The hydroelectric Projects of Public Power Corporation in Nestos river
PPC, is the largest electricity producer in Greece, built during the decade of the 90 on the River Nestos two hydroelectric power plants «in-line»: the hydroelectric plant «Treasure» with total power 384 Mw (3 units of 128 Mw) and hydroelectric plant «Platanovrysis» (2 units of 58 Mw) Hydropower plants are on the river Nestos in Drama EE in the Municipality of Paranesti, its construction lasted more than a decade and there were invested financial resources of around 1 billion euros at historical rates. Hydropower plants of PPC Nestos river classified as multipurpose projects serving power needs, irrigation downstream rural areas and flood protection. The total average energy output of projects is around 800.000.000 Kwh annually, employ 50 permanent workers and operate a certified environmental management system ISO 14001. Projects using hydrodynamic Nestos river which springs from Bulgarian territory (where called Mesta) and flows into the Thracian Sea. River water The amounts that result in Greek territory were set previously by intergovernmental agreement between the two countries. Note that a number of bilateral agreements for the management of transboundary rivers is very limited worldwide.
Combined cycle power plants in Komotini. This station type is 2-2-1 that has two gas turbines, two heat recovery systems and a steam turbine. As fuel used is natural gas or diesel for backup. Heat recovery systems are vertical layout without additional firing. For optimum operation of the station has selected steam turbine with three pressure stages. The net station output power is 476,3 MW. The design of this plant was based on the climatic conditions prevailing in the region and the main criterion optimal plant operation. A combined cycle power station has a lower installation cost than a thermoelectric since it is a smaller and simpler installation. Also, the maintenance costs are lower and personnel costs borne by the firm less than a thermoelectric because the operation of the combined cycle power plant is automated and requires less staff. Each turbine exhaust are being discharged to the environment either through the heat recovery system or through the bypass tube. Of course, the concentration of exhaust products must be that specified by the relevant European regulations. For example,for natural gas,the concentration of NOx can not exceed 50 mg / Nm3 dry flue gas and 15% O2 with no water spray, for all operating conditions. Moreover, a wet natural draft cooling tower used to cool 25520 m3 / h of water in the main condenser and additional 2250 m3 / h for auxiliary systems. In the area of plant there are four water treatment plants, which are: – Station water softening. – Station for feed water production without metals – Station determining the desired properties of the feed water and additionally chemical processes – Biological waste treatment plant