GRANDE DIXENCE TECHNICAL DOCUMENTATION GRANDE DIXENCE TECHNICAL DOCUMENTATION CONTENTS THE GRANDE DIXENCE 5 HYDROELECTRIC COMPLEX 6-17 GRANDE DIXENCE 8 PANORAMIC VIEW OF THE FACILITIES 10 LONGITUDINAL PROFILE 16 COLLECTING WORK 18-57 Z’MUTT PUMPING STATION 20 STAFEL PUMPING STATION 32 FERPÈCLE PUMPING STATION 40 AROLLA PUMPING STATION 50 STORAGE 58-75 THE GRANDE DIXENCE DAM 60 PRODUCTION 76-99 FIONNAY POWER PLANT 78 NENDAZ POWER PLANT 86 BIEUDRON POWER PLANT 94 INFORMATION 100-104 GRANDE DIXENCE SA PARTNERS 102 GRANDE DIXENCE SA SHAREHOLDING PORTFOLIO 103 CONTACTS 104 THE GRANDE DIXENCE HYDROELECTRIC COMPLEX Grande Dixence is not only the tallest gravity dam in the world, it is also a masterpiece of technical sophistication and daring devoted entirely to energy. Standing shoulder to shoulder with the highest mountains in Switzerland's Valais region, the structure is the keystone of a vast hydroelectric complex which includes five pumping stations, over 100 km of headrace tunnels cut into the rock and three power plants. Come and discover the Grande Dixence complex! The Grande Dixence dam in the Val des Dix (VS) GRANDE DIXENCE Grande Dixence is not only the tallest gravity dam in the world, it is also 9 HYDROELECTRIC COMPLEX a living legend. Level with the highest mountains in the Valais, this structure is a mas- terpiece in technical skill and audacity channelled into energy. At first sight, you will be astounded by the 285 m of concrete towering above you; once you reach the top of the facility, the stunning view of the Lac des Dix and the valley will take your breath away. The top of the dam forms a gigantic panoramic terrace 15 m wide and nearly 700 m long at an altitude of 2,365 m. Grande Dixence was built in 1961 to replace the first Dixence dam, which is now at the bottom of the Lac des Dix. It took over 10 years to build this new structure, which is located in a vast hydroelectric complex completed in 1965. The reservoir holds all the water from a catchment area of 420 km2 half covered by glaciers. It is these 35 glaciers which, via 75 water intakes, 5 pumping stations (Z'Mutt, Stafel, Ferpècle, Arolla and Cleuson) and 100 km of tunnels, feed the Lac des Dix. The 400 million m3 of water stored behind the Grande Dixence dam represent 20 % of the electricity generated in Switzerland. To make the hydraulic force of the Lac des Dix as profitable as possible, Grande Dixence drives water through its turbines at two levels. The first is at an altitude of 1490 m in the Fionnay plant. The second is level with the Rhône, 1000 m lower at the Nendaz plant. To transform this vast quantity of water into electricity and harness this tranquil force into billions of kWh, the Fionnay and Nendaz power stations work in relay. The tallest gravity dam in the world PANORAMIC VIEW OF THE FACILITIES POINTE DUFOUR 4634 m GORNERGRAT 3090 m MISCHABELS MATTERHORN 4478 m MONT COLLON 3637 m MONT-BLANC DE CHEILON 3870 m ROSABLANCHE 3336 m DENT BLANCHE 4357 m LIFT HEIGHT SIERRE GRAND COMBIN 4314 m LE RHÔNE SION CHANDOLINE VISPA LIFT HEIGHT BIEUDRON LA BORGNE ZINAL NENDAZ LA NAVIZENCE CLEUSON EVOLÈNE VERBIER LA DRANSE GRANDE T FERPÈCLE DIXENCE AT LIFT HEIGHT SIERRE CAPACITY LAC DE MAUVOISIN AROLLA ZERM LE RHÔNE FIONNAY