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                          TECHNICAL PAPER #5
                       UNDERSTANDING HYDROPOWER
                            Walter Eshenaur
                          Technical Reviewers
                           Roger E. A. Arndt
                            Charles Delisio
                             Paul N. Garay
                         Christopher D. Turner
                             Published By
                   1600 Wilson Boulevard, Suite 500
                     Arlington, Virginia 22209 USA
                 Tel: 703/276-1800 . Fax 703/243-1865
                       Understanding Hydropower
                          ISBN: 0-86619-205-0
              [C]1984, Volunteers in Technical Assistance
This paper is one of a series published by Volunteers in Technical
Assistance to provide an introduction to specific state-of-the-art
technologies of interest to people in developing countries.
The papers are intended to be used as guidelines to help
people choose technologies that are suitable to their situations.
They are not intended to provide construction or implementation
details.  People are urged to contact VITA or a similar organization
for further information and technical assistance if they
find that a particular technology seems to meet their needs.
The papers in the series were written, reviewed, and illustrated
almost entirely by VITA Volunteer technical experts on a purely
voluntary basis.  Some 500 volunteers were involved in the production
of the first 100 titles issued, contributing approximately
5,000 hours of their time.  VITA staff included Leslie Gottschalk
as primary editor, Julie Berman handling typesetting and layout,
and Margaret Crouch as project manager.
Walter Eshenaur, author of this paper, is a research assistant in
the Department of Agricultural Engineering at the University of
Minnesota, where he specializes in energy technologies, particularly
hydropower.  Reviewers Roger E.A. Arndt, Charles Delisio,
Paul N. Garay, and Christopher D. Turner are also specialists in
hydropower.  Arndt, director of the St. Anthony Falls Hydraulic
Laboratory at the University of Minnesota, has taught hydropower
at the university and has written publications on the subject.  He
is currently conducting research on a turbine test facility which
will test various turbine designs.   Delisio, a professional engineer,
is employed at Flack and Kurtz Consulting Engineers.   During
his affiliation with Yale University's Business School, he conducted
a number of feasibility studies for hydropower projects at
existing sites in New England.   Garay, an associate engineer with
F.M.C. Associates, has written many papers on various aspects of
water transportation and energy uses of water.   Turner coordinates
the Microhydro Development Grant of the Appalachian State University.
He is currently managing construction of a microhydro site
at the Cherokee Indian Reservation in North Carolina.
VITA is a private, nonprofit organization that supports people
working on technical problems in developing countries.   VITA offers
information and assistance aimed at helping individuals and
groups to select and implement technologies appropriate to their
situations.  VITA maintains an international Inquiry Service, a
specialized documentation center, and a computerized roster of
volunteer technical consultants; manages long-term field projects;
and publishes a variety of technical manuals and papers.
                       UNDERSTANDING HYDROPOWER
                   By VITA Volunteer Walter Eshenaur
Water quenches our thirst and bathes our bodies, but above all it
provides the foundation for life on this planet.
Through nature's physical laws, water can unleash powerful and
sometimes destructive forces.   One of these forces, governed by
the law of gravity, is demonstrated through the simplest of
phenomena: falling water.  Over the centuries, people have tried
to harness the energy of falling water to their benefit.  Obtaining
this energy can be simple or nearly impossible, depending
upon which laws of nature govern.   In the case of gravity and
water, nature's governing laws provide easy access to this
useful and abundant energy.
Once it is understood that gravity and water can be harnessed to
produce energy, a study of methods to extract this energy efficiently
can be undertaken.  The purpose of this paper is to discuss
several such methods in general terms.   The paper provides a
basic introduction to the science of water power (hydropower),
along with an overview of state-of-the-art technology.   It also
discusses the sequence of events from initial surveys to end
results to provide a well-rounded understanding of the use of
hydropower.  Although there are other methods, this paper focuses
on turbines and waterwheels.
Gravity dictates that water must seek the lowest elevation possible.
From mighty rivers to babbling streams, water flows downhill,
expending energy as it moves.   With this in mind, general
calculations can be used to determine, on a worldwide basis, the
amount of energy available.  Figure 1 provides some general quantities

fig1pg2.gif (600x600)

