Past event - HYDRO 2008
Progressing world hydropower development
About 800 participants from more than 70 countries gathered in Ljubljana, Slovenia, for HYDRO 2008. A broad range of subjects were covered, and as usual much emphasis was placed on issues relating to hydropower potential and prospects in the developing countries. A special session was devoted to capacity building needs, and another focused on the challenges involved in progressing the Bujagali project in Uganda to financial closure. Session Chairmen have prepared the following brief overviews and outcomes of the 21 sessions.
After a welcome to HYDRO 2008 by Alison Bartle of Aqua-Media, Prof Luis Berga, President of ICOLD, gave an opening address on behalf of ICOLD, one of the main supporting organizations. He referred to the benefits to society of dams, noting that one of the most important functions was hydropower; the 44 largest reservoirs (representing > 25 km3 of storage) having hydro as one of the main functions. He referred to the fact that 1.6 billion people in the world had no electricity supply, and said that unless vigorous news policies were implemented, estimates indicated that around 1.4 billion would still lack a reliable electricity supply by 2030. He recalled the Millennium Development Goals, and the key role which water and energy schemes could play in meeting these goals.The Conference was declared open by Slovenia's Minister of Economy, Mr Andrej Vizjak.
Session 1: Global needs, potential and development opportunities
The first session was chaired by C.V.J. Varma, Chairman of the Council of Power Utilities, India, and Hon. President of ICOLD.
Adama Nombre, Past Vice President of ICOLD analysed the root causes of increasing unrest round the world, linking them to food security, and to the need for increased water resources development. The increasing cost of essential food items, he felt, was of great concern for the survival of humanity. He then moved on to water and energy needs, and plans for the future. An article based on his lecture is published in this issue (p47).J. Kelman, Director of Brazil's national regulatory authority, ANEEL, described the important role of hydropower in his country. He began by outlining the latest situation in the Brazilian energy sector, and gave details of per capita consumption of electricity. He presented the country's energy matrix, demonstrating that renewable energy sources accounted for 89 per cent, with hydraulic energy representing 85.4 per cent.
Important aspects at present, he said, were:
valuation of the multiple implications of projects; definition of better use of hydro potential within river basins; and, interaction with planning in other sectors.
He then described some of the very large hydro projects going ahead and planned in Brazil, which he described as the 'new hydropower frontier'. He outlined details of the first two projects in the Rio Madeira complex (San Antônio and Jirau), now under way, and also plans for Belo Monte on the Xingó river, which is due to go ahead in 2009, and which could have an installed capacity of 11,181 MW.
A.K. Mishra, General Manager of NHPC in India, began his talk by describing the current status of the Indian power sector. He then moved on to opportunities for hydropower development in his country. Hydro currently contributes 25 per cent of India's electricity, with a capacity of 36,158 MW. He gave details of the enormous remaining hydro potential, by region, which totaled 112 542 MW.
He then outlined some of the key government initiatives implemented to accelerate future hydro development, which include the 50,000 hydro initiative. As a result of this, he said, prefeasibility reports had been prepared for 162 hydro projects in 16 States, totalling about 47,000 MW.
A presentation by F. Lempérière, of Hydro Coop, France, gave a very comprehensive analysis of the present and future energy needs, and demonstrated the major role which large tidal storage basins could play in the future. He noted that world electricity needs could be multiplied by a factor of five during this century, making such systems extremely valuable. An article based on this paper appeared in H&D Issue 1, 2008.
Session 2: Social issues and stakeholder involvement
This session was chaired by Dr Stephen Sparkes of Norplan/Theun Hinboun Power Company, Laos.
He commented that the fact social issues were presented in Session 2 of the Hydro 2008 Conference was evidence of the central role of social planning and mitigation in the hydropower industry. This resulted partly from the criticism of the handling of social issues, he felt, in particular resettlement and livelihood restoration, culminating in the World Commission on Dams Report (2000), and in part to the growing demands for successful social mitigation and acceptance by affected communities.