FERPÈCLE 1896 m STAFEL Z’MUTT LIFT HEIGHT SION CHANDOLINE VISPA POWER BIEUDRON LAC DE MOIRY LA BORGNE ZINAL NENDAZ LA NAVIZENCE EVOLÈNE CLEUSON HEIGHT CAPACITY VERBIER LA DRANSE GRANDE T FERPÈCLE DIXENCE AT AROLLA ZERM FIONNAY LA NAVIZENCE STAFEL Z’MUTT CATCHMENT AREA HEIGHT LIFT HEIGHT LA BORGNE HEADRACE GALLERY LA PRINTZE PENSTOCK DAM LAKE POWER POWER POWER LE RHÔNE PRODUCTION PLANT SIERRE SION PUMPING STATION GRANDE DIXENCE HYDROELECTRIC COMPLEX 17 LONGITUDINAL PROFILE With the current installations at Fionnay and The energy produced across all the Grande Dixence- Nendaz, the Grande Dixence complex produces a Cleuson-Dixence facilities reaches approximately 2 total power output of 800 MW. The Bieudron power billion kWh per year, which corresponds to the ave- plant enables this power output to be increased by rage annual consumption of 400,000 households. 1,200 MW, thereby taking the total power output of the complex to 2,000 MW. Like other hydroelectric Grande Dixence SA does not stop at using a renew- facilities, the main purpose of Cleuson-Dixence is to able energy source. The trustee of an exceptional provide power instantly, on demand. In just 4 minutes, natural reserve, it has made firm commitments to the installation is able to provide the network with a policy of sustainable development. This has been power equivalent to that of a nuclear power station ! undertaken to ensure the use of natural resources COLLECTING WORK is constantly optimised and to limit the actual or possible impact of its installations on the environ- STORAGE ment. The energy produced by Grande Dixence is certified by several environmental labels. PRODUCTION 2496 m 2364 m 2240 m 312 m 212 m 470 m 470 HEIGHT m POWER 78 165 m LIFT HEIGHT LIFT HEIGHT 212 m HEIGHT 1883 m LIFT HEIGHT LIFT HEIGHT m8 1008 FERPÈCLE 1896 m LIFT HEIGHT POWER POWER 1200 MW POWER RHÔNE COLLECTING WORK The conveyance network collects water from a 420 km2 reservoir bordered by the Mischabel, Matterhorn and Mont Gelé mountains, two thirds of which is covered by glaciers. Through 100 kilometres of galleries, including a main tunnel which is 24 kilometres long, at an altitude of 2400 metres in the heart of the mountain, 35 glaciers supply the facility's raw material via 75 water intakes and 5 pumping stations. Together they supply on average 500 million m3 of water every year. Inlet of the Vouasson tunnel in the Lac des Dix PUMPING STATION Z'MUTT Set at the foot of the Mattertal, the Z’Mutt pumping station (alt. 1972 m) is the most powerful within the Grande Dixence complex. It is fed by water from the Bis and Schali glaciers which rise above the Visp river, and from the Gorner glacier. Four pumps with a total power of 88 MW are used at Z'Mutt to pump around 140 million m3 of water every season. This water is pumped to a penstock which carries it to the Trift tunnel (altitude of 2400 metres) in the main collector. The impact of the concrete on the environment has been kept to a minimum. The only major visible element is the arch dam which crosses the gorge. Apart from the service building, all of the facilities (gravel traps, sand traps and pumping station) are underground. TECHNICAL SPECIFICATIONS AFTERBAY RESERVOIR CONSTRUCTION 1961 - 1964 HEIGHT 