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German Geothermal Association releases directive for seismicity in geothermal projects

Geothermal power plant in Landau, Germany (source: flickr/ webguy63, creative commons)
Alexander Richter 9 Dec 2011

The German Geothermal Association publishes a set of guidelines as part of a Directive intended to provide comprehensive monitoring of potential seismicity in geothermal projects.

The German Geothermal Association has published a set of guidelines as part of a directive that is intended to provide comprehensive monitoring of potential seismicity in geothermal projects.

In the now published Sheet 1 is to provide guidance for operators to set up a monitoring scheme for geothermal project that allow a controlled operation of any facilities.

The Directive GTV 1101 (Sheet 1) “Seismic monitoring” does not specify when the monitoring of a project is useful or necessary, but only describes what needs to be done to implement it. The technical requirements for instruments to be used are described, as well as the required equipment of the monitoring networks. The Directive distinguishes between two monitoring networks. While the immission network will serve to assess the possible adverse effects of shocks, the emission network informs of the existing natural and induced seismicity in one location.

The triggering of seismic events of human intervention in the subsurface is understood under “induced seismicity”. This can be caused not only by deep geothermal projects, but are reported as well from they the construction of dams, mining operations or the construction of tunnels. Nevertheless, events of this kind in the past, particularly in the cases of geothermal projects initiated discussions. Prof. Dr. Horst Rueter, president of the section “Geothermal Association” of the German Geothermal Association (GtV geothermal), said: “Worldwide, induced seismicity through geothermal projects have so far not triggered any structural damages on buildings, infrastructure or even put human lives at risk. Furthermore, induced seismicity is in principal predictable and controllable.” But therefore the planning and implementation of a geothermal project needs to occur under the method of “controlled operation”. ” This approach, as developed by the German Geothermal Association, includes a monitoring concept for natural and induced seismicity, and a reaction scheme. It is part of the Association’s position paper on the topic of “induced seismicity” of July 2010.

The Directive GTV 1101 (sheet 1) “Seismic Monitoring” thus forms a cornerstone for ensuring the controlled operation of geothermal plants. So that they can simultaneously be the basis for agreements between authorities and operators, on how to deal with the possibility of induced seismicity. To accompany the issue of seismicity in geothermal projects comprehensively, the Association is planning drafts of subsequent sheets of the Directive.

The Directive GTV 1101 (sheet 1) “Seismic Monitoring is available via the Association’s website, www.geothermie.de (in German only) under “Publikationen”, as well as under this >link (pdf, in German only)<.

Source: Release of the German Geothermal Association by email