Water Power and Dam Construction. Issue December 2010
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WWW.WATERPOWERMAGAZINE.COM DECEMBER 2010 31
PLANNING AND PROJECTS
205TWh, of this 120TWh is already developed, 45TWh is protected,
leaving 40TWh for possible further development. Of this, ca. 50% is
small hydro with no storage capacity (run-of-the-river type).
The present hydropower system in Norway has mainly been
designed for supply of rm energy. The system also has some capacity
for producing peaking power but there are also technical, legal and
environmental limitations. With the planned introduction of large
scale, non-regulated renewable energy (eg in offshore wind parks) it is
expected that hydropower will have to provide much more balancing
power and that new capacity has to be built.
Hydropower peaking, and hence rapid variations in flow and
reservoir levels, means new challenges for the operation of the
hydropower system, and may have adverse effects on machinery,
hydraulic structures, dams and tunnels, and also in rivers and reser-
voirs. Increased demands on hydropower for load balancing in the
Nordic and European power system can be met by changed operation
of the existing system, upgrading and refurbishment and developing
new hydropower plants with reservoirs and/or pumping capacity.
BACKGROUND FOR THE HYDROPEAK PROJECT
The Norwegian government is strongly committed to developing
more renewable energy and has recently given research on sustain-
able energy systems high priority, as a means to reduce greenhouse
gas emissions and mitigate the effect of climate change. In 2008 the
Parliament approved funding of eight new Research Centres on
Environmentally Friendly Energy Systems, with a guaranteed basic
funding for eight years. The centres were selected during a two-step
screening process. At rst 28 preliminary applications were screened,
of these 17 were asked to submit a full application and nally eight
of these were approved in February 2009. In this process, both
Norwegian and international expert groups were used to review and
prioritise among the many competing applications.
The eight centres that were nally approved and given funding were:
r Norwegian Centre for Offshore Wind Energy (NORCOWE).
r BIGCCS Centre – International CCS Research Centre.
r Subsurface CO2 storage – Critical Elements and Superior Strategy
(SUCCESS).
r Norwegian Research Centre for Offshore Wind Technology
(NOWITECH).
r Centre for Environmental Design of Renewable Energy
(CEDREN).
r The Norwegian Research Centre for Solar Cell Technology.
r Bio-energy Innovation Centre (CENBIO).
r The Research Centre on Zero Emission Buildings (ZEB).
One of these centres, CEDREN, has the main focus on the environ-
mental design of renewable energy, but also includes environmental
design of power lines for transport of electricity. The main objec-
tive of CEDREN is to develop and communicate design solutions for
renewable energy production that address environmental and societal
challenges at local, regional, national and global levels.
The centre will rene and adapt the environmental impact analysis
methodology originally developed and implemented for hydropower.
These methods will be transferred to other forms of renewable energy
production – initially to onshore wind power and power lines, and
later to offshore wind power, bio-energy and solar energy. Although
renewable energy from water, wind, sun and bio-resources will be criti-
cal in achieving Norway’s targeted greenhouse gas reductions, produc-
tion may entail some negative local effects on the ecology and society,
which may trigger public resistance and conict. Gaining acceptance
for the comprehensive expansion of renewable energy production will
therefore require solutions that minimise negative social and ecological
impact. At the same time, this expansion must be nancially sound
and feature technically stable systems. This will call for a coordinated
and integrated effort involving many scientic disciplines.
Due to the strong interest in the development of wind power, par-
ticularly offshore wind power, the CEDREN project application was
focusing on the need for a better interaction between wind and hydro-
power, including the study of environmental problems associated
with the increasing use of hydropower for power balancing and peak-
ing. One of the main projects in CEDREN is called HydroPEAK.
HYDROPEAK
The full title of the project is “Hydro power development for peak-
ing and load balancing in a European system with increasing use
of non-regulated renewables”. The title points to the fact that the
future hydropower system in Norway may be facing a new opera-
tional regime, compared to the traditional role, to supply rm power
to industry and the consumer market in Norway. The demand for a
much more variable operation, triggered by increasing amounts of
wind power in the future, may lead to new technical, economic and
environmental challenges to the hydropower system.
The objective of the HydroPEAK project is to study how the hydro-
power system can be used to support increasing amounts of non-
regulated renewables and what type of adaptions that are needed
both in the existing and future hydropower system. Some specic
project aims are:
r To identify the changes in load characteristics in the hydro system
in the new load scenario.
r To identify related technical and environmental problems in the
hydropower system.
r To develop methods for mitigating or reducing negative effects.
r To develop improved methods for optimising operation of the
hydropower system.
r To develop knowledge and methods for planning upgrading/refur-
bishment to meet the new demands on the hydropower system.
r To identify needs for new hydro in a new operational regime.