of world hydropower resources.   In more scientific terms,
this is known as the installed and uninstalled capability to
produce energy.  Directing water to flow over a pre-determined
course permits energy to be extracted, whereas under natural
conditions this may be impossible.
A predetermined course implies human intervention.   It also
implies a need for this type of energy.   Need, coupled with the
ability to extract energy artificially (intervention), provides
the basis for a study of available resources, which in turn
produces quantitative results.   These results can then be used to
design an appropriate hydropower system providing energy based on
need, yet minimizing adverse environmental effects.
Before any detailed analysis of a hydropower system can be understood,
a short history of turbines and the machinery supporting
them must be presented.
Hydraulic turbines and waterwheels are most commonly used to
extract energy from falling water.   Turbines as we know them today
fall into two categories: reaction and impulse.   Reaction turbines
use both pressure and velocity forces of water to produce
torque.  This torque is then used to produce electrical or mechanical
energy.  Impulse turbines derive their torque or power from
the momentum of a jet of water striking a series of blades.  The
waterwheel, however, is the forerunner of both the impulse and
the reaction turbine.
The waterwheel, a distant grandfather of the impulse turbine,
played an important role in prompting engineers such as John
Smeaton of England (1724-1792) to study and improve it until its
efficiency had reached about 70 percent (Arndt et al., 1981).
Development of a turbine using the same basic principles as the
waterwheel was initiated by engineers Zuppinger in 1846 and
Schwamkrug in 1850.  An important step away from the waterwheel
was initiated at that time with the development of a water spout
or nozzle that directs a high-velocity stream of water against
blades set in a wheel.  Along with this development and the description
of an efficient waterwheel as stated by Poncelet in
1826, a group of engineers from California set out to develop an
impulse turbine with an efficiency higher than that of the waterwheel.
Among this group was Lester A. Pelton (1829-1908), who was
responsible for the development of a highly efficient impulse
wheel that bears his name to this day.
The Pelton wheel, or turbine, although quite efficient, was
improved by Eric Crewdson in 1920.   This improvement led to the
development of the Turgo wheel, which boasts even higher efficiency
and simpler construction than either the Pelton wheel or
the waterwheel.
Nevertheless, impulse wheels have been upstaged in recent years
by more complex and efficient reaction turbines.   Reaction turbines
also use water momentum, but pressure forces are added for
increased torque.  The Kaplan or propeller turbine, developed
around the time that Lester Pelton was perfecting his impulse
machine, has been a very popular machine throughout its history.
The Kaplan turbine's high efficiency under low beads (pressures)
accounts for its growing popularity today because many installations
have high flows but low heads.   Other reaction turbines
developed around the same time include the Francis turbine and
other propeller machines.
Hybrid impulse turbines, which circumvent some basic drawbacks of
full impulse machines, are known as cross-flow turbines.  The
first cross-flow turbine was patented by A.G.M. Michell in 1903.
Professor Donat Banki also developed a cross-flow turbine in 1917
that bears his name today.  Because these turbines are simple to
build, they have been widely used in developing countries where
both low cost and simple technology are imperative.
As we can see from the above discussion, contemporary turbine
theory is a mature science.  Today, the majority of research
involves fine-tuning basic designs and increasing the efficiency
of peripheral equipment such as governors (devices used for maintaining
uniform speed in turbines) and electrical generators.
Specific operational theory of various turbines is not within the
scope of this paper.  However, a general theory, covering all
turbines and waterwheels, is provided in this section of the
paper to aid readers in understanding the broad applications of
turbines.  More detailed turbine theory is generally useful only
to builders or manufacturers, and is not necessary for project
developers or engineers.
All hydropower machines--whether reaction, impulse, or waterwheels--are
driven by the same force: gravity.   Gravity causes a
certain potential energy to exist in a body of water.   Using this
energy to provide useful work requires a change in elevation over
time.  Elevation change over time implies a conversion of potential
energy to kinetic energy.  Potential energy can be quantitatively
expressed in many ways, but for the purpose of this
paper, the term "head" will be used.   Read is the expression of a
pressure exerted on a body or part of a body in terms of feet of
water.  Because water is a principal fluid used in hydropower,
this is a useful concept.  Let us take, for example, a lake surface
that is situated 1,000 meters above sea level.   A hydroelectric
plant is to be installed at an elevation of 800 meters
above sea level using the lake water to produce power.   The head,
which is theoretically available to convert potential energy to
kinetic energy, is 200 meters (the 200 meters is arrived at by
subtracting 800 meters from 1,000 meters).   This is known as gross
head, or Hg.  Figure 2 represents a perfect gross head, where the

fig2pg6.gif (600x600)

gross head is the elevation between the upper and lower water
levels.  In reality, this total gross head is not available to the
turbine due to friction losses in delivery pipes (penstocks) and
a velocity head at the outlet (tailrace) which signifies kinetic
energy lost due to velocity.   Once these fractional and velocity
losses have been quantified in the form of head loss, they must
be subtracted from the gross head.   Gross head minus head losses
gives the total head available to the turbine.   This is called net
head, or H. Once H has been determined, other major parameters
describing the turbine can be defined.   These are discussed in the
sections that follow.
Power is defined as the amount of energy that can be produced for
a given H. A simple relation is given by the equation

eq1pg5.gif (353x353)