The papers presented in this session, Sparkes said, emphasized the challenges and strategies at present being employed by projects to meet these increased demands on planners and implementation teams, and the complex interaction between hydropower projects and local communities.
Participation of local communities on the Madeira river, a tributary of the Amazon, near the city of Porto Velho in Brazil, centred on achieving the smallest possible environmental impact (M. A. Porto and A. A Goulart Neto of Furnas Centrais Elétricas S/A). More than 60 consultation meetings had been held in various communities. These meetings focused on how to improve the quality of life and community priorities. One aspect described was the expectation of employment during construction, and how the developers had undertaken an extensive training programme for 18 000 workers in the light of existing low levels of formal education in the region, contributing to acceptance and long-term benefits for skilled workers during the construction and in terms of providing economic stimulus for the future development of these communities.
Prapard Pan-Aram of EGAT, Thailand, presented a paper on the challenges of achieving public acceptance for the Pak Mun dam in northeast Thailand. This example had involved an innovative approach for finding solutions, which had involved groups with opposed views and concerns: the various water users had included fishermen reliant on fish migration along the river blocked by the dam, ample water for irrigation systems (beneficiaries of the project) and water for power generation. The result was power generation that allowed for fish migration during high flows, maintaining high enough water levels for irrigation systems; this satisfied all groups to some extent, and had still resulted in a viable project. A number of hydropower projects in Lao PDR have involved extensive consultations with local communities to ensure that benefits reach affected people in terms of resettlement planning and long-term livelihood restoration.
Chairman Dr Stephen Sparkes presented three case studies which illustrated the challenges of achieving acceptance by communities regarding the choice of resettlement sites, food security and agricultural development. The establishment of trust and cooperation could take a long time, he said, and involved patience and adaptability, as well as a willingness to take opportunities as they evolved and to anticipate change. The ability of a social implementation programme to adapt to circumstances, to understand people's perceptions of their own risks and morality, and to seek new solutions within a mitigation framework were key aspects, he said. A participatory approach was an open-ended one, which evolved, and differed from a planned engineering solution with its causative and linear reasoning. There were a number of other papers not presented in the session for various reasons, but papers had been published.
These included an example of acceptance through the introduction of multipurpose aspects (spatial planning, flood control and recreation development) of the Sava river hydropower project in Slovenia; the Gurara water transfer project in Nigeria with community involvement and bottom-up planning (published in this issue); and the involvement of multi-stakeholder dialogue for the Akosombo dam on the Volta river in Ghana. The latter sets the stage for the new Bui dam construction. These papers highlighted the need for participatory approaches, which, it was agreed, although sometimes complex, couyld lead to a hydropower project which was a 'social success'.
Session 3: Hydrology and climate change
This session was chaired by Prof Luis Berga of Spain, President of ICOLD. It covered general aspects of hydrology and flood forecasting, as well as the implications of climate change on the design and operation of water infrastructure.
In his own address, Prof Berga discussed the role of dams in adapting to climate change, saying that problems would be accentuated by climate change, with increasing impacts and pressures on water and energy resources.
He reviewed current research which had indicated rises in temperature and sea level during the last century.
Berga pointed out that some 8300 km3 of the earth's water was impounded in storage reservoirs, and this would lessen the decrease in the global sea level by some 15 per cent.Flooding in the 20th century had increased significantly, he continued, as a result of a progressive increase in the vulnerability of flood-prone areas, and also the more widespread occupation of flood plains.
In the water sector, Berga said, climate change adaptation strategies ranged from water storage to more intensive rainwater harvesting, conservation measures and water re-use, improving irrigation efficiency and desalination. He stressed that the concept of integrated water resources management was critical, and concluded that investments in climate change adaptation should incorporate water storage as a top priority. He added that developed countries would have significant adaptive capacity (for example, water storage and IWRM). Developing countries, however, generally lacked sufficient water storage infrastructure, as well as financial and institutional means, and access to the public services which could help them adapt.
