Canadian company Eavor has developed a geothermal technology capable of extracting heat from deep, dry rock formations and is bringing a system into commercial operation for the first time at a facility in Geretsried, Germany.
The solution has been designed to generate electricity and supply district heating, extending the reach of geothermal energy to regions that lack natural hot water reservoirs.
The system relies on what Eavor calls the Eavor Loop — a closed-circuit configuration that uses advanced drilling techniques to access heat stored in subsurface rock formations. The technology could represent a viable alternative to fossil fuels, particularly in cities that currently burn natural gas or coal to heat buildings.
The choice of Geretsried carries particular significance. Approximately 15 years ago, the city had already attempted to develop geothermal energy through conventional methods. Those drilling operations, however, failed to locate sufficient quantities of hot water to make the project commercially viable, leaving the city dependent on natural gas for heating.
Eavor is now pursuing a fundamentally different approach. Rather than searching for natural hot water reservoirs, the system draws on heat stored within deep rock formations themselves. “Our primary objective is to bring geothermal energy anywhere, everywhere,” said John Redfern, Chief Executive of Eavor, adding that “commissioning the first commercial project in a location where conventional technology failed is a way to demonstrate the potential of the new system.”
The system functions as a large, closed subterranean circuit. Two vertical wells are drilled to a depth of approximately four kilometres, from which a series of horizontal branches extend outward, increasing the surface area in contact with the hot rock. Water circulates through the circuit, absorbing heat from the rock formations. When it returns to the surface, the heated water can be fed directly into district heating networks or used to generate electricity.
A key distinction from certain other geothermal extraction techniques is that the Eavor Loop does not rely on fracturing rock by injecting high-pressure fluids into the subsurface. Instead, the system uses the circulation of water within a sealed circuit to capture naturally occurring heat. The Geretsried project will comprise four circuits, each consisting of two vertical wells and approximately a dozen lateral branches.
Geothermal energy still accounts for a relatively small share of the global renewable energy mix. One of its principal constraints has been the requirement for favourable geological conditions, such as the presence of natural hot water reservoirs. Advances in drilling technology, however, may alter that picture. The International Energy Agency (IEA) notes that new techniques now allow operators to reach greater depths and exploit heat in regions previously considered unsuitable for geothermal generation.
According to IEA Executive Director Fatih Birol, geothermal energy has historically been a niche source concentrated in a small number of countries. With the development of new technologies, however, it could begin to contribute more meaningfully to the global energy system. For Germany, that prospect carries particular weight. The country has been reducing its dependence on fossil fuels and, since Russia’s invasion of Ukraine in 2022, has intensified efforts to cut its reliance on imported natural gas.
The heating sector represents one of the central challenges of that energy transition, given that many district heating systems continue to burn fossil fuels. Should the Geretsried project prove successful, however, the model could be replicated across other cities — using centralised geothermal plants to produce heat and distribute it through pipeline networks to homes, businesses, and other buildings.
The technology has already attracted interest elsewhere. Eavor has secured a contract to supply heating to the city of Hanover, Germany, which has a population of more than 500,000 and is gradually phasing out coal. In Japan — a country with considerable geothermal potential that has so far exploited only a fraction of it — Chubu Electric Power Company has also invested in Eavor’s technology.
The international interest reflects the technology’s potential to make geothermal energy less dependent on the specific geological characteristics of individual locations. Rather than requiring large natural hot water reservoirs, the model seeks to harness the heat present in deep rock formations wherever they exist.
Source: Diário Económico
Original article: https://www.diarioeconomico.co.mz/?p=536652
