fuel price volatility. Heat4Ever™ systems are engineered for longevity, with components designed to last for decades and deliver steady heat with minimal operational complexity.
Green Therma was founded in 2023 by a team with deep expertise in drilling, subsurface engineering, and energy infrastructure. Drawing on decades of experience across sectors, we developed a technology that works in a wide range of geological conditions and can be scaled to meet diverse heat demands, from industrial campuses and greenhouse operations to municipal district heating grids.
Aalborg demonstration project (EUDP-backed)
Our first full-scale demonstration project in Aalborg, Denmark, backed by the Danish Energy Technology Development and Demonstration Program (EUDP), will showcase the deployment and integration of Heat4Ever™ into a real-world district heating system. The success of this project will establish a new reference for geothermal heat production in Denmark and beyond.
By combining cutting-edge engineering with the Earth’s constant heat, Green Therma is unlocking a future where geothermal energy plays a central role in secure, local, and renewable heat supply — with minimal surface presence and no need for auxiliary heat pumps.