The role of dams in flood mitigation would assume more and more importance in the future. O.G.B. Sveinsson and co-authors, from Landsvirkjun, Iceland felt that risk analysis relating to climate change should be explored and extensively used. This paper pointed out that the profitability of hydro systems could be enhanced, but usually only by the acceptance of greater risk. Specific impacts which could relate to hydro generation in Iceland, Sveinsson said, were:
glacial runoff being expected to double over the next 40-60 years;
the possibility that glaciers could disappear over the next 200 years;
the need for better utilization of existing capacity; and,
for future hydro projects, decisions on installed capacity and reservoir storage needing to be based on expected climate change.
Dr Fiona Ling of Hydro Tasmania also contributed to the presentations on climate change. She explained that Tasmania had valuable water resources, but that rainfall was distributed very unevenly in both space and time. Hydro Tasmania had carried out a climate change study in response to perceived business risk. The focus had been on possible impacts in Hydro Tasmania's catchment areas, and the study had examined trends in rainfall, temperature, evaporation and wind. Outcomes were incorporated on various models to assess the possible impact on businesses.
Chawalit Kankham of EGAT, Thailand, described an automatic water management alert system in use in his country, and A. Vidmar of the University of Ljubljana, Slovenia, discussed a flow forecasting system in use in relation to hydro plants on the Sava river; it could forecast low flows seven days ahead.
Session 4: Asset management and optimizing operation
Chairman G. Wedam reports that there were seven excellent presentations, by speakers representing seven different countries (USA, Slovenia, Poland, France, Austria, Australia, Portugal and China).
Lessons to be drawn from the discussions during the session, he felt, were as follows:
To correspond to market requirements, advanced system optimization is indispensable.
To receive green certificates for a pumped-storage plant with natural inflow, accurate measurement of turbine and pump discharges is required.
The coordinated and optimized operation of a cascade of multipurpose run-of-river plants (such as those on the Rhone) is a very challenging task.
The sustainability of hydropower plants depends very much on their technical condition, and on the methods of advanced condition monitoring.
Hydro assets should not be subject to 'business dollar priority' when it comes to maintenance and asset preservation.
The importance of hydropower data processing as a decision-making instrument should never be underestimated.
Construction of an RCC dam can be considered as an economic solution; however, it requires a high degree of logistic skill to allocate the right resources during construction. An impressive simulation from the Three Gorges University was presented.
Session 5: Hydraulic Machinery
Chairman J.H. Gummer of Hydro Consult Pty, Australia, summarized his session as follows:
The opening paper, presented by D.V. Bannikov of the Institute of Computational Technologies, Russia, covered the optimization methods for turbine runner design used by the Institute to maximize efficiency and minimize cavitation erosion. Algorithms are used to fine-tune the hydraulic design, thus giving the optimum profile to fit the project requirements. In answer to a query from the floor, the presenter explained that the various design parameters to be optimized had been given by turbine designers such as LMZ who co-authored the paper.
The shaft line system of a hydraulic unit is a critical component, which has to deliver the output of the unit from the prime mover (turbine) to the generator successfully, within the critical speed restrictions of the bearing arrangement. As such, the bolted connections of the flanges of the individual shafts must be convenient to make and provide the necessary facilities to transmit the torque across the flange. F. Rayman of P&S Tensioning Systems described a novel design of bolt which uses an expansion sleeve instead of a fitted bolt. The sleeve is expanded inside the bolt hole with a tapered sleeve, the end result giving a far better distribution of stresses in the bolt hole than afforded by a fitted bolt, as was evident in the Finite Element calculations presented.
D. Dolene of Litostroj explained his company's recent development of a computerized governor simulator. The various components of the hydraulic and electrical system were represented in the simulator by transfer functions which can easily be adjusted to accommodate the parameters of the project being analysed. The governor undergoing simulated testing was then connected to the computerized simulator and its performance under various operating conditions analysed.