                                                 (Equation 1)
where P is kilowatts (when metric units are used), Q is
discharge at the end of the penstock, E is the efficiency of the
turbine and W is the weight of the water.
The power of a free jet
of water streaming from the penstock is given by the equation

eq2pg5.gif (285x285)

                                                  (Equation 2)
where g is the acceleration due to gravity, and V is the jet
The efficiency of the general power equation given in the previous
section can be divided into three parts: volumetric,
hydraulic, and mechanical efficiency.   Volumetric efficiency is
defined as the ratio of the water acting on turbine blades to the
total water entering the turbine casing.   For impulse turbines,
nearly all the water entering strikes the blades; thus, this
efficiency is close to one.  The volumetric efficiency of reaction
turbines is virtually the same as impulse, but waterwheels will
be lower due to water spillage.
Hydraulic efficiency is defined as the power input to the turbine
shaft divided by the power input to the turbine blades.   This
efficiency is the lowest of the three efficiencies and varies
widely among designs.
The third type of efficiency is mechanical efficiency.   It is
defined as the power transmitted through the turbine shaft to the
generator.  It describes any mechanical friction losses.
The overall efficiency is the product of the three efficiencies,
                                                  (Equation 3)

eq3pg7.gif (150x393)

where [E.sub.v] and [E.sub.n] and [E.sub.m] are the volumetric, hydraulic and
mechanical efficiencies, respectively.   This overall efficiency
can be used in either designing or selecting a turbine.
Specific Speed
Another equation, independent of the type of machine, would be
useful in choosing a turbine and its proper speed for a particular
site, given a power capacity and net head.   The equation is:

eq4pg7.gif (135x285)

                                                  (Equation 4)
where Omega is the speed of the turbine in radians
per second, D is
the density of water, P is the power (as defined in equation 1),
g is the acceleration due to gravity, and H is the net head.  Note
that because this is a dimensionless number, it can be applied to
any situation.
Another specific speed that is more commonly used is given by the
                                                  (Equation 5)

eq5pg7.gif (108x353)

where [n.sub.s] is the speed of the turbine in revolutions per minute, P
is the power in horsepower or kilowatts, and H is the net head in
feet or meters.  This specific speed is not dimensionless; its
numerical value depends on the system of units being used.  Three
relationships between [N.sub.s] and [n.sub.s]--depending on the system of
[n.sub.s] = 43.5 [N.sub.s] (English units)
[n.sub.s] = 193.1 [N.sub.s] (metric units using metric horsepower)
[n.sub.s] = 166 [N.sub.s] (metric units using kilowatts).
Once the specific speed is known, the proper turbine can be
selected on the basis of each turbine's rated specific speed variability.
Figure 3 shows various turbines and their dimensional

fig3pg9.gif (600x600)

specific speeds.  Waterwheels fall under Pelton and Francis
turbine specific speeds, depending upon whether they are overshot
([n.sub.s] = 1 to 50) or undershot ([n.sub.s] = 30 to 100), and can reach
efficiencies of 70 percent.
Selection of a particular turbine is done by determining the rpm
needed (for electrical generation, rpm is rated according to the
type of generator and gearing, whereas mechanical power will have
installation-specific rpm requirements), and calculating the
power required (based on need) and the head available (site
specific).  Once these parameters are determined, the specific
speed can be found.  As shown in Figure 3, the most efficient
turbine for a particular specific speed should be used.   Selection
of a particular turbine also depends on cost, and the level of
technology desired.
Waterwheels are more difficult to select.   Head and discharge can
be used to select specific designs rather than specific speed.
Design manuals consider economics, low-level technology, cost,
and ease of operation as high priorities in the selection of
waterwheels over turbines.  This implies serious consideration of
waterwheel use in situations where the above factors are important.
An alternative method of turbine selection involves consideration
of gross head and discharge.   Turbines can be selected by using
the quantities shown in Figure 4.   Waterwheels are not shown in

fig4pg10.gif (600x600)