Above, from left to right: Figure 2 – Svartevatn, one of the largest hydropower
reservoirs in Norway; Figure 3 – The 130m high Svartevatn am regulates a
reservoir of 1400Mm
3
; Figure 4 – A power plant in Tinnelva in Norway
32 DECEMBER 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION
PLANNING AND PROJECTS
IWP& DC
r To build capacity within selected areas (MSc and PhD students).
r To disseminate information and project results in Norway and
internationally.
The HydroPEAK project consists of eight work packages, most of
them include a PhD or PostDoc since the intention is not only to do
useful research, but also to build up new research capacity and con-
tribute to the recruitment of experts for the hydropower sector. There
are six PhD students and one Post-Doc in the project, the rst started
already in 2009, while the last two will start up by the end of 2010.
HydroPEAK’s project leader is Professor Ånund Killingtveit
(aanund.killingtveit@ntnu.no). The project has a budget of 37 Mill
NOK (US$6.2M) and it will be nished in 2014. It is nanced by 50%
from the Norwegian Research Council, 25% from the hydropower
industry and 25% in kind contributions from the research institutions.
A brief description of the main content in each WP is given below.
WP1: Scenarios and dissemination
The main purpose is to generate scenarios for future development of the
renewable capacity in Europe and its impact on the hydropower system
in Norway. Technical, economic and social premises for a ‘hydrope-
aking’ regime/market and important benets and drawbacks will be
discussed. The scenarios will be a framework for discussion and coordi-
nation in the project. A group of interested users and scientists will par-
ticipate in the scenario formulations and later meet at regular intervals
to contribute advice and recommendations during the project.
Project leader: Eivind Solvang (Eivind.Solvang@sintef.no)
WP2: Hydrology
Anticipating increased demands from non-regulated energy production,
the management of hydropower reservoirs for peaking or load balanc-
ing will require improved inow prognosis tools for both long term
management and short-term peaking operation, including ood man-
agement. Emphasis is set on improving these tools for short-term step
simulation and improved model updating from observational data.
Project leader: Sjur Kolberg (Sjur.A.Kolberg@sintef.no)
WP3:The impact of short term effects on long term hydro scheduling
The increased variability of hydropower is not well represented in the
long term scheduling models in use today. The limited representation
of short term effects in these models may increasingly lead to incor-
rect water values and a non-optimal long term use of the reservoirs.
Activities in this work package include: i) Taking into account the
turbine related costs of rapid variations ii) A better representation of
time delays, also for discharge and bypass constraints iii) The repre-
sentation of new types of environmentally based and more dynamic
constraints and iv) Reserve markets
Project leader: Gerard Doorman (Gerard.Doorman@elkraft.ntnu.no )
WP4: Pumped storage plants
Reversible pump turbines (RPT) are well suited for load governing
and also for grid support regarding frequency and voltage governing.
Increased amount of non-governing power will result in a major change
in operation of the Norwegian RPT-plants. Today’s RPT plants are not
able to meet the challenge of changing between pump- turbine and con-
denser mode fast enough to meet the demands on the grid. Topics to be
investigated are i) Evaluate the demands for change in modes of opera-
tions ii) System dynamic evaluation of existing RPT-plants iii) Develop
effective systems for altering between pumping and turbining.
Project Leader: Torbjørn Nielsen (torbjorn.nielsen@ntnu.no )
WP5: Frequency and load governing
A more varying power marked as well as a more dominating element
of non-governing power, will challenge the existing governing and
control systems. The governing stability is initially robust with good
stability margins. Wind power will not contribute positive and result
in reduced stability margins. The water power system will be exposed
to more rapid and more frequent load changes which will result in
pressure surges in penstocks and conduit system. Already there have
been incidents causing higher loads on equipment and increased sand
erosion. In quite a few occasions, mass oscillations have been the
cause for emptying sand traps through the machinery.
Project Leader: Torbjørn Nielsen (torbjorn.nielsen@ntnu.no )
WP6: Effects of load uctuation on tunnels and associated hydraulic
structures
Transients may destabilise the tunnel roadway and scour deposits from
sand traps, resulting in sand transport and turbine damage, and also
destabilise entrapped air pockets resulting in blow outs. Pore pres-
sure variations may destabilise the rock mass and trigger rock falls.
Hydropower intakes and tunnels are generally poorly instrumented
and monitored, and hence reliable data on loss of water, friction losses,
air and sediment problems are virtually non-existent. In order to study
the hydraulics of tunnel systems it is also necessary to develop reliable
monitoring methods. Project Leader: Leif Lia (Leif.Lia@ntnu.no )
WP7: Physical effects of load uctuations in rivers and reservoirs
Fluctuating water levels may destabilise banks along lakes and rivers
and trigger slides. Frequent ood waves may increase scouring. In
total this may lead to increased sediment and nutrient transport. Also,
hydraulic structures like dams, weirs, bridges and revetments etc will
be subjected to frequent uctuations in hydraulic loadings which may
have a destabilising effect. A general increase in the variability of river
ow and more frequent oods due to climate change is likely to inten-
sify these problems. Project Leader: (Nils.Ruther@ntnu.no )
WP8: Ice problems in rivers
A more uctuating production schedule could have adverse impacts
on ice conditions, particularly if periods with low production permits
an ice cover to form which is subsequently broken when releases are
increased (mechanical ice-breakup). Also, predicted climate change
towards a warmer winter climate is expected to create more frequent
changes between ice forming periods and mild periods with increased
river ow resulting in ice break up and ice-runs, especially in unregu-
lated rivers. This could lead to more frequent ice runs which will have
negative impacts both on the environment and on technical installa-
tions on the river, for example hydro intakes, bridges and revetments.
