CI-81-11-3 -- A Review of Two Existing Low Temperature Geothermal District Heating Systems in Europe ✓ Most Recent

Geothermally heated water occurs virtually throughout France in both sedimentary basins and in tectonic faults located in more mountainous regions. Fig. 1 defines the general geothermal resources throughout the country as well as identifying temperatures encountered during geological evaluation of the two sedimentary basins--the Parisian and the Aquitaine Basins. These data were accumulated during 1974 and 1975 as a part of a feasibility study investigating the occurrence of petroleum, and verified through test boreholes. Identified geothermal resources in France have been estimated at 4.42 x 10¹¹ MWh.

Surface manifestations of geothermal activity occur frequently in several areas of the country, as noted. Resources in these locations that have been developed.

Since few areas produce steam in quantities necessary to generate electricity, the bulk of the geothermal heat is best suited for low temperature process heat or district heating. The problem of developing low temperature geothermal sources is to correlate nearby population centers with known geothermal resources, because the cost of transporting this energy over long distances is significant.

The oil embargo of 1973 provided the impetus to exploit the postulated geothermal energy and test the accuracy of the assumptions used in the geologic survey. The results have thus far been quite good.