Educational hub

mavcice

mavcice

mavcice

mavcice

1981:
Construction of the Mavčiče hydroelectric power plant began.

1987:
The Mavčiče hydroelectric power plant started operating on July 31, 1986. Just three months later, at the end of October, the second unit was successfully commissioned.

In the Sorško field, under Kranj, the Sava River flows in a valley it carved into highly permeable Quaternary deposits (conglomerate). The depth of the impermeable layer is 120 meters below the surface. Beneath the Sorško field lies a rich aquifer, fed by the Sava River, which serves as a potential water source for central Slovenia. Because the dam is entirely founded on permeable rock formations, it was necessary to install a sealing curtain to the impermeable foundation, which extends along the sides of the dam for a length of 200 meters.

The Mavčiče Hydroelectric Power Plant is a run-of-the-river plant with a dam structure comprising the powerhouse, spillways, and a gravity earth dam. The structural height is 40 meters. Inside the powerhouse, two units (Kaplan turbines) with a combined discharge capacity of 260 m3/s are installed. They produce 38 MW of power at peak production and 62 GWh at the average annual production rate.

The spillway structure consists of two overflow fields equipped with segmental barriers and hinged gate. The dam height is 19.5 meters. The discharge capacity of one overflow field is 1600 m3/s (for a 100-year flood).

The power plant is equipped with two synchronous generators with a rated capacity of 25 MVA and a voltage of 10.5 kV. Each generator is connected to the 110 kV grid through the power plant’s 110 kV switchgear. The power plant is remotely controlled from the SEL control centre, located in Medvode.

2011:
In 2011, the 110 kV switchgear was updated, enabling the connection to the 110 kV grid. By the end of the year, the secondary equipment of the hydroelectric plant was also updated.

medvode

medvode

medvode

medvode

1947:
Construction began in 1947, with both Slovenian and Yugoslavian workers participating in the construction. In addition to the construction of the power plant itself and the dam, workers also built a complex of residential buildings.

1953:
A hydroelectric power plant with a dam was established after the Zbilje Lake was formed due to the rising water level of the river. The dam is located at a point where the Sava River carved rapids into the dolomite, which is largely cracked and filled with cavities. A sealing curtain was installed to the impermeable base, which extends along the sides of the dam to a depth of 27 to 45 meters. The dam structure combines a pillar-shore type. In the direction of the riverbed, there are two overflow fields equipped with double-panel sluice gates of hook design, with a damming height of 17.5m. The flow capacity of the overflow fields is 2400 m3/s.

1964:
The floodgates were raised by 1 meter, increasing the power of the turbines by 11%. In the turbine housings, along the riverbank, two units (Kaplan turbines) with a total flow rate of 150 m^3/s were installed, providing 25 MW of power at peak production and an average annual production of 72 GWh.

1994 in 1995:
The power plant was renovated, and the generators were replaced. It is equipped with two synchronous generators with a nominal power of 13.5 MVA and a voltage of 6.3 kV. The generators are connected to the 6/110 kV switchgear.

2003 in 2004:
The power plant was modernized, and the turbine and secondary equipment were replaced. The 110 kV switchgear was upgraded with a 2×110/6.3 kV transformation and a 110/20 kV distribution switchgear owned by Elektra Gorenjska.

vrhovo

vrhovo

vrhovo

vrhovo

vrhovo

vrhovo

vrhovo

1989 – 1993:
Construction of HPP Vrhovo, located in the field below the Vrhovo settlement, marks the first in a series of hydropower plants in the lower Sava cascade. The dam structure is of concrete-gravity type with a structural height of 27 meters. The power plant operates in a daily-flow regime with accumulation, serving as the headwater reservoir for the lower Sava cascade. After the completion of the entire cascade of hydropower plants on the Sava River, this reservoir will serve as an intermediate balancing reservoir.