Project Leader: Knut Alfredsen (knut.alfredsen@ntnu.no )
USER INTERACTION AND INVOLVEMENT
Both CEDREN and the HydroPEAK project have been planned in close
cooperation with users, both within the hydropower industry, consult-
ants and the energy and water management institutions in Norway. A
number of national and international partners in Norway, the Nordic
countries, Europe and North-America are participating actively or as
advisors. User groups are set up in all projects to disseminate informa-
tion and get user feedback at all levels. Most of the research involves
eldwork and lab work, and the increased funding of laboratory and
eld data collection equipment is an important contribution to improve
research quality and to recruit MSc- and PhD-students.
Ånund Killingtveit is a Professor of Hydrology and Water
Resources Engineering, Department of Hydraulic and
Environmental Engineering, Norwegian University of
Science and Technology. N-7491 Trondheim, Norway.
Email: aanund.killingtvei
References
IPCC (2007): Climate Change 2007. Impacts, Adaptation and Vulnerability.
Contribution of Working Group II to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change Editor Parry et al.
Capros, P. , Mantzos, L. , Tasios, N. , De Vita, A. and Kouvaritakis,
N. (2009): EU energy trends to 2030 — UPDATE 2009 Luxembourg:
Publications Office of the European Union, 2010 ISBN 978-92-79-16191-9.
doi:10.2833/21664
SRU German Advisory Council on the Environment (2010): Climate-friendly,
reliable, affordable: 100% renewable electricity supply by 2050. Statement
Nr. 15 ISSN 1612-2968
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34 DECEMBER 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION
PLANNING AND PROJECTS
Sustainable considerations
Lawrence Haas and Voradeth Phonekeo from the Mekong River Commission Secretariat
give an insight into sustainable hydro development in the Lower Mekong River Basin
[1]
T
HE Mekong River Basin in Southeast Asia is one of the
most active regions in the world for hydropower devel-
opment. The number of operating and proposed hydro-
power schemes in the Mekong calls for considering
hydropower from both project and basin-level sustainable devel-
opment perspectives.
The Mekong River Basin is dened as the land area surrounding
all the streams and rivers that ow into the Mekong River and even-
tually into the South China Sea. The basin includes parts of China,
Myanmar and VietNam, nearly one third of Thailand and most of
Cambodia and Lao PDR. With a total land area of 795,000km
2
the
basin is nearly the size of France and Germany combined.
HYDRO PLANS
Hydropower is part of the renewable energy endowment of the
Mekong region. Especially with the revival of interest in 14,000MW
in 12 hydropower schemes on the Lao, Lao-Thai and Cambodian
reaches of the Mekong mainstream, a key challenge governments face
is how to place decisions about the management and development of
hydropower in a river basin perspective.
The main inter-governmental mechanism for coordinating efforts for
sustainable development and use of Mekong water and related resourc-
es is the Mekong River Commission (MRC). The MRC was formed in
1995 through the Agreement on the Cooperation for the Sustainable
Development of the Mekong River Basin, which was signed by the
governments of Cambodia, Lao PDR, Thailand and VietNam.
As well as creating the commission, this agreement set out prin-
ciples and procedures for joint management of their shared water
resources and the development of the economic potential of the river
to reduce regional poverty and increase people’s welfare. In 1996,
China and Myanmar became Dialogue Partners of the MRC.
STATE OF THE MEKONG RIVER BASIN
The MRC’s 2010 State of the Basin Report provides an overall picture
of the basin in terms of the economy, the environment, the people and
their livelihoods [2]. In broader terms, the report notes that despite
sustained economic growth over the past two decades, much of the
Mekong basin itself remains among the world’s poorest areas. Many
parts of the basin have poverty rates of up to 40%. By 2008, per capita
electricity consumption only reached two-thirds of the developing
country average. The growing income gap between urban and rural
populations is an increasing concern. Many basin residents still rely on
water and related resources for livelihood, nutrition and culture.
Recently, development of water resources in the Mekong river
basin has started to accelerate, in particular in the hydropower and
irrigation sectors, amid renewed calls by governments for private
sector nancing. Governments of the basin countries increasingly
recognise that developing the economic potential of the Mekong
River sustainably will help efforts to boost growth in mutually
benecial ways, alleviate poverty and improve livelihoods. But
the hydropower opportunities especially need to be weighed up
against the potential risks to the environment, sheries and peo-
ple’s livelihoods.