Figure 4, but they nevertheless tall under the Pelton and Francis
turbine categories, probably in the lower, left corner of the
figure.  It should be noted here that for waterwheels, Figures 3 and 4

fig3pg90.gif (600x600)

do not agree.  This is due to the fact that waterwheels
operate best under low heads and low discharges, causing the rpm
to be very low.  Thus, Figure 3 shows that a waterwheel can compete
with a Francis turbine, whereas Figure 4 indicates use of a
waterwheel, not Pelton or Francis turbines.   Generally, both Pelton
and Francis turbines are recommended for use with high net
heads and high discharges, whereas waterwheels are meant to be
used with low net heads and low discharges.
Thus far, we have described specific turbines according to the
names of people who developed them, without describing their physical
characteristics. In this section, these characteristics are
discussed to aid further in the selection of specific water-power
devices.  Again, to facilitate the discussion, water-power machines
are grouped under the following three headings: reaction
turbines, impulse turbines, and waterwheels.
Reaction Turbines
Reaction turbines use both velocity and pressure forces to
produce power.  Consequently, large surfaces over which these
forces can act are needed.  Also, flow direction as the water
enters the turbine is important.
Figure 5 shows the basic design of a Francis turbine.   Francis

fig5pg12.gif (600x600)

turbines include a complex vane arrangement (see Figure 5) surrounding
the turbine itself (also called the runner).   Water is
introduced around the runner through these vanes and then falls
through the runner, causing it to spin.   Velocity force is applied
through the vanes by causing the water to strike the blades
of the runner at an angle.  Pressure forces are much more subtle
and difficult to explain.  In general, pressure forces are caused
by the flowing water.  As the water flows across the blades, it
causes a pressure drop on the back of the blades.   This in turn
induces a force on the front, and along with velocity forces,
causes torque.  Francis turbines are usually designed specifically
for their intended installation; with the complicated vane system,
they are generally not used for microhydropower applications.
Because of their specialized design, Francis turbines are
very efficient yet very costly.
Propeller turbines are popular reaction machines.   In Figure 6,

fig6pg12.gif (600x600)

the components of a specific propeller turbine called the Kaplan
are shown.  Although propeller turbines operate on the same basis
as the Francis turbine, they are not as specifically designed
since both vanes and propellers (on the Kaplan) are adjustable.
Variations include the bulb turbine which houses blades and
generator in a sealed unit directly in the water stream, the
stratflow turbine where the generator is attached and surrounds
the blades, and the tube turbine where the penstock bends just
before or after the blades, allowing a shaft connected to the
blades to protrude outside the penstock and connect to the generator.
Propeller turbines are usually less costly but are used
almost exclusively in large installations.
The speed of reaction turbines ranges from 100 to 200 rpm,
depending upon design and use.   Speed is governed by the movable
vanes, which alter the direction of water entering the turbine.
These vanes in turn vary the pressure forces on the blades,
causing a loss or gain of power and maintaining speed.
Because reaction turbines use pressure forces and thus run under
reduced pressures, a phenomenon called cavitation can occur.
Simply put, cavitation is the boiling of water due to low
pressure.  Water will boil when pressure is reduced considerably;
this phenomenon happens on the low pressure side of a reaction
turbine blade.  Cavitation occurs only at the leading edge of the
blade and as pressures rise again near the trailing edge, cavitation
ceases.  It is important for cavitation to cease because as
the water vapor returns to a liquid state, localized pressures
become tremendous.  Such pressures have the equivalent force of
pounding a sledge hammer against the turbine blade.   Bearing in
mind the power of cavitation, this phenomenon should be reduced
a minimum.  This is accomplished by carefully monitoring flow
velocity and changing flow direction by use of the vanes.  The
advantages of reaction turbines include:
     *   high efficiencies;
     *   excellent power output at low heads;
     *   numerous designs that provide easy tailoring to specific
        installations; and
     *   the flexibility of choosing either horizontal or vertical
The disadvantages of reaction turbines include:
     *   efficiency at specified heads and discharges but inefficiency
        when these vary;
     *   the need for accuracy in installation design;
     *   the possibility that cavitation will occur;
     *   the potential that nonuniform forces will destroy the
     *   very strict design tolerances;
     *   costly civil works; and
     *   high manufacturing costs.
Because reaction turbines--whether Francis or propeller--have
high efficiency and high power output, they are the best waterpower
devices and should be pursued whenever possible.
On the other hand, these turbines are very expensive to build,
highly sophisticated in design, and do not use locally-produced
raw materials, making them unsuitable for use in developing
countries.  Note also that they may not be readily available in
the small sizes needed for small installations.   So, consider
instead the option of using centrifugal pumps, which can be
readily adapted to serve as hydroturbines in any practical power
range.  These pumps are readily available and come in many sizes,
making it possible to satisfy the needs of the small hydropower
customer.  Also, because they are mass produced, they typically
cost less than half as much as the equivalent hydraulic turbine.
In many small-hydro applications, a suitable turbine is simply
unavailable, and the cost of a custom model would be prohibitive.
Centrifugal pumps are easier to install and maintain, and they
are simpler to operate.  In addition, they are available in a
broader range of designs than conventional turbines.   Wet-pit,
dry-pit, horizontal, vertical, and even submersible are just a
few of the types of centrifugal pumps available.
All types of centrifugal pumps, from radial-flow to axial-flow
designs, can be operated in reverse and used as hydraulic
turbines.  Tests have shown than when a centrifugal pump operates
as a turbine:
     *   its mechanical operation is smooth and quiet, and
     *   its peak efficiency as a turbine is essentially the same
        as its peak efficiency as a pump.
One note of caution: a centrifugal pump used as a hydraulic turbine
must be checked by a qualified hydraulic engineer before it
goes into operation to prevent damage to the impeller.   When the
pump operates as a turbine, it rotates in reverse so that operating
heads and power output are generally higher.   To avoid damage
to the impeller, the engineer has to check how much stress the
pump can tolerate caused by the flow and pressure of the water.
Impulse Turbines
Impulse turbines derive their power from a jet stream striking a
series of blades or buckets.   The Pelton wheel is probably the
most well-known impulse machine, but others are now becoming
Figure 7 shows a Pelton wheel.   Notice that one nozzle is being