Downstream from Radeče, the river valley widens into a broad field where the Sava River transitions into a valley flow regime. The foundation consists of impermeable Permian-Carboniferous shales, overlaid by Quaternary sediment of gravelly-sandy nature, with a top layer of sandy marls and humus. The dam structure is founded on impermeable shales, and the foundation slab is entirely drained. Sealing of the high-water banks is accomplished with thin-wall concrete walls.

The dam structure consists of, in sequence: the power plant, five spillways, and connecting earthen embankments. The power plant houses three units (penstock turbines) with a total flow capacity of 500 m^3/s. At peak production, they provide 34.2 MW of power, with an average annual production of 116 GWh. The spillway gates are equipped with segmental stoplogs and have a damming height of 10.5 meters. The flow capacity of the spillways is 3100 m^3/s, equivalent to a 100-year flood.

The power plant is equipped with three synchronous generators with a nominal power of 14.3 MVA each at a voltage of 6.3 kV. They are connected to the 110 kV grid via a transformer (45 MVA, 119/6.3 kV) with the possibility of connecting.

Sončna elektrarna

2007:
SPP Mavčiče is commissioned

SPP Mavčiče consists of:

• 210 PV modules with a power of 170 W each, installed on the southern facade of the HPP Mavčiče building.
• 210 PV modules with a power of 170 W each, installed on the roof of the HPP Mavčiče building.

The installed capacity of the solar generator is 71.4 kW. The anticipated annual production is approximately 72 MWh of electrical energy.

MFE-Medvode

2008:
SPP Medvode is commissioned

SPP Medvode consists of 280 PV modules with a power of 210 W each, installed on the roof of the maintenance center of HPP Medvode. The installed capacity of the solar generator is 58.8 kW. The anticipated annual production is approximately 60 MWh of electrical energy.

MFE-Vrhovo

2008:
SPP Vrhovo 1 started operating. SPP Vrhovo 1 consists of 360 PV modules with a power of 215 W each, installed on the roof of the machine room of HPP Vrhovo.

The installed capacity of the solar generator is 77.4 kW, and the anticipated annual production is approximately 74.6 MWh of electrical energy. SPP Vrhovo 2 consists of 1584 PV modules with a power of 224 W each, installed on the right-bank dam of the reservoir of HPP Vrhovo.

The installed capacity of the solar generator is 355 kW, and the anticipated annual production is approximately 404 MWh of electrical energy.

2010:
SPP Vrhovo 2 started operating

mHE_Mavcice

1987:
Small HPP Mavčiče starts operating. It is located on the southern side of the Sava River, at the water inflow into the fish spawning ground.

The small power plant is equipped with a single unit that operates in parallel with the grid, supplying all available energy based on the prescribed constant water inflow of 0.5 m³/s.

In the powerhouse building of the small hydroelectric power plant, there is a unit comprising a horizontal spiral Francis turbine directly connected to an asynchronous generator via an elastic coupling. The turbine guide vanes consist of movable control blades surrounding the runner and regulating the flow. The adjustment of the blade opening is done manually according to the required flow. The runner is cast from aluminum bronze and is directly fitted and cantilever-mounted on the turbine shaft, which is supported by two roller bearings attached to the turbine cover. An asynchronous standard motor is used for the generator.

vrhovo

2008:
Small HPP VRHOVO started operating. It is located on the southern side of the Sava River at the water inflow into a fish spawning ground.

The small power plant is equipped with a single unit that operates in parallel with the grid, supplying all available energy based on the prescribed constant water inflow of 0.5 m³/s.

The turbine is a vertical, non-regulated, pipe propeller design. The runner is a propeller of modern hydraulic shape with four fixed blades attached to the runner hub. The turbine shaft is supported between the guide bearing and the combined turbine bearing. The guide bearing is submerged in water and lubricated with water. The combined bearing is located in the generator’s support housing and consists of radial and axial roller bearings. Lubrication of this bearing is done with grease. Power transmission from the turbine to the generator is designed to use an elastic coupling. An asynchronous standard motor is used for the generator.

