Electric Power Industry of Serbia

IndustrySouth-East European INDUSTRIAL Мarket - issue 1/2007

After a long history, nowadays the electric power industry in Serbia has one name Elektroprivreda Srbije. Public Enterprise ”Electric power industry of Serbia” (PE EPS) was established by Decision of the Government of Serbia which entered into force on 1 July 2005. The same year PE EPS was unbundled, transmission activities were separated and two autonomous public enterprises were established - PE Electric Power Industry of Serbia and PE Electric Power Network of Serbia.

100% owned by the Republic of Serbia, PE EPS covers country electric power generation; electric power distribution and distribution system management; electric power trade; coal production, processing and transport; steam and hot water production in combined heating processes; water power utilization and services in river and lake traffic; wholesale trade in fuel and similar products; research and development; design, construction and maintenance of energy and mining plants; design, construction and operation of telecommunication facilities, etc.

Energy facilities

The Electric Power Industry of Serbia is the largest enterprise in the country. The installed capacity of the power plants amounts to a total of 8,355 MW, as follows:

• in lignite-fired thermal power plants 5,171 MW

• in gas-fired and liquid fuel-fired combined heat and power plants 353 MW

• in hydro power plants 2,831 MW

EPS operates three power plants of total capacity 461 MW which are not in the ownership thereof.

The Electric Power Industry of Serbia is the largest producer of lignite in the country, with a potential annual production of around 50 million tons. The coal basins of Kolubara, Kostolac and Kosmet (As of 1 July 1999, EPS does not operate their plants on the territory of Kosmet) are in the direct vicinity of thermal power plants. Supply and sales of electric power to almost 3.3 million customers on the territory of Serbia (without Kosmet) are carried out in the scope of the electric power distribution activities of EPS.

Facilities for electric power generation

Facilities for electric power generation consist Thermal power plants, Hydro power plants and Combined heat and power plants. It is set up in five economic assosiations (PLC) as follows:

Thermal Power Plants

• Thermal Power Plants “Nikola Tesla” plc with main office in Obrenovac

• Thermal Power Plants and Mines “Kostolac” plc with main office in Kostolac

Hydro Power Plants

• Hydro Power Plants “Djerdap” plc with main office in Kladovo

• Hydro Power Plants “Drinsko - Limske” plc with main office in Bajina Basta

Combined Heat and Power Plants

•Combined Heat and Power Plants “Panonske” plc with main office in Novi Sad

In 2004, an amount of 35,089 GWh electric power was produced in EPS’s power plants, which was by 4.7 percent more than in the previous year. An amount of 24,068 GWh, or 68.6 percent was produced by thermal power plants and the rest (11,021 GWh or 31.4 percent) by hydro power plants. The largest electric power production of around 36,900 GWh was achieved in 1989.

In terms of origin, the structure of equipment in power plants is extremely heterogeneous. The equipment is predominantly from East European countries (Russia, Czech Republic, Slovak Republic, Poland, Romania) and former Yugoslav republics. However, in terms of complexity,acquisition value and technological aspect, the Western countries’ share (Germany, France, Switzerland, USA, Japan, England, Austria, Italy) is considerably larger.

Thermal Power Plants

The aggregate capacity of eight thermal power plants with 25 blocks is 5,171 MW, using lignite as fuel. In 2004, an amount of 23,715 GWh was generated by thermal power plants, which is 67.5 percent of the aggregate electric power production of EPS.

Thermal Power Plants (TPPs) are:

Economic Assosiation “TPP Nikola Tesla” Obrenovac consisting of the following subsidiaries:

• TPP Nikola Tesla A (with a total of 6 blocks)

• TPP Nikola Tesla B (with a total of 2 blocks)

• TPP Kolubara (with a total of 5 blocks)

• TPP Morava (with one block)

Economic Assosiation TPP and Mines Kostolac consisting of the following subsidiaries:

• TPP Kostolac A (with a total of 2 blocks)

• TPP Kostolac B ( with a total of 2 blocks

TPP Kosovo (As said, as of 1 July 1999, EPS does not operate its facilities on the territory of Kosmet)

• TPP Kosovo A (with a total of 5 blocks)

• TPP Kosovo B (with a total of 2 blocks)

Back in 1956, block A1 of 29 MW was put into operation in TPP “Kolubara”, which was the beginning of continuous development of the Electric Power Industry of Serbia up to the 90s of the previous century – to 1991, when block B2 of 320 MW was put into operation in TPP “Kostolac B”. The largest blocks are at TPP “Nikola Tesla B” – blocks B1 and B2 with 580 MW available capacity per block.

Hydro power plants

The total capacity of nine hydro power plants with fifty hydro units is 2,831 MW, which makes almost 34 percent of EPS’s total electric power potential. Hydro power plants produced 11,021 GWh in 2004, which makes 31 percent of the total electric power production of the Electric Power Industry of Serbia.

Hydro Power Plants (HPPs) are:

Economic Assosiation HPP Djerdap, plc with its subsidiaries:

• HPP Djerdap I (with 6 units)

• HPP Djerdap II (with 10 units)

• HPP Pirot (with 2 units)

• HPP Vlasina (with 10 units)

Economic Assosiation HPPs Drinsko-limske, plc with its subsidiaries:

• HPP Bajina Basta (with 4 units)

• RHPP Bajina Basta (with 2 units)

• HPP Limske (with 8 units)

• HPP Zvornik (with 4 units)

• HPP Elektromorava (with 4 units)

The first hydro power plants were put into operation back in 1955 – HPP Vlasina, followed by HPP Elektromorava (1954-1957). However, HPP Djerdap is considered to be the Queen of all hydro power plants in Serbia.