74 m CREST 144 m THICKNESS AT THE CREST 3 m VOLUME OF CONCRETE 32,000 m3 CAPACITY 800,000 m3 TYPE Arch dam PUMPING STATION POWER 2 x 30 MW ; 2 x 14 MW FLOW RATE 17.4 m3 / s DISCHARGE HEAD 365 m / 470 m Z’Mutt afterbay reservoir at the foot of the Matterhorn Z’MUTT PUMPING STATION 23 PLAN OF LOCATION 9 6 95 500 300 621 8 2100 2000 22 to Mutt 2100 10 7 5 Z’Mutt pumping station 4 2000 16 1970 13 15 2 3 1900 1970 17 14 Z’Mutt compensating basin Dam of 800000 m3 capacity 1 1900 Stafelalp Z’Muttbach 21 13 18 2000 12 11 1900 Stafel Zermatt Z'Mutt arch dam on the edge of the Mattertal 19 1 ARCH DAM 8 BODMEN COMPENSATING CHAMBER, 15 BOTTOM GALLERY 20 3 2100 100 m 2 Z'MUTT COMPENSATING BASIN, CAPACITY APPROX. 2000 m 16 ACCESS TUNNEL TO DAM USEFUL CAPACITY 9 SCHALI-BIS CATCHMENT 17 DAM VALVE CHAMBER APPROX. 800,000 m3 DIVERSION TUNNEL, Q = 8.0 m3 / s 18 CABLES SHAFT 3 FLOATING WATER INTAKE 10 COMPENSATING CHAMBER TUNNEL 19 SUBSTATION 4 2.30 m Ø CATCHMENT AND OVERFLOW PIPE 20 130 kV TRANSMISSION LINE DIVERSION TUNNEL 11 ADMINISTRATION AND 21 ROAD TUNNEL 5 UNDERGROUND PUMPING STATION CONTROL BUILDING 22 HEADRACE TUNNEL TO THE 6 STEEL-LINED DISCHARGE SHAFT 12 ZERMATT - Z'MUTT CABLEWAY MUTT POWER PLANT (EWZ) TO UPPER MAIN TUNNEL (TRIFT) 13 ACCESS TUNNEL Q = 17.4 m3 / s TO PUMPING STATION 7 BIS SHAFT, STEEL-LINED, 1.35 m Ø 14 BRIDGE Z’MUTT PUMPING STATION 25 LONGITUDINAL AND TRANSVERSAL PROFILES OF Z'MUTT CONDUITS AND SHAFTS 637,00 39,00 1 TRIFT TUNNEL Main pressure shaft 2 STEEL-LINED 1.90 m Ø, LINING 1 2400 THICKNESS 14 - 11.5 mm 3 STEEL-LINED 1.80 m Ø, LINING THICKNESS 24 - 14 mm 16,46 4 HIGH-PRESSURE VALVES 2 x 0.80 m Ø 2300 2 x 0.70 m Ø 5 Z'MUTT PUMPING STATION 6 LOW-PRESSURE VALVES 1 x 1.60 m Ø 429,00 2200 2 x 1.20 m Ø 7 2.00 m Ø INLET VALVE 8 STEEL-LINED 2.30 m Ø GRADIENT 2 % 9 STEEL-LINED 2.30 m Ø 2100 GRADIENT 60 % 198,14 25,00 10 FLOATING WATER INTAKE Intake penstock Steel-lined shaft Schali-Bis 11 Z'MUTT COMPENSATING BASIN, USEFUL CAPACITY 2000 2100 APPROX. 800,000 m3 12 1970 12 SCHALI-BIS TUNNEL 377,00 13 BODMEN COMPENSATING CHAMBER 11 10 13 5 USEFUL CAPACITY, 2000 3 1899 APPROX. 2000 m 14 LINED OVER 246.54 m, 1.35 m Ø 6 LINING THICKNESS 9 mm 7 4 GRADIENT ~ 80 % 44,90 105,63 246,54 15 SCHALI-BIS LOW-PRESSURE VALVES 1900 1 x 1.00 m Ø 15 1 x 1.40 m Ø 9 8 3 2 14 50 55 20 20 80 20 20 95 4,00 5,00 2,30 2,80 3,40 2,30 1,35 1,85 1,90 1,80 2,40 2,30 3,80 2,00 30 30 30 30 30 30 1,50 1,50 2,50 1,50 1,50 1,50 50 4,00 50 50 5,00 Z’MUTT PUMPING STATION 2727 HYDRAULIC DIAGRAM Mischabels Täschalp Findelen 2550 Furgg Obertheodul 2500 Hohwäng Arb Trift 1 2450 2400 2350 2300 Z’Mutt 3 2250 2 2200 Schali Bis 2150 Stafel 2100 Gorner 2050 2000 1950 1900 Z’Mutt 1850 DIAGRAMMischabel OF ZERMATT Täschalp Findelen VALLEY INSTALLATIONS2550 Furgg Obertheodul 2500 Trift Hohwäng Arb 2450 5 Mischabel Täschalp Findelen 2550 1 MAIN DIVERSION TUNNEL 2400 FREE FLOWING TUNNELS INTAKES Furgg Obertheodul 2500 Trift Hohwäng Arb 2 Z'MUTT SYPHON 2350 PRESSURE SHAFTS PUMPING STATIONS 2450 5 2300 3 GORNER SYPHON 2400 Z’Mutt 2250 2350 5 2200 2300 Schali Bis 2150 Z’Mutt 2250 Stafel 2100 2424,35 5 2200 Gorner 6 2050 Schali Bis 2150 2419,26 2000 Stafel 2100 1950 Gorner 5 2050 1900 2000 2066,28 Z’Mutt 1850 7 5 1950 12 2059,42 1900 Z’Mutt 1850 max.