fig7pg15.gif (600x600)

used, with its jet of water striking one bucket at a time.  Since
impulse turbines operate at atmospheric pressures, cavitation is
not a concern.  However, bucket design is very important because
of the tremendous forces involved.   Buckets are designed so that
the stream of water is split in half and turned almost back upon
itself.  This design extracts maximum energy and negates axial
(along the shaft) torque.  Adding nozzles increases power output
linearly, but a practical maximum is six nozzles.   If the discharge
allows more than one nozzle, this is probably desirable.
Pelton and Turgo wheels are higher speed machines ranging in
speed from 1,000 to 3,600 rpm.   This is advantageous when
electrical generation is necessary, but high speed reduces torque
which may be desirable for mechanical applications.   If speed
regulation in necessary, nozzle velocity can be controlled by
using a needle valve which decreases the water power available.
Figure 8 shows the blade arrangement of the Turgo wheel.  Designed

fig8pg17.gif (600x600)

along the same lines as the Pelton wheel, the Turgo wheel allows
the stream of water to strike several blades at one time.  This
increases the power output since one blade is always under the
full force of the water jet.
Both the Pelton and Turgo wheels are well suited for high head,
low discharge situations since water velocity is the governing
force and may be high under high heads while discharge is low.
Cross-flow turbines use impulse theory yet operate somewhat differently
than Pelton or Turgo wheels.   Figure 9 shows a cross-flow

fig9pg17.gif (600x600)

turbine called the Banki turbine.   Water exiting the nozzle
strikes several blades, producing torque.   The blades direct the
water into the inner area of the turbine.   The water travels
across the inner diameter of the turbine and strikes the blades
again at another location on the turbine, creating additional
torque.  This novel design, though seemingly complex, lends itself
to easy construction on a local basis since this turbine does not
use a high-velocity water jet or special manufacturing techniques
as do the Pelton and Turgo wheels.   Local materials can be used
since the force of the water is distributed evenly throughout the
length of the turbine.
The operating efficiencies of impulse turbines are usually around
80 percent.  Because high head, low discharge sites are common and
efficiencies are high, Pelton and Turgo wheels are easily
installed without the rigorous design typical of reaction
turbines.  Civil works are much less than those of reaction turbines
since impulse turbines are independent of pressure forces.
The speed of cross-flow turbines falls in the same range as that
of reaction turbines.  Regulating the speed is achieved through
nozzle velocity control or by diverting some water around the
turbine, lessening water discharge and velocity.
The advantages of impulse turbines include:
     *   low water discharge requirements;
     *   the efficient use of high heads;
     *   small physical size yet high power output;
     *   high efficiencies;
     *   simple design;
     *   simple civil works;
     *   low maintenance;
     *   low cost; and
     *   low labor input.
The disadvantages of impulse turbines include:
     *   poor power output under low heads;
     *   the possibility of increased wear and tear due to operation
        at high speed;
     *   very strict manufacturing specifications for other than
        crossflow; and
     *   the complexity of regulating the speed of the turbine.
Because of their simple design and low cost, impulse turbines
lend themselves well to minihydropower and microhydropower installations
in remote areas in developing countries.
Of all water-power machines, waterwheels are the simplest in
theory, design, and installation.   In this section, four types of
waterwheels are described: the undershot waterwheel, the Poncelet
wheel, the breast wheel, and the overshot waterwheel.
The undershot waterwheel derives its power from flowing water
under a very low head.  As shown in Figure 10, water passing under

