Russian hydro revolution

In the first three quarters of 2013, Russian power generator RusHydro saw a 23% increase in hydroelectricity generation compared to 2012, with total hydropower production for the nine months amounting to 71.4TWh (+23%).

Much of the reason for this increase in generation was attributed to higher than average water inflows to major reservoirs in Siberia, which offset lower than average inflows into the Volga-Kama cascade. There was also a substitution of thermal generation for hydro in the Far East. Going into next year, this figure looks set to increase with higher inflows expected, as well as the continued rollout of a comprehensive modernization programme of RusHydro's generation fleet.

Modernization

Beginning in 2012 and lasting to 2025, the RusHydro modernization programme provides for replacement of 55% of turbines, 42% of generators, and 61% of transformers. This modernization will result in significant reliability, efficiency and security improvement of RusHydro generating facilities, and an increase in installed capacity of 779MW as compared to the beginning of 2011.

Among the projects being refurbished is the Zhigulevskaya hydropower plant, which will see each unit at the plant have its capacity increased from 115MW to 125.5MW. In late 2013, unit no 19 was placed into operation - the third unit to be launched. Upon completion, installed capacity at the project will be 2488MW, up by 147MW.

Also launched late last year was a new 640MW unit at the Sayano-Shushenskaya hydropower plant, the third to be commissioned at the project in 2013, and the seventh overall to be put into commercial operation as part of the rehabilitation and comprehensive modernization of the project. Currently, the working capacity of the 6400MW plant is 4480MW with the seven units in operation. The restoration of units No. 3 and 4 continues and is scheduled for completion in March and June 2014 respectively.

Upon completion at the end of 2014, the Sayano-Shushenskaya hydropower plant will be fully equipped with new up-to-date equipment with enhanced performance characteristics that meet all safety and reliability requirements. The useful life of the new units has been extended to 40 years and maximum efficiency now reaches 96.6%. They also have improved energy and cavitation features. The turbines will be fitted with a more efficient process protection system, which will automatically shut down the unit in case of any inadmissible deviations from controlled parameters.

Yegorkykskaya hydro project

A further project scheduled for completion in 2014 is the construction of a new spillway of the Yegorkykskaya hydroelectric power plant.

Part of the rehabilitation and modernization of the cascade of hydropower plants on the river Kuban, construction of the spillway began in 2013, and upon completion it will be used for water discharges and to replace the existing 50 year-old spillway which has a lower capacity.

The new spillway;s capacity will be 120m3/sec, allowing full water passage even in case of full outage of the turbines. Combined pass-through capacity of the hydropower plant will total 250m3/sec, sufficient to withstand even extreme floods.

The spillway will be built of monolithic concrete, and will be 517m long and 17.6m wide.

The Yegorlykskaya station, built in 1956-1962, comprises a 1320m long landfill dam, intake canal, tower spillway, discharge canal of the spillway and turbine building housing two hydropower units with combined capacity of 30MW.

The rehabilitation and modernization of the cascade of Kubanskiye plants is being implemented by RusHydro and Alstom Hydro under an agreement signed in 2011. The project covers comprehensive modernization of eight hydropower plants and one pumped-storage plant. One of the nine plants of the cascade - the Yegorlykskaya HPP-2 - is not included in the project as it is newly built and was commissioned in 2011. Alstom will manufacture equipment and will supervise installation and pre-launch testing for the projects. The key component is introduction of automated centralized control of the cascade from the town of Nevinnomyssk.

Boguchanskaya project

This year looks set to see full completion of the Boguchanskaya hydropower plant. Construction of the stalled project resumed in May 2006 after RusHydro and UC Rusal signed an agreement on the joint development of the Boguchanskoye Energy and Metals Complex (BEMO), comprising the Boguchanskaya hydropower plant with average multi-year generation of 17.6GWh and aluminum smelter with capacity of 600 tons of metals per annum.

The eighth unit was commissioned and put into commercial operation at the end of 2013. Total installed capacity of all units in operation by end of December was 1998MW, working capacity accounting for lower reservoir level is 1362MW.

Preparation of the last unit for testing is currently underway.