Prof. H. Brekke gave a comprehensive summary of Norwegian hydro development over the past 75 years, covering subjects such as high-head turbines, improved regulation of turbines using penstock air chambers and the major improvements in performance which can be obtained in Francis turbine operation by using the 'X' blade or balanced profile design.The operation of electrical systems containing hydro units under fault conditions was discussed by G. Taljan of the University of Ljubljana, Slovenia. The system used is computer based, with transfer functions representing the various components in the system. The author gave a detailed account of the simulations devised for the Slovenian system, as predicted for the years 2010 and 2024.
With the increased amount of intermittent renewable energy in today's electrical system, the role of hydro, and particularly pumped-storage, in system regulation is becoming more and more important. J.M. Henry of Alstom gave a detailed account of his company's recent developments in pump-turbine technology, concentrating on the double-regulated two-stage unit at Yang Yang, Korea, the use of ring gates for turbine isolation and the various power station arrangements which can be used for pump-turbines and pure turbines, depending on the size head and function of the particular unit.
Trouble-free operation of the main inlet valve of a hydro unit is essential for the security of the unit. There are, however, a myriad of different operating methods for such valves, ranging from oil opening counterweight closed, to penstock water opening, to penstock water closed. A Cañellas of IMS SA, Spain, explained the advantages and disadvantages of the various systems, dealing with older techniques encountered in refurbishment work, as well as the more modern preferred systems.
With today's concerns regarding greenhouse gas emissions and global warming, energy from the sea is becoming more relevant, and of research interest to many bodies, including manufacturers. As explained by J. Weilepp of Voth Siemens Hydro Power Generation, his company has an active interest in the development of both wave and tidal stream technology. He described a working prototype of a land-based oscillating column device incorporating a Wells turbine, which is showing promising results. He also presented a conceptual design of the company's proposed tidal stream turbine, concentrating on the problems which must be overcome for effective maintenance of such a device. In response to a query from the floor concerning cost, Dr Weilepp explained that this was an emerging technology, and although current prototypes are uncompetitive compared with, say, on-shore wind, it was only a matter of time before the costs would reduce, as they had done historically for every other renewable development.
The hydro-mechanical equipment in the water conduit system of the 1000 Tehri project was comprehensively described by M.K. Jain of the Tehri Hydro Development Corporation Ltd, India. He gave details of the intake, spillway, penstocks, guard valves and draft tubes.
Session 6: Commercial aspects of hydropower development
This session was co-chaired by J-M Devernay of EDF, France, and Liz Bossley of CEAG, UK.As an introduction to the session, it was stressed that funding remains one of the main challenges which prevent many hydro projects from moving ahead, despite the current boom that hydropower development is enjoying in many parts of the world.
This is especially the case in countries which have no other choice but to rely on foreign investment and support from International Financing Institutions to develop their much needed hydro projects, which are often essential for the development of their economy as a whole.
In the first part of the session, the new funding opportunities linked to the contribution of hydropower in reducing CO2 emissions were discussed, and experience of carbon trading. Co-Chair Liz Bossley presented a clear overview of international emissions trading, including a resumé of the Kyoto Protocol, and an explanation of the concept of 'cap and trade schemes'. She explained that international negotiators were working hard to reach agreement on a successor to the Kyoto Protocol, to take effect from 2013. The so-called Bali roadmap, she said, requires a consensus on the post-2012 deal by the 15th COP to be held in Copenhagen in December 2015. An interim report is due at COP 14 in Poznan, Poland in December this year.
Two other papers were presented in this part of the session, both from North America. R.J. Carryer from Synexus Global, Canada, discussed hydro generation efficiency improvements which could qualify for carbon credits, and Bruno Trouille of MWH, USA, gave an overview of US experience on carbon trading.
