Green light for expansion of geothermal heat project in Riehen, Switzerland
Expansion of district heating network, Riehen/ Switzerland (source: Erdwaerme Riehen/ geothermie-schweiz.ch)
Alexander Richter
8 Nov 2020
With public approval, the planned expansion of the geothermal district heating system in Riehen near Basel, Switzerland can proceeed.
As reported by the local geothermal heating company Erdwaerme Riehen, the way for the construction of another geothermal heating network has been given the green light. The residents’ council of the municipality in the German part of Switzerland approved a corresponding application by the municipality on September 24, 2020. With the end of the referendum period on October 29, 2020, this decision is now final. As the next step, a seismic measurement campaign is to show a clearer picture of the subsurface.
The Riehen geothermal system has been reliably delivering climate-friendly thermal energy to the 8,500 residents of Riehen for over 26 years. For the future, Wärmeverbund Riehen AG (WVR) expects continued high demand. A second well should therefore tap more naturally available thermal water for heat utilization. A feasibility study confirmed the potential and good prospects of success for the project. The drilling to pump the thermal water and the construction of the facility will cost around CHF 20 million (around USD 22 million). In 2026, another 4,000 people can be supplied with climate-friendly energy from Riehens underground.
The municipality of Riehen and IWB share the costs
The costs are shared between the two shareholders of the WVR, the municipality of Riehen and the Basel energy supplier IWB. The Swiss Federal Office of Energy has pledged funding of CHF 1.2 million and has announced a further CHF 5.1 million. The greater involvement of IWB (the share was recently increased from 27 to 50 percent), on the one hand, makes it easier to finance the project. On the other hand, the WVR can better coordinate the operation of the systems and the growing supply network with IWB. This is particularly advantageous with regard to the legally prescribed decarbonisation of the heat supply in the canton of Basel-Stadt. The gradual and partial shutdown of the gas supply is thus optimally coordinated with the growth of the Riehen heating network.
Seismic surveys in 2021
The next steps are seismic surveys to explore the subsurface for “geo2riehen” in summer 2021. These are important to be able to determine the suitability of a later drilling target. If the feasibility of the project is confirmed, the first of two wells could begin in 2023. The WVR works with experts who have valuable experience in deep geological explorations. Those responsible for the project consider the occurrence of a noticeable earthquake to be extremely unlikely. No incidents occurred during the previous wells in Riehen. In order to live up to its responsibility, WVR AG carefully examines all project risks, takes appropriate measures and proceeds step by step throughout the project in order to keep adding new knowledge.
Comprehensive information and the involvement of the Riehen population is very important to the WVR, the Riehen community and IWB. WVR AG is available for questions and will continue to provide in-depth information about each project stage. In addition, it will offer events for the population under the moderation of the independent Risk Dialogue Foundation.
Source: Erdwärme Riehen via our partner site TiefeGeothermie