MHE Cerklje is one of the older hydropower facilities, with its beginnings reaching back to 1924. The plant harnesses the Reka stream and combines a modest flow with a pronounced head to deliver stable production from a small alpine watercourse.

MHE Rudno harnesses the Češnjica stream, also known by its older name Rudnica. It is a run-of-river derivation plant where a steel pressure pipeline conveys water to the powerhouse over a notable gross head, allowing efficient generation from a moderate flow. The plant was modernised in 2020.

MHE Lomščica is a storage-derivation power plant above the village of Lom near Tržič. Unlike most smaller run-of-river plants, it combines an intake, a storage reservoir, and a pressure pipeline that delivers water under a large head to the powerhouse. The result is reliable peak production from an otherwise modest watercourse.

MHE Mojstrana was built in 1990 on the Triglavska Bistrica river. It is designed as a run-of-river derivation plant, where a side intake, a supply channel, and a pressure pipeline lead water from the catchment area to the powerhouse with two units. The plant is a typical example of harnessing a high-alpine watercourse in a sensitive natural environment.

MHE Davča harnesses the energy potential of the Davča torrent. It was built as a smaller run-of-river derivation plant where, after intake, water travels along a pressure pipeline to a powerhouse with two units. The facility is a typical example of efficient use of a smaller mountain watercourse, with the head difference and thoughtful placement of technical structures playing an important role.

MHE Sorica was built in 1989 on the Selška Sora, also known as the Sorica creek. The plant harnesses a small flow over a substantial head and is an example of how even modest watercourses can be used efficiently with thoughtful technical design.

MHE Soteska developed gradually in two main phases. The first unit was built in 1979, and the second was added in 1998, upgrading and expanding the use of the Sava Bohinjka’s water potential. A distinctive feature is the split supply system, which directs water toward two powerhouses, giving the plant its characteristic technical layout.

HE Savica is among the most recognisable hydropower facilities in our portfolio. It was built between 1948 and 1949 and harnesses water below the Savica waterfall, where natural conditions allow an exceptionally large head. Owing to its location in an extremely sensitive natural environment, the plant is an important example of combining electricity production with the protection of alpine natural values.

MHE Škofja Loka was built between 1919 and 1921 and belongs to the older hydropower facilities on the Selška Sora. Two turbines of different power allow effective use of the available flow under varying hydrological conditions. The long operating history attests to the plant’s solid technical design and its role in the local energy heritage.

MHE Standard is a modern hydropower facility on the Kokra, built in 2024, while the location has a long history of hydropower use. The plant uses a short intake channel and a contemporary technical design to harness a modest head and steady flow.

HE Sava in Kranj represents a modern use of the Sava river’s hydropower potential in an area with a long tradition of water-energy use. The facility has been thoroughly upgraded technically in recent years, with a new design of the intake structure, supply channel, and supporting infrastructure. Today’s plant combines the experience of older hydroelectric arrangements with new technical solutions for reliable and efficient electricity production.

MHE Zvirče, also known by its older name MHE Markelj, was built in 2002 on the Tržiška Bistrica. It is a low-pressure run-of-river plant that uses an existing weir as the intake and conveys water to the powerhouse through a combined concrete and steel pipeline. Two units of equal power deliver stable production from the Bistrica’s variable flow regime.

MHE Kokra is our oldest facility, having been built as early as 1898. Located on the Kokra river in Kranj, it represents an early example of harnessing water power in the wider Gorenjska region. The plant has been gradually modernised while preserving its historic character, and it continues to deliver reliable production from a small but steady head.

MHE Kranjska Gora was built in 1915 and is closely tied to the long history of water-energy use along the Pišnica river. The plant relies on a robust hydraulic system designed to handle floating debris and variable hydrological conditions, and it continues to be a recognisable part of the local landscape and energy heritage.