The second part of the session identified a number of avenues on which further work is needed to ease the process of financing of hydro projects :
Reduce the risk level so that hydro projects become more attractive for private investors.
Look for optimum sharing of risks, rights and responsibilities between the public and private sectors.
Firm up the role of the International Financing Institutions.
Reduce project costs through a project structure which ensures that the design is cost effective, and that civil works and equipment are priced competitively.
Reduce construction time, so that interests during Construction are minimized and the project starts to generate revenues and reimburse the loans as early as possible.
Translate governments' political will into an enabling legal, fiscal and institutional framework.
Chris Head, of the UK consultancy firm, Chris Head Associates, identified key commercial issues in hydropower development connected with the fact that projects are, by necessity, site specific and involve a nationally owned asset, that is, water, developed by private sector firms. The privatization and unbundling of power into the hands of utilities has been restricted in the case of large-scale hydropower to private and public partnerships, for which there is no standardized model for commercial arrangements.
Speakers came up with ideas and concrete examples on how to make progress on solving those challenges in various contexts, starting with a better understanding of the respective expectations of the private sector and the public sector when partnering for developing a hydro project. The EIB's current policy and instruments were presented as an example of IFIs' involvement in the process.
Two innovative case studies were presented: the 280 MW Dhauliganga hydro project in India, stressing the importance of reducing the cost of debt and the gestation period; and, the Crna river cascade in FYR Macedonia, illustrating the benefits of a well designed public-private partnership.
The importance of political will and a regulatory framework was illustrated by the encouraging effects of the most recent European energy initiatives on the development of small hydro.
It was emphasized that demonstrating social and environmental performance, using, for instance, the IHA sustainability Guidelines and Protocol, was a key ingredient in attracting responsible investors and lenders.
Gema San Bruno, Deputy Secretary General of ESHA, presented an overview of the current status and perspectives of the SHP sector in the European Union, including the changing attitude to SHP stimulated by the new European Directive promoting RE. She felt that current and future economic and political events were attracting investors to the SHP sector.
Session 7: Hydro plant modelling and design
This session was chaired by Prof. Dr. Petru Boeriu of UNESCO-IHE, Delft, Netherlands.He noted that the topic of the session had been recognized as fundamental at several major international conferences on hydropower development. During the past 10 years, with the world at the brink of a crisis widely recognized as the energy crisis, and increased interest of the main stakeholders and financial media to support the development of clean energy, the topic of modelling and design of hydro plants had became even more prominent. Unsolved or partially solved design issues, as learned or identified in practice, are today studied and analysed based on the obvious progress in numerical methods and the increase in computational power. At the same time, the use of scale studies and field measurements had again proved to be of great importance in the calibration of models, the validation of the results and even the solution of problems, he said, which at present could not be resolved by numerical methods.
The main issues where speakers in the session offered valuable contributions were:
Application of numerical models and validation of the results by using scale studies to improve the design procedure for stilling basins and loading basins at small hydro plants, by an appropriate analysis of the physical phenomenon.New solutions established by using hydraulic model tests. Examples discussed related to: increasing the discharge capacity of existing spillways; establishing the optimum operation of all the newly built powerplants on the Sava river in Slovenia; and, an optimized solution for the design of the power intake for Plave II hydropower plant on the Soca river, Slovenia .
A contribution to the improvement of turbine laboratory test methods,
A numerical solution for the structural design of the pressure tunnels.
Maximization of energy production on the Ruzizi river at the border between Rwanda and DR Congo.
A number of important issues were identified by participants during the discussion on the papers presented. Some of the main points raised were as follows:
There are several areas of hydraulics where standardization is possible and appropriate.
However, as demonstrated by the results of a hydraulic study of the powerplants on the Sava, standardization is barely applicable in the design of the hydro plants structures. Each component of the layout should be carefully analysed and design should be based on local conditions.