The sheries in the Lower Mekong basin are vast, even by world
standards. The capture shery yield from the Mekong is approxi-
Above: The fisheries in the Lower Mekong Basin are vast, even by world stand-
ards. Over 65M people depend upon them in the region
WWW.WATERPOWERMAGAZINE.COM DECEMBER 2010 35
PLANNING AND PROJECTS
Sustainable considerations
mately 2% of the total world marine and freshwater capture shery.
From a sheries perspective, the Mekong is not just another river
system. It is extremely important for the livelihoods and nutrition of
65M people in the Lower Mekong Basin, particularly in terms of its
vast sheries resources.
DRIVERS OF ACCELERATED DEVELOPMENT
There are several factors driving the increased interest in developing
renewable energy sources for power needs, including hydropower, in
the Mekong Basin.
The rapid pace of export-led growth comes on top of efforts to
improve electricity access in urban and rural areas, amid urbanisa-
tion and underlying population growth. Volatility in the international
price of oil and gas and concerns over climate change also serve to
intensify the focus on hydropower. At present, 85% of power gen-
eration in the MRC Countries is thermal and the region as a whole
imports approximately 22% of its energy for electricity generation
(coal, oil and gas). This is set to rise.
Mekong governments (especially Lao PDR and Cambodia) see
the potential earnings from electricity export as a means for reduc-
ing national debt burdens and improving cash-ow, and expanding
cross-border power trade to reinforce regional economic integration
and regional energy security policies.
There are currently 135 existing and potential hydropower projects
in the lower basin. Slightly over 10% (3235MW) of the estimated
large scale hydroelectric potential of 30,000MW is now utilised on
Mekong tributaries. Most of this is from projects completed in the
past two decades. A further 3209MW are currently under construc-
tion on the tributary systems.
One indication of the relevance, immediacy and scale of the sustain-
ability challenge is offered in the MRC’s recent basin development plan
(BDP) scenario assessment exercise. In this, the BDP notes that up to
41 large hydropower schemes on LMB tributary systems are proposed
by 2015 [3]. This compares to 15 LMB schemes in the baseline case
for 2000, an increase of 26 large dams. The 20-year probable future
scenario (PFS) sees up to 71 large hydropower schemes operating on
LMB tributaries by 2030. These would have a combined active daily-to-
seasonal storage and ow regulation which is almost double the storage
of Lancang-Mekong dams in Yunnan Province in China.
KEY SUSTAINABILITY CHALLENGES
The rapid pace of hydropower development in the Mekong highlights
the importance of assessing the cumulative and transboundary impacts
of hydropower operations, including the consequences for river ow
regimes, sh passage, water quality and sediment ow and sediment-
nutrient balances impacting on sh and agriculture productivity. These
cumulative impacts will become more important as the number of dam
projects in the Mekong continues to increase in the foreseeable future.
One major anticipated consequence of hydropower development is
an increase in regional dry season ows as water stored in the ood
season is used to generate electricity in
later months. It is not just the distri-
bution and volume of seasonal ows
that are important. The timing of the
onset of the different seasonal changes
vary little from year-to-year so any
small change could have potentially
large environmental consequences
that translate into impacts on sheries
resources. Another long-term impact
in the Mekong context is sediment
trapping. There is also the question
of the degree of impacts from barri-
ers to sh migration that can be tol-
erated, changes in sediment transport,
and changes in the ecosystems when
the hydrological regime including the
ood pulse is altered.
The re-regulation of ows can have
beneficial effects, to the extent that
higher ows occurring downstream in
the dry season make mainstream run-
of-river hydropower schemes in the
LMB nancially more attractive. They
also increase the potential for irrigation
and can reduce salinity intrusion in the
Mekong delta. The construction of dams
also offers an opportunity to improve
river navigability by providing more reli-
able and consistent water depths.
One key sustainability challenge is the
understanding of the many development
synergies and trade-offs hydropower has
Above: Ngum dam on the Nam Ngun river is a typical example of a tributary project
Below, left: Mapping out the member states of the Mekong River Commission;
Below, right: A summary of dam development in the region
36 DECEMBER 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION
PLANNING AND PROJECTS
with the different water-related sectors, such as those synergies between
irrigation and hydropower, and the trade-offs between hydropower and
sheries.
So how is the MRC, as an inter-governmental river basin organisa-
tion, responding to the hydropower sustainability challenge?
In keeping with its mandate, the MRC is introducing a more holis-
tic approach to the assessment of risks and opportunities of hydro
development. This is through a number of complementary steps,
which include strategic studies, data and analysis, preparation of
guidance materials and stepped-up dialogue with government, private
developers and civil society on sustainability issues and tradeoffs.
