(NOMINATION FOR AUREA 2017 AWARD): Elektrovat - Implementation of best practices in construction of Beli kamen mini hydro power plant

In September 2016, the Belgrade-based company Elektrovat put the first of the three planned mini hydro power plants on the river Crni Rzav into operation. New water intake and transport technologies, so far not used in Serbia, have been implemented in the power plant.

The concept in question features COANDA water intake screens, which reduce as much as possible the biggest problems in water intake. Furthermore, it implements large diameter (1.8 m) PVC pipes made on the spot by spiral coiling, allowing for great savings to be made in transport.

The small hydro power plant Beli Kamen is a run-of-the-river power plant with 1.68 MW of power. It has been designed to operate without staff. In other words, remote management and supervision have been implemented and can be performed from any location featuring internet access.

The power plant has installed volume flow rate of 2.7 m3/s, and the annual capacity is 6.5 GWh.

Elektrovat has the status of a preferred producer of electricity. It is connected to the Elektroprivreda Srbije system at the 35 kV voltage level at the power plant gate, and has delivered 2,347 MWh to EPS since it was put into operation. The capacities will double with the construction of two new planned power plants, and the company's revenues would further increase.

The small hydro power plant Beli Kamen has been built and is operating at full projected capacity in line with all the environmental standards of developed countries (minimum flow rate, protection of flora and fauna, minimal negative environmental impact), and its construction has provided infrastructural pre-requirements for the construction of other small hydro power plants (around 9), the construction of which has been planned on the rivers Crni Rzav, Ribnica and Jablanica.

The total value of the investment amounted to EUR 5.2 million.

INNOVATION

(Photo: Shutterstock.com)

Beli Kamen is an example of the best practice in building small hydro power plants. Modern equipment by top-quality world producers has been installed in it and new water intake and transport technologies, so far unused in Serbia, have been implemented.

The first innovation is based on a new concept of water intake screens, of the COANDA type, which reduces as much as possible the biggest problems in water intake. It provides minimal watercourse power resistance, minimal waterflow disturbance and a considerably reduced need for construction materials (steel, concrete).

The innovation is based on the floating sediment theory. An equation determines the curvature of the sieve so that the entirety of the sediment from the water passes through it, with sediment over a millimeter in size not being able to pass through the sieve into the system. Each next rush of water washes the residue from the sieve, thanks to its inclination. The same solution is used in Sweden and Canada, there are a couple of sieves in Austria, and Elektrovat engineers have built the first such sieve in Serbia for the needs of this hydro power plant.

This:

– Fully eliminates the problem of trailing sedimentation;

– Eliminates the problem of sedimentation of leaves, floating objects, plastic objects, plastic bags and other items carried by the river;

– Prevents small water animals from entering the pipeline (the sieve only lets through particles under a millimeter in size), making for an “ecological” sieve;

– Allows for cleaning with minimal and intermittent interventions (except for algae, which need to be cleaned mechanically), making for a “self-cleaning” sieve;

– Makes for a self-defrosting sieve, which operates normally at temperatures up to 20 degrees below zero.

Another entirely new solution, at least in the Serbian context, was the one used in making spiral polyethylene pipes for transporting water to the water chamber and the pipeline under pressure. For the first time in Serbia, large-diameter (1.8 m) PVC pipes made on the spot using the spiral coiling technology, licensed by Vesbo, were used in raising a power plant.

Namely, the problem with pipes larger than 1,200 mm in diameter is transport. Since they are not produced in Serbia, they are transported from Turkey, and the transportation costs often exceed the value of the pipes themselves. For the first time in Serbia, Elektrovat implemented the construction of the pipes on the spot, in locations where they were to be mounted. The processed materials were delivered from Turkey and the 1,800 mm pipes were coiled at the construction site by rather simple machines, in various lengths, as per need, which reduced the costs considerably. At the same time, thanks to the size of the diameter, the pipes were enabled to accumulate water, an option used in the case of a low flow rate.

The small hydro power plant Beli Kamen is the first of the three planned power plants of Elektrovat on the Crni Rzav, and the construction of the remaining two is to begin following the completion of administrative procedures. The power plant has been designed and built to operate as part of a system of cascades with the next power plant, to be built downstream, as the pipeline goes from one power plant to the other without returning the water to the river. Beli Kamen on the Crni Rzav has two generators (featuring Francis turbines) of 1,220 and 470 kW, as well as a regulated total flow rate bypass towards the future downstream power plant, which can let through the identical amount of water for the next power plant in case one of the generators is malfunctioning.

