No. 11 (182) September 2010

HYDROPOWER IN LIGHT OF FUTURE CHALLENGES (HYDRO 2010)

Lisbon, Portugal, 26-29 September 2010

Yearly conferences "Hydro & Dams" usually gather a lot of participants. Recent conference in Lisbon was not exceptional - it gathered to exhibition and 24 sessions more than 200 persons under slogan "Meeting demands for a changing world".

The key report of Jone Brisko, former chief specialist on water resources in the World Bank, was alert - the international financial institutes returned to financing large waterworks as sources for solution of the sustainable development problems. Energy and Water - two very needed vital compositions. But what they look like?

Today more than 75% of world commercial energy is being produced at the heat stations (coal, gas, oil, nuclear fuel). This kind of fuel is supposed to be enough no more than for 200-300 years. At the same time the energy production per capita increases though sharply different: European countries and Japan - from 5000 to 10000 kilowatt/hours, USA – 14000 kilowatt/hours, Norway – 26000 kilowatt/hours, China – 1800 kilowatt/hours, India – 700 kilowatt/hours. It is naturally that India with its growth rate will aim to overtake China and then also the developed countries. The global hydro-energy resources are 2800000 megawatt. Recently the defined power capacity is 900000 megawatt or 32% (Sharma Hari, 4.02). (the indicated number in brackets is a reference number to the report's index at the conference, here and after)

Reporter openly denounced the nearly 25 years' policy of the Bank (from 1980 to 2003), when under the influence of a "very green movement" as a struggle against the Sardar Sarvak dams in India, as well as the Report of the Commission on Large Dams, investments into water infrastructure have fallen to 2000 in 2,5 times, into irrigated agriculture - from 20% in 1975 to 3% in 2000. The opposition of countries which are "self-sufficient in energy and food" to the needs "of hungry and destitute countries" had been overcome only gradually under the influence of pressure of transition countries (China, Brazil, India), who develop this infrastructure independently. It was competition that turned "the World Bank's camel" to finance these objects. But it is not correct to say that the return to old way has been occured. The priority in the hydropower development was given to developing measures on risk decreasing and systemic operation of the hydropower complexes.

Today a great attention is given to development of strategy on operation, policy and procedures in the hydropower sector.

EDP -"Energy of Portugal"- has developed a special guidance on preparation of such strategy. It includes:

• gathering, processing, analysing in detail of current operational characteristics in real-time mode;
• assessment of flexibility and multi-purpose capabilities of operational teams supported with effective and elaborated instruction on maintenance of objects;
• development and enhancement of vibration monitoring and analytical system to assess the infrastructure elements.

The main indicators that have been analyzed for 15 years (Paulo Costas Silva) (20.01):

• Total opportunity;
• planned interruptions in development;
• unforeseen outages.

A somewhat different approach in that direction was provided on the basis of experience of the German network of hydropower (BEW). The task was to standardize the operational strategy of two hydroelectric power stations, one of which was reconstructed, and the second one - was to be reconstructed. The purpose of the strategy was to identify in what areas the changing of the modern management system to improve efficiency and reduce potential risks is needed. The following has been analyzed:

• a detailed procedure to detect abnormalities in normal operation;
• the involvement of responsible experts into elaboration of recommendations;
• system analysis and standardization of procedures for HES's comparable sites;
• development of numerical performance indicators to make more transparent all the costs.

The above costs were reduced by 28% and the risk is reduced by 18% on average. The procedure was developed by Dr. Kalaitris Partner GmbH (20.04).

Norwegian experts (DHV) have analyzed the security risks of hydroelectric power plants operation in Western Europe and in Asia. It was defined that the fatal risk in Europe is 10-20 times less than the same in Asia. It was suggested a technique which can significantly reduce the risk in hydropower performance in developing countries (20.05). Overview of dynamic parameters and factors of instability and their influence on the state of hydraulic machines is implemented by the Swiss and Canadian professionals (20.07). Unintended the flow pulsing level, hydraulic shock, vibration flows during the operation of turbines, generators and pumps, affect all kinds of equipment, cameras and even buildings. The current operation imposes greater demands to changing the modes, reinforcing unusual phenomenon. Generalization of the most important cases and regularities on the basis of past and current researches is presented in the form of recommendations published in cooperation with the Canadian "Electrical Association" (CEATI International) and "Andriz Hydro", Switzerland. Various emerging hydraulic phenomena of instability, causing vibration, is structured in a practical manner with assessment of their impact, frequency of occurrence, troubleshooting. The measures are also given to reduce the risk of such phenomena in the HPS performance. The limits of international standards are specified. 22.05 - SH management and role (a review by the University of Cambridge).

Portuguese Hydropower Production (EDP) (22.06) didn't develop a big plans since 1992, having concentrated attention on increasing their efficiency and consideration of risk. However, in 2010 the Government decided to resume construction of hydropower stations and the construction of reservoirs to reduce the impact of climate change and the need of the long-term flow regulation strengthening. However, the inability to work in this area by the old methods has led to significant changes of approaches, design and construction of such structures. The main attention is focused on sustainable development, communication systems, information and involvement of local stakeholders, as well as a wide range of local official agencies, environmentalists, etc.