It is widely recognized that great progress has been made in the application of numerical methods in solving practical design problems, but the importance of linking this to laboratory studies should not be overlooked.
Currently, modelling is increasingly present in the area of the applied hydraulic research, but the remarkable results obtained do not diminish the need for a good understanding of the fundamental physical concepts, and the need for careful verification and validation of results using scale studies or field measurements.
Finally, all the participants agreed that in the context of a world acknowledging more and more the need for using natural hydro resources, the topic of modelling and design of hydro plants should remain an important topic on the agenda of future international meetings of the water professionals.
Session 8: Recent developments in electrical engineering
The Chairman of this session was Prof. J-J. Simond, of Ecole Polytechnique Fédérale de Lausanne, Switzerland. He reported on the discussions as follows.
Nine papers had addressed the following important topics in this well attended session:
cooling flow for large hydro generators; insulation technologies; stator core-stator frame connection, AND stator core buckling; stator vibrations, and resonant bending frequencies;automatization of hydro powerplants; and, Black start strategy.
Hydro-Québec presented a methodology to study the air flow in large hydro generators, balancing both the complexity of the flow associated with its large length scale variation and requirements in terms of reliability and investment. This methodology uses a coupling between two simulations, one global and one detailed, relative to one stator slot. The first results appeared to be very promising; precise measurements on real generators should help to improve and to confirm this new methodology.
An Alstom paper described an improvement in the stress grading system. This improvement fulfilled the customer's requirements for blackout and corona tests. Various solutions in terms of materials and application processes had been compared, to guarantee the insulation resistance, the polarization index, the corona inception voltage and the bar performance during accelerated aging tests.
A Voith Siemens Hydro contribution concerned a methodology for the measurement of partial discharge, to control the quality of the electrical components of rotating machines. A collection of data in form of a PD database allowed the identification of relevant parameters for the evaluation of the manufacture quality. Mathematical fits had been used to determine a standard deviation, maximal PD levels, serving to evaluate the quality and the uniformity of the production.
VA TECH Hydro proposed a new thermo-mechanical decoupled stator design for high end bulb generators. The main innovation is a new connection between the stator core and frame in combination with a new reverse-flow cooling system. This new design allows for radial expansion of the stator caused by thermal effects. The new reverse-flow cooling system reduces the stator temperature substantially. The thermo-mechanical stresses in the stator core are therefore reduced to an acceptable level, and the durability and the reliability of the unit is improved.
Voith Siemens Hydro presented an investigation of generator stator core buckling and a design upgrade using advanced FEA methods. A coupled three dimensional FEA model of the assembled stator core, clamping system and frame had proved to be a very valuable tool in the root cause engineering investigations and in the upgrade design engineering study. This study also showed that the company's standard analytical tool for the review of out-of-plane buckling of stator cores was in very close agreement with more detailed FEA analysis.
Another VA TECH Hydro paper dealt with the simulation and measurement of the vibration of hydro generator stators. Two tools for the calculation of stator vibration were presented: a simplified 2D-model of a small portion of the stator, including slots and wedges, and a detailed 3D model, including the stator core and the stator frame. A comparison with measured results showed that both models were able to predict natural frequencies in quite AN accurate way. Litostroj described a testing procedure consisting of a mechanical actuator exciting the system and measuring the response of the latter. This method will contribute to a better understanding of critical speed and consequently to improving the optimization of hydropower unit operation.
VA TECH Hydro also presented a paper entitled 'Operation research methods in the automation of hydropower plants'. The hierarchical structure of the energy automation of a production company was well presented. The case of joint operation of a powerplant cascade had been specially analysed.
EDP of Portugal described the implementation of a black-start in the special case of a total breakdown in the Portuguese grid, characterized by an antenna grid topology.