1) Launching the MRC initiative on sustainable hydropower
The evolution of MRC’s support to member states in the hydro-
power sector is characterised by a gradual shift in emphasis away
from the sole promotion of hydropower towards the advance-
ment of sustainable forms of hydropower development and man-
agement, and the transboundary aspects of this.
To give a clear focus on sustainable considerations embodied in
the 1995 Mekong Agreement, the previous MRC Hydropower
Programme was reformulated as the MRC Initiative on Sustainable
Hydropower (ISH). The initiative was formulated in national
and regional multi-stakeholder processes in 2008 and endorsed
by the MRC Joint Committee in 2009. Implementation of this
cross-cutting initiative involves the other MRC Programmes (eg
navigation, sheries and environment) and supports the Basin
Development Plan process.
2) Adopting hydropower sustainability assessment tools for all
stages of the project cycle
Through the Initiative, the MRC has been actively assisting the
member countries to become familiar with hydropower sustain-
ability assessment tools, with the view to eventually establish a
sustainability assessment process to systematically apply to the
whole population of dams in the LMB.
Such tools will enable measurement, analysis and reporting on
progress in achieving sustainable outcomes, as well as highlight
opportunities for improvement, priorities and shared experi-
ences on the emerging good practices among member countries.
At the project level, MRCS will consider adopting the voluntary
Hydropower Sustainability Assessment Protocol (SAP) now being
developed in the multi-stakeholder process led by the International
Hydropower Association (IHA). The SAP is expected to be avail-
able by the end of 2010.
The MRC is also preparing a rapid basin/sub-basin hydropower
sustainability assessment tool (RSAT) that will consider the design
and operation of multiple-projects in a sub-basin. Together these
assessment tools will enable practitioners, planners and stake-
holders to consider steps to improve the sustainable performance
of hydropower at each stage of the planning and project cycle.
3) Initiating strategic studies using multi-stakeholder processes:
balancing opportunities and risks
A recent priority for the MRC has been to assess the long-term
implications of the mainstream dam proposals working with
member states and non-governmental stakeholders. To do this, in
2009, the MRC commissioned the strategic environment assess-
ment (SEA) of proposed mainstream dams. The SEA aimed to
systematically assess the regional distribution of costs and benets
for the different affected interests and sectors, with respect to eco-
nomic development, social equity and environmental protection.
It considers avoidance, mitigation and enhancement strategies
and contributed to the MRCS Basin-wide framework of analysis
linking decisions on hydropower to integrated water resources
management basin development goals.
The SEA was completed in October 2010. It will inform govern-
ment reviews of the project-specic EIAs submitted by developers
for individual projects, and critically, inform how the MRC can
best enhance its support to member countries when they begin the
PNPCA process for any mainstream proposal (see below).
4) Procedures for Prior Notication, Prior Consultation (PNPCA)
The 1995 Mekong Agreement established a series of protocols for
member countries to consult each other if they wish to pursue any
major infrastructure developments on the Mekong or tributaries,
particularly if those developments may have signicant cumu-
lative or transboundary impacts for people or the environment
downstream.
The MRC received 28 notications for hydropower projects on
Mekong tributaries, as of 2009. From 2008, Cambodia, Lao
PDR and Thailand have also provided ofcial conrmation that
they are investigating 12 mainstream hydropower development
options. Ofcial submission for the rst full consultation on a
mainstream proposal was received by MRC in September 2010,
and has recently begun the six-month prior consultation process
with MRC member countries. This submission was for the 1280
MW Xayaburi hydropower project in Lao PDR. The Xayaburi
project developer intends to sell most of the power to Thailand.
PROMOTING DIALOGUE
The MRC is more generally pursuing and promoting dialogue on
policy, planning and technical aspects to advance sustainable consid-
erations in hydropower from project level to basin-wide perspectives.
The MRC role includes:
r 1SPWJEJOHJOEFQFOEFOUBOEJNQBSUJBMBEWJDFSFHBSEJOHFYJTUJOHBOE
proposed projects.
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making processes.
An immediate challenge relates to the rst Mekong PNPCA process
on the Xayaburi project, and ensuring decision-makers and stake-
holders in MRC member countries see the full range of sustainability
issues. The wider challenge is to ensure plans for sustainable development
of the Mekong river basin are linked to the plans for sustainable develop-
ment of the regional power sector.
Lawrence Haas is a consultant and Voradeth Phonekeo
is the project manager for the Initiative on Sustainable
Hydropower, Mekong River Commission Secretariat,
Vientiane, Lao PDR
IWP& DC
References
1 Parts of this paper were previously presented at the 3rd Conference in
Water Resources and Renewable Energy Development in Asia, Sarawak,
Malaysia, 29-30 March 2010, by the authors.
2 See http://www.mrcmekong.org and http://www.mrcmekong.org/ish/
ish.htm
3 Plus the large storage mainstream dams in the upper Mekong basin
(Lancang-Mekong River) in China.