Construction of HPP “Djerdap I” began as early as 1964, through joint investment of Yugoslavia and Romania. The first units were put into operation in 1970, and the whole plant was put into operation on 16 May, 1972. The basic activity of this hydro power plant is not only electric power production, but also operation of water locks in the “Djerdap I” and “Djerdap II” system.

HPP “Djerdap I” has two-level water locks (ships enter the chamber and then they are “led” into the end water level of the Danube at the chamber end). In terms of chamber dimensions, these water locks are among the largest ones in the world. The construction of HPP “Djerdap II” officially began on 3 December 1977, and the first units were put into operation in 1985. This hydro power plant consists of: a power plant, water lock, spillway and non-spillway dam, as well as a dam crossing in the middle of which is the border between the two countries. The project allows a possibility for construction of a railroad across the dam.

Hydro PowerPlant Djerdap 1 has a comparatively small dynamic volume, but under the daily operation regime with two peaks and together with HPP Djerdap 2 as a compensating reservoir, it manages to place a major part of generation into the variable part of load diagram. The power plant is a storage plant, with short supply components and backing up (water pipe-turbine-generator-discharge pipe), which enables rapid change of load. The unit capacity is 175 MW.

HPP Djerdap 2 is virtually a compensating reservoir and most of its production is placed in the constant part of the load diagram. It cannot, therefore, take part in the system’s load regulation. It is also limited by navigation requirements (Qmin =2000m3/s) and permitted water level oscillations of 60 cm at the mouth of the River Timok. The unit capacity is 27 MW.

HPPs Zvornik, Bajina Basta and Potpec are power plants with possibilities for daily and weekly water regulation, respectively (Bajina Basta). The smallest regulation possibilities are at HPP Zvornik, due to filled-in storage reservoir. By constructing plants on the section Zvornik - Bajina Basta, the variable operation problem of HPP Zvornik (power plants in a sequence) would be solved. This group of power plants may take part in the system’s load regulation and may also take part in providing the rotating reserve, and they may therefore also use the seasonal regulated waters in the upstream storage reservoirs (Piva, Uvac, Kokin Brod).

HPP Ovcar Banya and Medjuvrsye (among the oldest plants) are, according to their characteristics, actually distribution plants. The size of the installed discharge (40m3/s) compared to the available water pipe (34m3/s), and particularly the sediment filling in the storage reservoir, practically define the production of these plants as a constant part of the load diagram.

Storage hydro power plants

Hydro Power Plants Limske (Uvac, Kokin brod, Bistrica) have an available large storage area and in that sense are very flexible and widely used resource. They may be used practically for all purposes in the system, from regularly meeting the consumption in terms of energy and capacity, through all forms of reserves in the system (also including the cold reserve), up to load regulation in the system and seasonal water regulation. The long water pipe at HPP Bistrica prevents faster load changes, however the existing ones are sufficient.

HPPs on the River Vlasina, given a high degree of installed capacity (Qi =18m3/s) and volume of 107 milions m3, are also plants with a wide spectre of application in the system. Given the performed repumping of waters (PSP Lisina), they may be used for all purposes in the electric power system, including cold reserve.

HPP Pirot with a useful volume of 130 milions m3 and installed discharge of 42m3/s is also convenient for all system purposes. A somewhat longer tunnel reduces the velocity of load change, but does not jeopardise this power plant function (load-frequency regulation).

Reversible hydro power plant

The Electric Power System of Serbia also possesses one specific plant, the reversible hydro power plant Bajina Basta. In the generator operation regime, this plant is practically a hydro power plant with all its advantages – characteristics. In pumped operation this plant has very rigid characteristics. The rate of efficiency of the pumping-turbining cycle is 0.73, which defines this entire plant as a consumer. Water inflow into the upper storage reservoir is insignificant in comparison to the pumped amount of water. These reasons call for rational use of this plant in the sense of the greatest possible commitment of capacity in generator operation in the shortest possible time. Commitment in pumped operation should be adjusted, as far as possible, to the load diagram shape, in the sense of increasing or possibly reducing it, or preventing spillways and facilitating technical minimums of thermal power plant units.

It may be said that, compared to a conventional hydro power plant, a reversible hydro power plant does not use a recoverable resource (apart from taking over spillways). Therefore, there are no conveniences such as free fuel, but it depend less on the hydrological conditions and considerably more on the state of the thermal power plants’ subsystem. The efficiency of storage volume (150 millions m3; 190 GWh) classifies this plant in the list of very convenient and useful ones in terms of providing a part of cold reserve in the system.

Combined heat and power plants

The subsidiaries of Economic Assosiation “Combined Heat and Power Plants Panonske” plc are:

•Combined Heat and Power Plant Novi Sad - with 2 blocks – total available capacity 208 MW

•Combined Heat and Power Plant Zrenjanin – with 1 block – total available capacity 100 MW

•Combined Heat and Power Plant Sremska Mitrovica – with 3 blocks – total available capacity 45 MW

Total capacity of all these Combined Heat and Power Plants is 353 MW and their total annual production amounts to 353 GWh.

Combined Heat and Power Plant “Novi Sad” is a power plant for combined production of electric power, technological steam and heat energy. Natural gas supply is provided through connection to the main gas pipeline, fuel oil is transported by a fuel oil pipeline, while the vicinity of the Danube enables comparatively easy supply of this Combined Heat and Power Plant with required amounts of cooling water.

Based on Public Enterprise ”Electric power industry of Serbia” data.