The "inventories" of the world's resources were mainly done in the United States and in Europe. But these inventories are often dependent on the data previously obtained from subsurface temperatures from mining and oil&gas drillings, as well as surface manifestations such as volcanism and thermal springs.
The first few reports show resources potential with strategic impacts : 356 GWe in the United States (USGS 2008, national geothermal resource assessment), 100 GWe for Europe (The European HDR project at Soultz presentation, 2004).
In Europe, the main deep geothermal resources are located in Turkey, Central Europe, France, and Italy (Larderello). On the map below, these are the red, pink and brown aeras.
5 km depth temperature european map :
Nevertheless, we believe that inventories should give more consideration to a key parameter in the exploitation of a geothermal resource: permeability. This impacts the potential flow rates of the reservoir rocks and therefore the power potential of the geothermal field.
At TLS Geothermics, we think we need to choose the "play" type of the field that we are looking for prior to launching the exploration campaign, as in oil&gas exploration industry.
For several years, we have been developing a geothermal field concept that integrates four key parameters to identify economic resources: temperature and permeability that characterize the amount of extractable heat, durability and depth for the economic approach.
Taking into account this new concept as well as the surface geothermal heat flux, we made a quick sketch of the probable potential of this concept on a European scale.
Thus, if the 1/1.5M faults are for 5% of them sufficiently permeable to allow an installation of 10MWe every 20 km, then the European potential would be 6.8GWe.
On the international scale, TLS Geothermics is working on assessing the world potential of the Crustal Fault Zone concept using state of the art predictive information technology.
Here is a first insight (not predictive, knowledge based) of a world thermal favorability map.
This map is based on independant large scale lithospheric and crustal thermal models.