4. MRC website, http://www.mrcmekong.org/
5. MRC State of the Basin Report, 2003 and State of the Basin Report,
2010 (draft under preparation), http://www.mrcmekong.org/programmes/
bdp.htm
6. MRC Strategic Environment Assessment of proposed Mainstream Dams in
the Lower Mekong, 2010 http://www.mrcmekong.org/ish/SEA.htm
pie zometers
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38 DECEMBER 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION
PLANNING AND PROJECTS
I
N 2007, an Electric Power Research Institute (EPRI) report
assessed waterpower potential and development needs in the
US, and conrmed that an additional 10,000MW of conven-
tional hydropower could be conservatively achieved by 2025
through research and development (R&D) support, economic
incentives, and regulatory reform [1]. It was recognised that same
year by the US Department of Interior that an estimated 2500MW
of power capacity could be harnessed simply by incorporating
hydropower plants in existing non-power federal dams, through
the provision of low-carbon energy options that would not require
the construction of new dams [2]. Any hydropower installation,
however, must balance with one other vital factor: the effect of
hydropower systems on local sh populations.
Fish passing through turbines are subjected to injury and mortality
mechanisms that, ultimately, can negatively impact sh populations.
Furthermore, on river systems with multiple dams, these impacts
can be cumulative for those sh having to pass though multiple
projects. Standard downstream passage structures require water to
be spilled or bypassed around the units to provide safe passage ows
for downstream migrants. However, spill and bypass also equate to
loss of generating capacity for the project. The economic impact of
lost generation is not trivial on large river systems like the mainstem
Columbia River. This river system includes 14 dams in both Canada
and the US and generation losses have been estimated at approxi-
mately 693MW of power capacity (potentially US$237M per year)
due to spill required to safely pass juvenile salmon downstream [3].
In response to the opportunity to develop a solution that both
harnesses the available power in our natural ecological systems and
minimises damage to sh populations, Alden Research Laboratories
(Alden) began the development of the Alden turbine in 1995. The
Alden Turbine was designed to enable fish passage through an
operating unit, an effort which would offset the need for alterna-
tive downstream sh bypasses and thus increase hydropower capac-
ity. Its runner is comprised of only three longer-than-average blades
designed to provide ow conditions that are optimal both for per-
formance and for improved sh survival. The turbine has been devel-
oped in multiple phases, the earliest of which included a pilot-scale
laboratory evaluation. This evaluation was performed at Alden for
nearly 40,000 sh of varying species. The results indicated that when
scaled to a full size turbine, survival would range from 97 to 100% –
a signicant improvement relative to existing turbine designs.
EPRI furthered the pilot scale efforts by completing laboratory stud-
ies that examined the relationship between turbine blade leading edge
geometry and injury/survival after blade strike. The study combined
computational fluid dynamics (CFD) simulations and laboratory
experiments to analyse a semicircular (more blunt and gentle) lead-
ing edge prole to an elliptical (sharper) prole. Both the simulated
and experimental studies examined the effects of blade thickness, sh
length, sh orientation at impact, and sh biology (using trout as model
bony sh and white sturgeon as model cartilaginous sh, and eels).
The laboratory results revealed that semicircular leading edge proles
increased the likelihood of post-strike survival for all sh types. CFD
results indicated that the semicircular design initiated greater forces and
moments near the leading edge just before impact, effectively pushing
the sh away from the leading edge. Furthermore, this research indi-
cated that cartilaginous sh and eels had a consistently higher survival
rate under all test conditions when compared to bony sh. The results
suggested that bony sh would have a survival rate of 90% or higher
when sh length was approximately equal to or less than leading edge
thickness. EPRI’s blade strike work signicantly expanded the existing
data on the effects of blade design on injury and mortality. Realising
the opportunity to incorporate these ndings into the Alden turbine
design, EPRI funded improvements to the Alden turbine with a goal
of producing a design that would be competitive with alternatives in
the same operating range. This redesign effort included resizing the
turbine’s scroll and runner, incorporating a semi-circular blade leading
edge, and adding an initial draft tube into the system [4].
ENGINEERING DESIGN
The Alden turbine is currently undergoing preliminary engineer-
ing design under a two-year grant from the Department of Energy
to EPRI. This work is being conducted by EPRI, Voith Hydro and
Alden. The goal of the additional development is to complete engi-
Alden turbine update
The development of Alden
Research Laboratories’ sh-
friendly turbine began in 1995.
Here Norman Perkins from
Alden and Douglas Dixon from
EPRI give an update on progress
WWW.WATERPOWERMAGAZINE.COM DECEMBER 2010 39
PLANNING AND PROJECTS
neering efforts necessary to move the Alden turbine closer to com-
mercial viability. This includes full system CFD analysis to provide
baseline data for future modications and physical model testing.
This current analysis is specically documenting the turbine
ow shear rate, pressure gradients, and minimum pressure, each
of which can be harmful to sh when passing through a turbine.