Session 9: Hydraulic machinery - R&D
Session 9 was chaired by V. Kercan, and covered research and development in the field of hydraulic machinery. Experience from Russia, Canada and several European countries was discussed. Topics included the use of CFD for a study on replacing a Francis unit with a modern Kaplan machine; research on cavitation characteristics in high-head pump-turbines; optimizing the efficiency of Francis runners; instability of reversible pump-turbines during startup in the turbine mode; and. the influence of Kaplan runner blade thickness on its stress parameters.
Session 10: Achieving financial closure at Bujagali, Uganda (Debate)
One full afternoon was devoted to a series of presentations on the 250 MW Bujagali hydro scheme, which is currently the largest private hydro scheme in Africa to reach financial closure. Located on the Victoria Nile, below what was previously known as the Owen Falls hydro station, the project is currently under construction, after a long and difficult gestation period, which has lasted for more than ten years and seen the withdrawal of one sponsor.The session was chaired by Chris Head of the UK, and co-chaired by Sandy Tickodri-Togboa, Chairman of the Uganda Electricity Generation Company. Presentations focusing on the financing aspects were made by representative of the Developer (Glenn Gaydar of Sithe Global, USA), the Electricity Regulator (Johnson Kwesigabo) and one of the main financiers, the European Investment Bank (Marcel Gounot). Following this, there were questions from the floor and a lively discussion.
The general conclusions were:
The project had suffered serious delays at the outset because of concerns over a lack of transparency in the procurement process, and as a result of a vigorous campaign by NGOs who had opposed the project from the start. The NGOs were from the USA, and their opposition had been considerably muted following the publication of an article by a highly respected, independent journalist, who had visited Uganda and the site and found, to the contrary, a high level of support for the project.
The delays had been very costly for Uganda. Emergency thermal generation had to be brought in to fill the gap, which involved trucking liquid fuels from Mombasa, so that the end-cost is about 25 ¢/kWh. Power shortages have created serious direct economic losses, in the sense that local industry has suffered from unreliable and expensive supplies: and also serious indirect losses because external investors have gone elsewhere.
Financing negotiations had been complicated by the large number of parties involved, about 12 financiers or guarantor agencies, each of which sent several representatives to meetings. As a result, the process was slow and unwieldy. The aim should be to streamline it, but a problem is that each of the IFIs has its own requirements and constraints.
At $735 million for 250 MW, the project is expensive by international standards. This was partly a reflection of the market at the time of bidding, and the fact that there were only two bidders, one of whom had been significantly more expensive than the other. As the bid prices had been made public at the tender opening, and there were serious time constraints, this weakened the owner's position in finalizing the contract. In similar situations in the future, there is clearly a need to balance the requirement for transparency with preserving the commercial integrity of the negotiations.
The format of the meeting worked well, and there were a number of complimentary remarks from the audience afterwards. The advantages were clear of focusing in on a single project where there have been long commercial negotiations, and understandably different viewpoints.
Session 11: Dam safety and monitoring
Chairman Dr Harald Kreuzer felt that two general trends had emerged from the 10 papers in his session:
a tendency towards a broader notion of safety, taking into account systematic risk-reducing actions in the decision process; and,
the use of high-tech equipment and refined analysis in supporting dam monitoring.
In the first category, the following are examples were presented:
the use of Hydroplus fusegates at the Canton dam in Oklahoma, USA, which were not only to double spillway capacity, but also to enhance reliability, lowering the operational risk to that of an ungated spillway (this was presented by S. Chevalier of Hydroplus, France);
abandoning a Portuguese AAR-damaged arch dam and replacing it with a new one after a comprehensive risk-based comparison of options (presented by J. Cunha, of EDP, Portugal)
; designing a double geomembrane waterproofing system for an artificial snow production reservoir, based on minimizing costs and environmental impacts (presented by A. Scuero of CARPI, Switzerland).
