99% of our planet is hotter than 1000 ° C, but we hardly use this heat. To be precise, less than one percent of the energy produced globally comes from geothermal sources. This might be surprising, especially in the context of the energy transition and the global striving for CO2 reductions. The reason why geothermal energy has not yet caught on is the high investment costs. In addition, the risk of not finding the desired conditions during the excavation and therefore having to abandon the project does not help the popularity of geothermal energy. But that does not mean that this cannot be changed. On the contrary.
Today's geothermal energy
Traditionally, geothermal energy is utilized by drilling two shafts of up to 5,000 meters into the subsoil. These two boreholes are not connected directly and need to be linked through water-bearing rock layers (aquifers). Unfortunately, aquifers do not occur everywhere naturally.
If aquifers exist, however, those water-bearing layers need to be broken up further using water pressure. This method is called fracking and aims to optimize water flow. But fracking carries risks. On the one hand, the splitting of the rock layers can trigger strong earthquakes. On the other hand, there is always uncertainty whether the rock can be made sufficiently water-bearing. If this is not the case, the drilling was in vain.
Tomorrow's geothermal energy
Future projects of deep heat utilization will use a closed water cycle (closed-loop geothermal system) and reach depths of up to 10,000 meters. The additional depth results in significantly higher temperatures (up to 300 ° C), leading to greater energy output. Using a closed-loop system will also guarantee the project's success to 100% regardless of geological conditions. The reason is simple: the heat exchange in a closed system does not depend on the existence of aquifers. Allowing geothermal energy to be feasible everywhere and risk-free.
The idea of closed-loop geothermal energy is not new and was first introduced in 1979 by Kurt Brunnschweiler, an ETH engineer. There are currently few start-ups and companies taking on the challenge of geothermal energy. One of the challenges these companies are facing, is the inexistence of suitable drilling technology. For this reason, we at HAMMERDRUM are outstandingly motivated to develop a robot that can efficiently and accurately access the depths.