The power plant premises are covered with 11 cameras. It has been designed to work without staff. One person is occasionally on standby, whereas the entire management, parameter setting, visual supervision of numerous important points within the intake system, water filtering and transport and visual control within and outside the facility are performed by remote control.

The small hydro power plant Beli Kamen has 1.68 MW of power. The installed volume flow rate is 2.7 m3/s, the head is 73 to 75 meters and the minimum flow rate is 140 l/s. The power plant features a very high degree of available hydro-potential usage effectiveness and is designed to operate for four decades before the first overhaul.

It is connected to the Elektroprivreda Srbije system at the 35 kV voltage level at the power plant gate. The transmission line is designed to meet the needs of all small power plants in the Crni Rzav basin. It is 11.6 km long and transports energy directly through TS Zlatibor 3 towards a higher voltage substation of 110 kV.

Beli Kamen is capable of producing 6.5 GWh of electricity a year, and the capacities will be doubled by the construction of two new mini hydro power plant.

SOCIAL USEFULNESS

(Photo: isak55/shutterstock.com)

The mini hydro power plant Beli Kamen was built entirely in line with the business plan and has shown practically all projected performances in the first 6 months.

All technological solutions proclaimed in the strategies for the usage of renewable sources of energy of the Republic of Serbia have been implemented and all environmental principles have been strictly adhered to – minimum flow rate, biological minimum, watercourse and coastal area protection from erosion and disturbance of the natural waterflow, protection of river flora (COANDA sieve), fish ladder, minimal, practically negligible damage done to the vegetation, minimal noise and absence of toxic waste, oil, petroleum and grease. A dry-type transformer has also been installed and the protection of the mineral water springs, in which the area's great potential lies, has been fully adhered to.

With this project, Elektrovat has given its contribution to increasing the share of renewable sources of energy in the final electricity consumption, bringing Serbia closer to reaching the set goal of 27% of RES in the gross final energy consumption by 2020.

The project has also led to the reconstruction and construction of 40 km of new forest and village roads, facilitating the fire protection of the area considerably, seeing how fires are frequent in the Zlatibor area, and enabling regular access to a large number of heretofore inaccessible parcels, pastures and forests.

The small hydro power plant Beli Kamen is the first in line of several small hydro power plants (around 9) planned by legal acts to be constructed on the rivers Crni Rzav, Ribnica and Jablanica. The construction of this power plant practically enables the construction of all other power plants, since the infrastructural pre-requirements for other small hydro power plants have for the most part been created (35 kV connection, optical cable, access roads...).

The projects has been accepted and supported by the local populace and local communities of Donja Jablanica and Semegnjevo, as well as the local self-government of Cajetina as a project of special significance. Local populace was employed during the construction of the power plant for various purposes, and people from the direct surroundings were hired for basic maintenance, physical supervision and as security at the hydro power plant.

FINANCIAL POTENTIAL

(Photo: Syda Productions/shutterstock.com)

By implementing innovative technology of world producers, Elektrovat proclaimed as its primary goal a permanent increase in the ability to stand out from the competition and be one of the best in its field.

The small hydro power plant Beli Kamen was put into operation in September 2016 ( the construction took around 14 months, after all the necessary permits were acquired), and the company has had the status of a preferred producer and had an agreement signed with EPS on the production and distribution of electricity since.

The annual production capacity is 6.5 GWh and the electricity is sold at the price of 10.37 cents, bringing EUR 670,000 in annual revenues to the company. The power plant belongs to the group of medium-profitable small power plants and the construction of the two new planned mini hydro power plants, with the total capacity of 6,000 MWh, will double the capacities, considerably increasing the company's revenues.

A total of EUR 5.2 million was invested in the construction of Beli Kamen and it is expected that the investment will be returned in 10-12 years. The construction of another two small hydro power plants on the Crni Rzav will bring the total investment up to EUR 9 million.

Elektrovat has been operating since 1990, with core activities in electrical energy, automation and production process management. It has 80 employees, of which more than 30 engineers.

The company Zlatiborske Elektrane was founded for the purpose of construction and operation of the small hydro power plant Beli Kamen, and the Cacak-based company SNE Energy, a licensed partner of Schneider Electric for the production of medium voltage facilities and equipment under the company's brand, has been operating as Elektrovat's subsidiary since 2011.

If construction of mini hydro power plant Beli Kamen is your favorite one for the investment of the year, you can vote at the official Aurea award website.

Elektrovat d.o.o. Beograd

eKapija.com Beograd

Zlatiborske elektrane d.o.o. Čačak

Elektroprivreda Srbije ad Beograd

SNE Energy Čačak