In the late 1980^th under coordination of Semyon Potashnik (nowadays he takes a position of the Head of Board of Dniprogydroenergo SJSPGC) there were developed and approved by the Ministry of Power of Ukraine the Main Directions of Reconstruction and Technical Re-Equipment of Hydro Power Stations of Ukraine to be implemented during the years 1990-2010.

Necessity to develop the Main Directions resulted from permanently worsening technical and economical performance of the hydro power stations of Ukraine due to considerable obsolescence of their equipment. For example, in the late 1980^th most of the equipment installed at hydro power stations of the Dniprovskiy Cascade were under operation during from 20 to 50 years and were completely worn out. However the implementation of the Main Directions was not launched due to recession suffered by the economy of Ukraine.

The year 1994 was the turning point in the history of the Project. In this year the World Bank, after it had performed feasibility study of the program of reconstruction of the hydro power stations of Ukraine, made a decision to take part in the Project's financing.

Reconstruction of hydro power stations of the Dniprovskiy Cascade is currently performed within the Project of Rehabilitation of Hydropower Stations of Dniprogidroenergo and System Control Framework. The Project is being implemented in two stages. The implementation of the 1^st stage began in 1996, its completion is supposed to be in 2002. The 2^nd stage of the Project will be implemented in 2001-2010.

Main goals of rehabilitation of hydro power stations located on the river of Dnieper are as follows:

• to prolong the term of service life of the hydropower stations for 40 - 50 years;
• to raise reliability and efficiency of the hydropower stations' operation;
• to improve the hydropower stations' performance;
• to raise reliability and safety of operation of hydro technical facilities of HPSs;
• to improve ecological condition of the basin of the river of Dnieper;
• to create modern system of control and monitoring at the unit and station levels of control.

Total cost of works performed within the 1^st stage of implementation of the program of reconstruction of HPSs located on the river of Dnieper amounts to USD 126.8 mln. The Project is financed at the expense:

• of the loan provided by the World Bank that amounts to USD 51 mln;
• of the grant provided by the Government of Switzerland that amounts to USD 9.6 mln;
• of the grant provided by the government of Canada that amounts to USD 0.5 mln;
• of the own funds of Dnipogidroenergo (funds are being obtained from electricity tariff purpose markup) that amounts to USD 65.7 mln.

Estimated cost of works to be implemented during the 2^nd stage of reconstruction of Dniprovskiy Cascade of HPSs totals to USD 385 mln.

In order to implement the 1^st stage of reconstruction, Dniprogidroenergo held international tenders, concluded eight contracts on supply of equipment and technique with such world-known companies as ALFA, ALSTOM, ABB, HAEFELY TRENCH and others. Since the end of 1996 till now there have been implemented large amount of works aimed at reconstruction and partial replacement of worn-out equipment at Kyivska HPS, Kyivska HPSS, Kanivska HPS, Kremenchugska HPS, Dnirpdzerzhynska HPS, Dniprovska HPS and Kahovska HPS. During 1997-2000 there were made capital investments amounting to UAH 204.5 mln.

Installed imported equipment makes up, as on January 1, 2001, 71.4 percent of total equipment to be supplied according to the concluded contracts. At all hydropower stations of Dniprogidroenergo there have been installed 283 units of modern equipment: high voltage switches - 88 units, high voltage disconnectors - 106 units, high voltage instrument transformers of current and voltage - 21 units, governors for generators - 22 units, systems of excitation - 22 units, generating-station circuit breakers - 29 units, systems of control, monitoring and relay protection - 4 units. As on January 1, 2001 there have been purchased equipment with cost amounting to USD 16 mln, obtained and put under installation equipment amounting to UAH 56.991 mln.

In the Project's implementation there take part Ukrainian plants "Turboatom" and "Elektrovazhmash", Institute "Ukrgidroproyekt", staffs of the all hydropower stations of Dniprogidroenergo, many installation, construction, research and other institutions, companies of France, Switzerland and other countries.

In August 2000 there have been held the international tender on purchase of the system of automatic control over safety of operation of hydro technical facilities at Kyivska HPS. This system, after it is put into operation, will provide in automated mode information on condition of hydro technical facilities of the HPS and will increase safety of their operation. Successful completion of this task is special state matter.

The 1^st stage of reconstruction of hydropower stations of Dniprovskiy Cascade, as arranged with the World Bank, will be completed in June 2002. Till this time, in addition to partial replacement of electric equipment (switches, disconnectors, systems of control and excitation of generators), there will be rehabilitated 15 hydropower units including reconstruction of their generators and turbines. New propeller turbines that will be installed are ecologically clean. Thus, possibility of leakage of turbine oil into the river of Dnieper will be completely excluded that will result in improvement of quality of the water.

During the 2nd stage of reconstruction that is supposed to be implemented till 2010 there will be proceeded replacement of hydropower units at the HPSs of Dniprogidroenergo aimed at improvement of its reliability and environmental safety.

It is planed to put into operation the system of control over safe operation of hydro technical facilities of the HPSs of Dniprovskiy Cascade that provides automated control of hydro technical facilities' condition including measurement of linear movements, pressure, level and temperature of water with indication of all information in computer display. Introduction of the system of safe operation of hydro technical facilities of Dniprovskiy Cascade will be implemented in two stages. In the first stage the system will be introduced in Kyivska HPS in 2000 - 2001. During the second stage the system will be introduced in all the remaining HPSs of Dniprohydroenergo. In addition to reliability, safety and prolongation for 40 years of service life of equipment there will be obtained the additional capacity that equals to current capacity of Kyivska HPS or Kahovska HPS.

During following 5-10 years there will be introduced at the HPSs the system of automatic metering of electricity, implemented the program of computerization of operation that will allow to regulate completely and control all technological processes at HPS. In a big way there will be introduced the modern system of diagnostics of equipment as well as the system of control over safe condition of dams.

Additional information concerning the flow of the project of rehabilitation of Dniprogidroenergo's hydro power stations is presented here.