In addition to the baseline model, Voith also developed a similar
CFD model for an improved design that incorporates alterations
required for fabrication, assembly, installation, and structural
integrity. This enhanced design also underwent modications to
improve ow shear rate, reduce pressure gradient magnitudes, and
increase the minimum operating pressure of the system, resulting
in reductions in efciency losses in the new runner-draft section
of the system as well as more uniform velocity with signicantly
reduced ow separation in the draft region.
As part of this engineering effort, a physical scale model of the
Alden Turbine is being tested at Voith to assess actual performance
before installation in the eld. It is being tested for efciency, power,
cavitation inception, cavitation breakdown, axial thrust, and steady
radial thrust as a function of model gate opening and at head ranges
appropriate for typical projects feasible for this design. Voith will also
assess the system for runaway speed, wicket gate torque, and pressure
variation in the spiral case and draft tube.
In addition to the engineering design work currently underway, EPRI
is soliciting the industry for potential demonstration sites for the rst
turbine installation. One potential demonstration site has been identied
at Brookeld Renewable Power’s School Street Hydroelectric Project
on the Mohawk River in New York State. In a landmark settlement
agreement between a dam owner and interveners in the federal licens-
ing of project in the US, state and federal resource agencies responsible
for the management and protection of shery resources agreed to the
installation of an Alden turbine as a means to pass sh downstream.
In addition to the School Street Project, EPRI is seeking an additional
demonstration site at an existing or new hydropower development. The
additional demonstration site will complement the tentatively planned
installation and testing of an Alden turbine at School Street.
The EPRI Demonstration Site Programme solicited the US hydro-
power industry for applications to host a demonstration of the Alden
Turbine. A project solicitation list of utilities, vendors, and agencies
was created from FERC, EPRI, and Alden sources. Notications
were sent via e-mail to approximately 500 industry contacts to alert
interested parties to the initiation of this project. Interested applicants
submitted project information via a web-based application form. The
application period closed on 1 August 2010.
Alden received a total of 23 applications from 14 utilities. EPRI has
completed an evaluation of all applicants and has created a numeric
ranking of the submitted sites. The ranking criteria included primary
factors (ie, head, ow, and sh species of concern) and secondary
factors (ie, whether or not the project currently bypasses ow, rela-
tive construction logistics, willingness to commit resources, etc.) with
numeric values assigned to responses. Three sites, two in the US and
one in Europe, have been selected for further evaluation.
The tasks scheduled for the last quarter of 2010 include conducting
site visits to the three candidate sites. Site visits will provide Alden
and EPRI staff an opportunity to discuss specic project benets and
issues related to the addition of power generation using the Alden
turbine. During the same trip, Alden engineers will collect and verify
existing site and civil works information and take necessary measure-
ments needed for the feasibility study. A key component of this visit
will be to conceptualise the layout of the turbine, intake/penstock,
and to consider possible construction methods.
The three sites will then be evaluated based upon: applicant com-
mitment; sizing and general layout of turbine and water conveyance;
predictions of sh survival; appraisal level cost estimates; energy
analysis and return on investment; installation schedule; and permit-
ting requirements. EPRI will then create a nal numeric ranking of
the three sites based upon the collected information and select a nal
site in the rst quarter of 2011.
PROBLEMS
The major problem facing further development of hydropower in
the US and around the world is impacts to migrating sh. Protecting
migrating sh has been the number one industry R&D need iden-
tied in numerous workshops held since the 1990s, including the
recently held 2008 EPRI workshop. In the US, considerable untapped
hydropower resources exist, estimated at 60,000MW. However, its
development is hindered by potential impacts to sh.
EPRI’s analyses have concluded that by 2020, it will be techni-
cally feasible to begin reducing CO2 emissions from the US electric-
ity sector while accommodating continued growth in the demand
for power. Expansion of conventional hydropower is an important
component of this projection.
As electricity demand increases concurrently with the emphasis
on generating power renewably, it will be critical to capture the full
extent of the hydropower available to respond responsibly. The value
of the Alden turbine in this response is that it offers utilities a means
to maximise water use for generation without sacricing the equally
important aquatic resources of the river. The R&D efforts outlined
above highlight a comprehensive method for bringing an important
renewable energy technology closer to market. The completion of
an Alden turbine demonstration in the eld will be a sound building
block in advancing this technology to commercial status.
Norman F. Perkins is a Senior Civil Engineer and Project
Manager at Alden Research Laboratory, 30 Shrewsbury
Street, Holden, MA 01520, US. Dr. Douglas Dixon is a
Senior Project Manager in the EPRI Environmental Sector,
3420 Hillview Avenue, Palo Alto, California 94304, US
Above: Alden AHT milling blade; main pic, left: Turbine runner CFD
References
[1]Electric Power Research Institute (EPRI) 2007. Assessment of
Waterpower Potential and Development Needs. Technical Report 1014762,
Palo Alto, CA, March 2007.
