New Energy World™
New Energy World™ embraces the whole energy industry as it connects and converges to address the decarbonisation challenge. It covers progress being made across the industry, from the dynamics under way to reduce emissions in oil and gas, through improvements to the efficiency of energy conversion and use, to cutting-edge initiatives in renewable and low-carbon technologies.
Canada-based developer Eavor has begun delivering geothermal heat and power using an innovative closed loop system at its ‘world first’ commercial-scale operation in Geretsried in southern Germany.
It is unlike traditional geothermal systems which use convection and require direct wells to hot aquifers or fracking – at risk of seismic activity. Instead, the Eavor-Loop is a ‘closed-loop geothermal system’ which consists of multiple lateral well bores connected to vertical bores at either end. Then a proprietary working fluid is circulated in the system to retrieve heat via conduction, creating a ‘radiator in reverse’ below ground, where the working fluid circulates naturally due to the thermosiphon effect – without using an external pump.
The Eavor-Loop system is described as useful in a range of geologies, without the need for drilling, sourcing water or water treatment, and is claimed to minimise maintenance and reduce operating costs compared to other geothermal technologies.
The project was funded by the European Investment Bank, which provided €45mn under the InvestEU programme, along with a €96.1mn grant from the EU Innovation Fund, and €130mn cofinance from a consortium of international banks, including the Japan Bank for International Cooperation, Mizhuo Bank and ING Bank.
The Eavor-Loop system is seen as a ‘blueprint for wider European and global roll-out in the search for stable, locally-derived energy sources across a wide range of geologies, with minimal land and water usage’, claims Fabricio Cesario, Head of Project Delivery and Operations at Eavor.
Eavor’s project partner, OMV, formerly known as the Austrian Mineral Oil Administration Stock Company, ‘contributed substantial operational know-how’, according to Berislav Gaso, Executive Vice President, Energy.
A pilot Eavor-Lite project has been operating in Alberta, Canada since 2019.
How the project was developed
The Eavor-Loop system resembles a giant underground radiator, and involved drilling two vertical wells to a depth of 4,500–5,000 metres, each with six lateral wells (3,000–3,500 metres long), connected below ground using Eavor’s active magnetic ranging tool. These lateral wells are said to be some of the longest in the world, with 16 km of continuous wellbore per pair. The radiator was then filled with a proprietary working fluid.
The working fluid is heated by the underground rock and rises to the surface where the heat is extracted for direct use, after which it returns below ground in a closed loop. The system has a thermal output of 64 MW, offering district heating of up to 20,000 homes, saving up to 44,000 t/y of CO2. It also generates power via an onsite power station connected to the German grid.
The system is said to emit fewer greenhouse gases than conventional geothermal systems because there is no need to reinject fluids or use pumps.
Eavor says it has also made significant progress on a second geothermal project in Hanover, Germany, targeted to supply 15–20% of demand for district heating in Lower Saxony, where a seismic survey has been completed. Work is also underway on other exploratory licences across the globe.
