Objetivo The project aimed at demonstrating the operation of an 860 kW two KSB pump system (0,76 m3/s and 2 m3/s) in reverse operation, exploiting a 44 metre head and producing 4,100,000 kWh per annum. The installation was to be computerised in order to optimise river flows and energy production, used in providing the maximum possible autonomy to Kalavryta Ski-Center in an environmentally respectful manner involving no dam thus capturing the available water supplies in each period of the year. A grid connection was also provided for sales of surplus electricity production and emergency purchases, thus allowing the use of asynchronous generators. The plant installation was part of the Ski-Center's development plan involving major energy consuming invetsments in snow-making and water supply facilities.The initial estimation gave a cost of 166 million (1989). A preliminary feasibility study (1990) specified this cost between 220 and 280 million Drs depending on the particular solution selected for electrical connection between the plant and the Ski-Center. The final construction studies (May 1991) specified a cost of 244 million Drs for the civil engineering works and 120 million Drs for the electromechanical equipment.The budget was determined using prices defined by the Ministry of Public Works upon which the constructors would give particular discounts. A survey undertaken by the Ski-Center during early summer of 1991 indicated that a 40% discount on the civil engineering works budget was to be expected keeping unelastic the electromechanical equipment budget. Thus the final cost was determined to be no less than 280 million Drs.Initial estimation and final budget differences were imposed partly due to the change in micrositing of the plant's location. Due to public opposition, the investor was forced to locate the plant 4 km south of the initial location. This imposed a respectively longer water open channel for achieving the same head, therefore increasing the cost. Keen efforts were made to reach agreement however never achieving it.Furthemore, the plant was to be located on public forest land and although the regional Forest Agency issued the required Permit, the central Ministry at Athens never signed the required Planning Contract which would enable the investor to obtain the installation Permit from the MInistry of Industry and Technology. Much effort was put towards this direction, nevertheless unsuccessfully. In the meantime three general election periods between 1989 and 1990 in Greece made the situation even more difficult. Law 1262/82 which was accounted by the investor regarding expected financing was altered by Law 1892/90, inflation boomed and interest rates rose. Construction work price index rose higher than inflation rates, the price at which the PPC buys electricity from self producers did not rise at the expected rates and last, but not least, an extended drought period in the region forced the Ski-Center to almost no-operation for a two year period, thus having no income surplus for the planned development expansion.A future period of a more favourable economic chance for both the investor as well as the national economy is expected in order to implement the above plan.The power plant was to be located at Agridi on river Krathis' basin 15 km south of Akrata and north of the Ski-Center facilities in northern Peloponesos in Greece. The plant is approached by a secondary route of ttoal length approx. 2900 m. branching out of the main route joining Akrata with the village of Zarouhia and was to be constructed on public "Forest land".The 30 m stem diversion dam of height no more than 1,5 m flooding a 1000 m2 area upstream incorporates an orthogonal channel covered by a grid consisting of accordingly spaced metal bars so as not to allow major objects to insert the channel. Sand and gravel are collected in a sink water trap before existing. It captures a maximum flow rate of 2.8 m3/s. Flood flows evaluated as high as 230 m3/s are safely led over a spillway. Sluice gates isolate the diversion dam. A 20 m stem secondary dam for flood protection would also be constructed a few metres downstream.The water is thus led to the 2,8 m3/s max. capacity, 1295 mlong open channel paralleled by a 4 m width service road leading it to the penstock forebay. The max. flow depth is 0,97 m with free height to the channel edge of 0,33 m. The penstock forebay is 3,60 m deep having a 100 m3 safety volume under the open channel outflow. The 83 m long, 1048 mm diameter penstock leaves the forebay from the basin and lies on a number of concrete bases before branching in two at the plant's level by the river basin, 44 m lower. The electromechanical equipment is housed in a 213 m2 grounted and fire protected building.The plant involves the reverse operation of two KSB pumps, a 230 kW RDL 400-390 B and a 630 kW RDL 700-590 B. Two penstock branches of 500 mm and 600 mm size, allow the base unit to operate between 0,50-0,76 m3/s and the peak unit between 1,4-2,0 m3/s. Starting of each unit is achieved by allowing the asyncrhonous generator to rotate to synchronous speed (50 Hz) by means of a bypass valve locked at the appropriate position before closingthe power switch connecting to the PPC grid. Once connected to the grid, the throttle valve opens gradually while the bypass closes respecfully. The units require a 24 hr period of the preset minimum operation flow to be detected before engaging. The throttle valves ensure that the water level at the penstock forebay never drops below threshold, each unit maintains a minimum instantaneous power, a stable condition is maintained around a balance point avoiding continuous control oscillations as well as maximum energy production. The plant is protected by disengaging the units upon PPC errors in the grid, penstock forebay level drop below threshold, water leakage detection from the forebay to the plant installation or electrical error of either of the units or the electrical boards. A 20/0.4 kV, 1250 kVA transformer provides connection to the medium voltage grid. Programa(s) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador HELLENIC AGENCY FOR LOCAL DEVELOPT AND GOVERMNT Aportación de la UE Sin datos Dirección OMIROU STREET 19 10672 Athens Grecia Ver en el mapa Coste total Sin datos