Evaluation of all surrounding area, which will be affected such new construction, is accompanied by prediction of income changes and assessment of damages for various participants. The full involvement of all local stakeholders, their information, their views and suggestions can help conflict-free start-up into operation, especially if compensatory measures are sufficiently designed and implemented . The involvement of specialists, economists and social mobilizers is essential element of such development.

Similar work is being implemented by Norwegian companies at their country and in Vietnam (22/07). The relationship between community leaders and the affected persons, land ownership, access to resources in the past and in the future, social inequality and the possibility of its reduction (or increase), possible assistance to the most poor population, economic opportunities, etc. is taken into consideration.

Increasing of problems in the hydropower and reservoirs' nodes operatin is connected with reservoir's sedimentation. Implementation of observing sediments, their dislocation, their sources is very important to estimate the life-time of reservoirs (24.01). IHE-UNESCO Institute (P. Boerliu, D. Roelviuk) has developed mathematical models of sedimentation process in large reservoirs (24.02). The methods of combat sedimentation were shown:

• France's experience at the dam Rizanesse in Corsica on application of the transit gate (24.04);
• special regimes of releases from reservoirs Murrow in Sudan for discharge of sediment downstream through the spillway (24.05);
• applying hydrocyclones for sediment discharge in Australia (24.06);
• washing tanks by using the largest settling ponds;
• experience of Nasna Dzhakri Project (7.24) and the Baspa project Phase II HE (24.09).

The report on investigation and measures on removal of the effects of the Sayan-Shushenskaya disaster of Dr. Berlinder, Director of the Institute VNIIG, has attracted exceptionally high interest. Commission of Accident Inquiry, having considered four reasons, has concluded that the accident occurred as a result of 6 screws disruption securing the 2-th hydrostructure that caused the explosion of the generator and turbine, flooding of engine room during 30 seconds, stopping electricity generation. All 75 people who were in the engine room died. Normal wear of all the bolts on the damaged turbines was 64.9%. Construction part is not affected. Discharge passed through the dam at the maximum of 9,400 m3 / s, reached 2350 m3/sec.

Currently 4 units have been repaired and are partially put into operation. 3 units are being repaired and 3 units will be produced. It is noteworthy that this is one of the highest dam in the world which in difficult climatic and hydraulic conditions has sustained emergency very well. Nevertheless, the lessons from this tragic history has to be learned:

1. The permanent control of operational status of all units, machinery, devices must be obligatory in such large water systems, as well as the creation of conditions of life-support equipment during the switch-off time (or during the accident on the power system). Power backup of such waterworks, regardless of the initial state, is necessary. Especially it is important for crane equipment when independent diesel units should be provided in the event of liquidation of all lines. Backup is generally a condition for the safety of such structures.
2. Verification of equipment's state should be done by operators together with equipment manufacturers at least 1 times a year.
3. All the "Rules of operation of large hydropower on rivers", including the" Rules of operation of large pumping stations" should be revised with consideration of analysis of the accident.
4. In a complex set of interactions between water management and owners of hydroelectric power stations and the systemic controlling energy flows and supply, the priority should be given to the water authorities who have to check the reliability of operation of all facilities and personnel readiness for emergencies on a quarterly basis. It is they who must approve the "Rules of operation of large water systems" and accurately monitor their implementation. Current incorrect commands of system operators out of line with those rules, should not be performed. From this point of view, the experience of Uzbekistan, which organized the special "State Committee of Supervision for large structures" under the Cabinet of Ministers of Uzbekistan is very good experience.

The Sayan-Shushenskaya HES's disaster must be the alarming case because the energy specialists can not be trusted to manage water. Water must be managed by water authorities and powermen has to use the water that can be allocated for them according to the river regime.

In general, noting the strong interest to the hydropower problems, the absolute underestimation of current situation, when hydropower is trying to dictate all their demands both on release regimes and economic approaches to all consumers should be emphasized. I raised this issue on the section "Multi-purpose use of water resources", led by Mr. Daryal Fields, a leading expert from the World Bank. Having been invited there as an expert, I noted that all reports were related to issues of national resources use, in which hydropower prevailed (the Chinese experience, the experience of Chile, a key paper of A. Biswas). Nevertheless, the integrated use of transboundary rivers has not yet a positive examples except the USA-Canada and India-Pakistan. Moreover, tensions are being pressurized more and more in water scarcity zones, where hydropower is trying to put their demands of upper watersheds as priorities.

Specific interest are presented the exploitation of off-channel reservoirs with units of bilateral operation (turbine-pump). In Portugal and Spain large complexes with capacity of 325-400 megawatts and low pressure (70 m) are built. These are Girabaltas and Alamera (800 m) in Portugal, and Mirales 2 (Voith Hydro) - in Spain. The use of "a wall in the ground" method is increasingly implemented in construction and repairing of dams. In 2006-2007 this method was used for repair of earthen core of Inguri hydroelectric power station in Georgia. Similarly, in Sri Lanka to eliminate leakage through the bottom and side filtering through the karst on the Samanolaveva dam which height is 105 m "a wall in the ground" with depth of 100 m and 1300 m in length was built. 13.400 tons of cement and 50,000 m3 of clay were used. Similarly, the concrete "a wall in the ground" has been used in Australia at the Hinze dam to reduce water losses, after a soil "wall" had not worked.

Prof. V.A. Dukhovny
Director, SIC ICWC