[2]U.S. Department of the Interior (DOI), U.S. Department of the Army, and the
U.S. Department of Energy. 2007. Potential Hydroelectric Development at
Existing Federal Facilities, for Section 1834 of the Energy Policy Act of 2005.
[3]Coutant, C.C., R. Mann, and M.J. Sale. 2006. Reduced Spill at
Hydropower Dams: Opportunities for More Generation and Increased Fish
Protection. Prepared for the U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy by Oak Ridge National Laboratory, Oak
Ridge, TN. Report No. ORNL/TM-2005/179
[4]EPRI. 2009. Redesign of the Alden/Concepts NREC Helical Turbine
for Increased Power Density and Fish Survival: Evaluation of Conceptual
Prototype Turbine. Prepared by Alden Research Laboratory, Inc. EPRI Report
No. 1015600.
IWP& DC
DAM SAFETY
The day Wadi Dayqah roared
In a country where waterfalls are almost unknown, the discharging spillway of the Wadi Dayqah
dams in Oman was a dramatic spectacle. Saleh Hamood Al Harthy, M J Hieatt, J K Hall and M
Wheeler describe how the dams have been tailored and tested by two major cyclones
40 DECEMBER 2010 INTERNATIONAL WATER POWER & DAM CONSTRUCTION
T
HE recently constructed Wadi Dayqah dams in Oman
are set in desert terrain against a mountainous backdrop.
Despite the arid climate both the start and completion of
construction were marked by tropical cyclones bringing
torrential rainfall and dramatic oods. The rst cyclone, Cyclone
Gonu, brought unprecedented rains and ooding to Oman. The
second cyclone, Cyclone Phet, completed the lling of the reservoir
within hours and resulted in the rst discharge from the spillway
on a scale that may not be seen again in our lifetime.
The Sultanate of Oman has few permanent surface water resourc-
es. Wadi Dayqah is unique in Oman in that there is some flow
throughout the year and studies pursued by the Ministry of Regional
Municipalities & Water Resources (MRMWR) in the early 1970s
identied Wadi Dayqah as a potential water source. Its catchment
area is approximately 1700km2 and average annual rainfall within
the catchment is 148mm. Much of this rain comes from thunder-
storms that can give rise to ash oods. The wadi has for centuries
been the source of irrigation from a system of aaj, open irrigation
canals fed from a diversion structure across the wadi. This ancient
system is now being fed from the new reservoir and assured of a
continuing supply.
Providing fresh water has long been a major challenge faced by
Omani generations and aaj are an important heritage illustrating
the diligence and determination of the Omani people in building a
civilization in a harsh environment. Aaj rise from within the moun-
tains, owing down in channels and passing through the hills and to
the plains. Some date back more than two thousand years, during
which time Omanis developed special tools and means that enabled
them to maintain these aaj and create new ones to meet the growing
subsistence demands and the development of agriculture, which has
always been an important part of Oman’s economy despite being
short on rainfall.
Dams have played an important role in the development of water
resources in the Sultanate of Oman. Recharge dams have resulted in
an ongoing improvement in the quantity and quality of water in some
areas over recent years due to the water impounded in oods and held
back to allow recharge of groundwater reservoirs. Surface storage
dams in the mountainous areas have provided water to residents in
the adjacent areas thus leading to a secured settlement of people in
their areas, in addition to the agricultural, livestock and economic
development within these communities.
The work on dams in Oman is under the Dams Department of
the Ministry of Regional Municipalities and Water Resources. The
Ministry has constructed over 30 groundwater recharge dams dis-
tributed in the various regions and governorates of the Sultanate
with a capacity to capture over 1000Mm
3
of ood waters. Further
groundwater recharge dams are being constructed. There are more
than 60 small surface storage dams in mountain areas with more
under construction.
Wadi Dayqah dam is the Sultanate’s tallest dam and one of the
region’s major water projects. It will provide water to supply the
Governorate of Muscat. Construction of ood protection dams is also
in progress: a major protection dam has been completed at Salalah
plain in Dhofar Governorate and construction is currently underway
on a protection dam in Wadi Addy to guard against the risk of oods
in the capital, Muscat. The present construction projects are part of
an on-going programme of dam construction studies and implemen-
tation in various governorates and regions.
CONSTRUCTION PROJECTS
The Wadi Dayqah project comprises an RCC main dam, rockll
saddle dam, a water treatment works, pumping station and water
transfer pipelines to supply local towns and to supplement supply
to the capital, Muscat. The contract for detailed design, preparation
of procurement documentation and construction supervision of the
dams and water supply scheme was awarded in early 2005 to a joint
venture led by Black & Veatch International (UK) with NESPAK
(Pakistan) and Su Yapi (Turkey).
The hydrological assessment carried out as part of the design
Above: Fig 1 – The main 75m high dam is constructed of some 600,000m³ of
roller compacted concrete
Above: Fig 2 – The Wadi Dayqah dam is founded within the narrow limestone
gorge through which the wadi flows