In the second category were:
photographic 3D texturized laser-scanned virtual modelling of the Cabora Bassa dam, to support traditional monitoring of the arch dam exposed to AAR (presented by A. Berberan, Portugal);
the seismic evaluation of dam safety at a pumped-storage project in Indonesia (presented by N. Mulyanto of PLN, Indonesia);
the use of expert systems for managing the safety of existing dams to comply with Russian regulations (presented by N. Ivashchenko of of Zenon NSP, Russia).
a presentation on chemical expansion of concrete showed typical case histories and made delegates aware of present efforts to cover this important impediment on dam integrity (by R. Charlwood, USA and presented by J.G. Warnock, UK).
Malcolm Dunstan (of the UK) presented an overview of RCC development worldwide with emphasis on East Asia.
A deep impression was left by the presentation by P. Rizzo's (USA) on the rehabilitation of two US schemes; Saluda dam and the restoration of the 2005 Taum Sauk upper reservoir failure. The latter was thought-provoking: overtopping of a poorly compacted CFRD, caused only by operational human error on a 'sunny day' (no meteorological impact), and this in a country with stringent dam safety regulations. It is disconcerting to imagine how many safety gaps may still be concealed in spite of the profession's rigorous effort to unearth them.
Session 12. Development prospects and project planning
This session was chaired by Niels Nielsen, Joint Secretary of the International Energy Agency, who summarized it as follows.
Projects from Asia, Europe and South America had been presented, covering topics which ranged from hydropower potential and development, to construction methods and costs. While internationally diverse, the challenges faced had many commonalities. Provision of flood protection, irrigation, navigation and local infrastructure were stressed, in addition to power generation, and the management of environmental and social issues was covered. The Three Gorges Project in China is always an interesting subject, highlighting the benefits of huge multipurpose projects. While flood protection for up to 15 million people represents the first priority, power generation of 22 400 MW from thirty-two 700 MW units producing 100 TWh of electricity annually, fuels economic growth in the region. A third priority is navigation, with a 660 km waterway upstream from Shanghai through a series of locks capable of lifting a 10 000 tonne vessel over the 113 m of head. The presentation showed the many areas and phases of construction.
Hydropower development has a long and important history in the host country, Slovenia, with the first plant having come on-line at the beginning of the 20th century. Most development occurred in the second half of the century, and hydropower, which now shares electrical production with fossil and nuclear energy, is an important contributor to both the national economy and the electrical system. Hydropower potential was presented in terms of hydrology across the major river systems, and future development plans, which could involve the implementation of up to 42 plants with a combined installed capacity of 2480 MW by 2030.
Following the general overview, specific development plans for the Slovenian river with the greatest potential were presented. Truly a multipurpose project, the development of 180 MW of hydropower in the lower reaches of the Sava river basin will be combined with flood relief, irrigation, navigation and local infrastructure improvements. Of particular interest will be the alignment of this project, through stakeholder consultation, with local, regional and national priorities.
Providing reliable first order estimates of the costs of small hydro plants, at early stages of study, has always been a priority, and a presentation on the use of empirical formulae to achieve this goal was insightful. The formulae, developed using statistical data on small hydro costs from the UK and other parts of Europe, were presented both in terms of the overall cost of the project and specifically, the electro-mechanical equipment costs. Hydropower's contribution to the Peruvian electricity market was discussed in terms of the overall energy situation, government initiatives for hydropower development and a specific hydropower project. While hydropower provides a significant proportion of the country's electricity, most new demand is being met through inexpensive gas resources. Supply and transmission restrictions are, however, encouraging the Peruvian Government to support increased development of hydropower through financial and tax incentives. These incentives are proving adequate to encourage new hydropower development. Hydropower has a long history in Costa Rica, and is an important component of both the economy and electricity network. Its present contribution is about two-thirds of electrical power. More than 30 hydropower plants were built during the 1990s, and significant future development is planned through until 2020. However, with Cost Rica's extremely rich and varied natural ecosystem, there is an increased awareness that this development must fully take into account environmental and social issues. The presentation focused particularly on ecological river flows to ensure project sustainability.