The Successful Geothermal Risk Mitigation System in France from 1980 to 2015

摘要

The late 1970s saw the establishment in France of a heat producing industry based on the use of geothermal resources located 2000 meters under the Ile de France region. This technology was invented by French engineers was then rolled out in several French regions, especially Aquitaine. This home-grown source of energy at a time when the price of fossil fuels was exploding, offered temperatures of 60 to 85°C, therefore directly usable for heating buildings with or without shared heating networks. These low temperature geothermal resources were regulated from 1978 by a decree allowing its use, as in France the ground below the surface belongs to the Stat. This law allows the use of geothermal resources and requires obtaining a Prefectural Act to explore and exploit the resources. At the time, the Ministry for Industry successively initiated a Geothermal Committee before being transferred to the administrative supervision of the newly created environment agency later to become ADEME (French agency for environment and energy management). To encourage this expansion, a Short Term Fund was set up prior to 1981 to cover the geological risks linked to the performance of deep drillings. After 1982, a continuation of the Short Term Fund was agreed as well as the setting up of a Long Term Fund, managed by the SAF Environment subsidiary of the Caisse des Depots et Consignations, to cover the operating life of the geothermal works for 15 years. These are the measures that made the roll out of low temperature geothermal energy a success unrivalled worldwide. These two funds allowed close to 500 MW of installed thermal power to be set up, representing a cumulative saving in fossil fuels of some three million tons and six million tons of CO2 emissions avoided over a 35 year period. For the Short Term Fund, 200 M{EUR} of investment spending was guaranteed during the drilling phase, with only 5 M{EUR} financed by the authorities. Over the Long Term Fund, 260 M{EUR} worth of investment was guaranteed, including not only the cost of the drilling works but also of the geothermal loops for 63 operations nationwide. The payments made by the State came to 8 M{EUR}, meaning that for every {EUR}1 put up by the State, {EUR}33 of investments were covered for a period of 25 years.