La place du transfert d'énergie par pompage dans le parc de production d'E.D.F. et l'aménagement de Grand'Maison

Share of energy transfer by pumping in EDF's park of generating facilities and development of Grand'Maison

Electricité de France Chef adjoint des Services Etudes Région d'Equipement Alpes-Lyon

Abstract

Part 1 : The Economic approach to energy transfer The paper explains the economic value of pumping, first by recalling the characteristics of demand for electricity, i.e. its daily, weekly, monthly and random variations. It also recalls the characteristics of thermal generation facilities and their cost of production. It then spells out the "direct" method for optimizing the park of generating facilities and shows the resulting availability of low-load hours. Energy transfer by pumping can then be justified : comparison of pumping with competing systems, methodology of pumping efficiency studies, economic value of the different pumping modes : seasonal, weekly or daily. Part I ends with the presentation of the current and projected programme relating to pumping. Part 2 : The Grand'Maison development Grand'Maison is a twin development with a 1200 MW plant, equipped with reversible turbines and a 600 MW plant equipped with Pelton turbines, making it the most powerful hydro-electric development in France. The upper reservoir capacity : 132 h m3 is formed by a rockfill dam with a vertical earth core ; its height is 160 m and volume 12,5 h m3. The lower reservoir is enclosed by a 42 m high alluvium dyke, sealed upstream. The two reservoirs are separated by a maximum head of 955 m. The circuit comprises a 7 km gallery bored by a tunnelling machine at a diameter of 7.70 m and three forced flow conduits installed in tilted shafts of length, 1500 m and diameter, 3.60 m. A 160 m long underground cavity houses the eight 150 MW reversible sets. Above it is the Pelton plant, with four sets of identical power (150 MW) : The planned commissioning dates of this development are between end 1984 and end 1985