Zlatoličje power plant: the number one power plant in terms of energy generation
This power plant generates more than a fifth of all the electric power generated by Dravske Elektrarne Maribor and makes use of the energy potential of the Drava River between the cities of Maribor and Ptuj where the river turns into a flatbed. Due to its location, it has been designed as a channel-type power plant.
The Zlatoličje HPP makes use of the 33 m head and after refurbishment between the years 2007 and 2012, generates annually 577 GWh of electricity with a threshold capacity of 126 MW. The power plant, built between 1964 and 1969, has a supply and discharge channel separate from the riverbed, a 4,5 million m3 reservoir and a dam structure in Melje near the city of Maribor.
The reservoir is 6,5 km long and lies entirely within the area of the city of Maribor. A lateral embankment with concrete lining preventing leakage of water into adjacent lower lying areas was built alongside the Melje industrial zone. The dam structure consists of six 17 m wide spillways with radial gates and top flaps. The spilling capacity of the dam is 4200 m3/s. A small hydroelectric power plant has been installed in the Melje dam structure.
The 17,2 km long supply channel is trapezium shaped and partially buried, while the majority of it runs in a dike raised above ground level. The side and bottom walls are coated with a waterproof concrete lining with. At the mouth of the canal, a spillway to the Drava riverbed is located, preventing any dangerous rise in water levels. The high-rise powerhouse in Zlatoličje has two overhead travelling cranes. The Kaplan turbine units are vertical and two main transformers are located outside the powerhouse. The plant is connected to the Cirkovce substation via a double 110 kV transmission line. At the intake and outlet, cranes are installed for the placement of stoplogs for maintenance. The intake crane also serves for the cleaning of the trashracks.
The discharge channel with a length of 6,2 km is also trapezium-shaped and buried deeply. Downstream from the powerhouse, a 300 m portion of the discharge channel is lined with concrete plates. Just before Ptuj, water is discharged back into the Drava River.
After refurbishment the capacity of the Zlatoličje HPP has increased by 12 MW which has been achieved primarily by installing new, high-quality primary unit equipment.