Nizhne-Bureyskaya project

Scheduled for commissioning over the next couple of years is the Nizhne-Bureyskaya hydroelectric plant, a compensating reservoir of the Bureyskaya plant and the second plant of the Bureyskiy hydropower complex. The design capacity of the project is 320MW, with average annual output of 1650MkWh. In addition to power generation, another important function of the plant will involve levelling uneven daily discharges from Bureyskaya plant and preventing flooding. Nizhne-Bureyskaya has been under construction since 2010 and is one of the priority projects of RusHydro JSC Investment Program.

RusHydro subsidiary Nizhne-Bureyskaya HPP OJSC recently awarded Power Machines a contract to supply four hydropower units each having a capacity of 80MW for the project.

Under the terms of the deal, Power Machines is to design, manufacture and supply four sets of hydropower units each comprising a Kaplan turbine complete with an automated control system, a hydrogenerator with excitation system as well as auxiliary equipment. The company will also install the units at the hydropower plant.

The plant's hydro turbines have been designed with an environmentally-friendly design: the impeller cavity where the blade turning mechanism is located will not be filled with oil which excludes the possibility of oil leakage into the water.
Commissioning of the units is scheduled for 2015 to 2016.

Cheboksarskaya

Power Machines was also involved in the project to renovate the Cheboksarskaya hydroelectric project. November last year marked completion of the overhaul of the impeller of hydropower unit #15.

Thanks to this renovation the impeller blade turning angle will vary depending on the load and head pressure, allowing for maximum electric power output at minimum water consumption.

The renovated hydropower unit is scheduled to be put into operation early this year upon completion of the entire scope of construction and mounting works and following commissioning tests.

The hydropower units overhaul at Cheboksarskaya began in 2007 with the renovation of the blade turning mechanism of impeller number 7. Three more impellers - those of hydropower units 16, 8 and 4 - were overhauled betwee 2010 - 2012. At present the Kaplan operation mode of the plant's unit number 6 is being reestablished at the manufacturing plant. Five more turbines will have been renovated by the end of 2016.

Having entered into a contract to overhaul eight hydropower units in October 2012, Power Machines and RusHydro expanded their cooperation aimed at the renovation of Cheboksarskaya hydropower units.

Eight sets of stators with necessary equipment are to be manufactured to complete the hydrogenerators. Delivery of the first of the eight sets of equipment is scheduled for January 2014 with the last in February 2017.

New joint venture company: VolgaHydro

Another company working with RusHydro is Voith Hydro. In 2013, the companies announced plans to establish a joint venture company, VolgaHydro LLC, in which RusHydro will hold 50% plus RUR 1 share, with Voith Hydro holding 50% minus RUR 1.

The JV will manufacture hydroturbine equipment, with the aim of becoming a center for innovation.

Headquartered in the city of Balakovo in the Russian Federation, the joint venture will look to work on both new and modernization projects.

Zagorskaya pumped storage plant accident

It wasn't all good news for Rushydro in 2013.

On 17 September, water seepage was noticed in the turbine room at the Zagorskaya pumped storage plant No. 2 which is currently under construction. There were 15 people working inside the powerhouse at the time, and all of them managed to leave the building.

During the subsequent several hours, the turbine room and the adjacent territory flooded. Inspection has revealed that the plant building has subsided. The flooding of the powerhouse took place via broken expansion joints and intakes of unfinished water pipes. The follow-up research, including drilling wells in the vicinity of the right-wing part of the plant building, has identified erosion of soil. This soil erosion has caused the building to sag.

According to preliminary data the erosion of the foundation soil of the Zagorskaya plant was caused by inefficient performance of the impervious system of the plant. Insufficient efficiency of the system is explained by particularities of the system design and insufficient exploration of the foundation soil. The final conclusion on the causes of the accident will only be available when additional surveys of the powerhouse are carried out when it is fully dry.

Weak foundation soil and insufficient measurement instrumentation provided by the design of the plant didn't allow the potential problem to be identified, RusHydro said in a statement.

Immediately after the accident, restoration operations began. On the side of the tailrace an earthfill link was built in late September, early October, isolating the plant building from the lower reservoir and allowing gradual pumping of water to begin. Examination of the equipment will be completed after the power house building is fully dry, which is expected in mid February.

The conditions of hydrotechnical facilities have been stabilized. The next step will include measures aimed at restoring the powerhouse to the proper position, after which fine-tuning of equipment will begin in order to prepare the plant for commissioning.