fig10p19.gif (600x600)

the wheel strikes the paddles, causing the wheel to rotate.  Efficiency
of the undershot waterwheel is quite low, and the heads
ranging from 2 to 5 meters are best.
Figure 11 shows the Poncelet wheel, which is similar in design to

fig11p19.gif (600x600)

the undershot wheel.  However, unlike the flat blades of an undershot
wheel, the blades of a Poncelet wheel are curved, creating a
more efficient water interaction by forcing the water to back up
and discharge through a narrow opening.   The Poncelet wheel has a
minimum diameter of 4.5 meters and operates most efficiently
under heads of 2 meters.  Because of design improvements over the
undershot wheel, efficiencies are slightly higher.   A breastwork
of concrete fitted close to the paddles keeps the water backed up
but necessitates trash removal (trash racks) to ensure that
branches or rocks will not enter the system.
The breast wheel shown in Figure 12 is another improvement over

fig12p20.gif (600x600)

the undershot wheel.  This wheel, like the Poncelet wheel, backs
up the water and use the energy created therein.   A close-fitting
breastwork forces the water into the blades to produce torque.
Efficiencies approach 65 percent for high breast wheels (water
entering below the center line).   The fact that breast wheels need
a close-fitting breastwork, a curved bucket design, and a trash
rack usually makes other types of waterwheels more attractive.
Figure 13 shows an overshot waterwheel.   This design allows water

fig13p20.gif (600x600)

to enter buckets at the highest point, and the weight of the
water causes the wheel to turn.   Water discharge is controlled by
a sluice gate to minimize waste through overfilled buckets.  Overshot
wheels are the most efficient waterwheels and can operate
under heads of 3 meters and above.
Waterwheels are easy to build.   They are usually large and rotate
very slowly, usually in the range of 3 to 20 rpm.   Waterwheels
produce high torque and can be used in nonconventional ways.
The advantages of waterwheels include:
     *   simple design;
     *   easy construction;
     *   high torque;
     *   operation under large flow variations;
     *   minimal maintenance and repair: and
     *   low cost.
The disadvantages of waterwheels include:
     *   low efficiencies;
     *   need at times for close tolerances in construction;
     *   slow speed; and
     *   large size.
Waterwheels find their niche where high torque and low speed are
necessary.  In developing countries, the economics of construction,
the level of technology, and the wide range of uses ensure
waterwheels a future in water-power development.
None of the machines discussed above should be applied, however,
if no practical, efficient use can be found.
The use of waterpower falls under two general categories:
mechanical and electrical use.   Mechanical use implies obtaining
power directly from the turbine or waterwheel and using it to
accomplish physical work.  Electrical use implies the generation
of electricity from the turbine or waterwheel and using it to
perform work.
Mechanical Use of Hydropower
Although turbines are used to produce mechanical power, they are
rarely applied that way.  In Third World installations, impulse
wheels are used through gearing mechanisms for grinding, threshing,
or cutting.  These applications are appropriate to each
situation.  Various applications of impulse turbines include:
machines that thresh, grind, and cut grain; sawmill equipment,
and metalworking tools.  Usually drivebelts deliver power to all
of this equipment while reducing speed and increasing torque.
Waterwheels lend themselves ideally to mechanical use.   The foregoing
applications apply as well to waterwheels and sometimes
even more so.  Milling and grinding are especially conducive to
waterwheels where slow rotation is necessary.   Waterwheels also
lend themselves well to the pumping of water or other liquids
since pumps require slower speeds.
Electrical Use of Hydropower
Electrical power generation requires constant speed under varying
loads.  Generators operate at certain speeds, depending upon
construction and electrical requirements.  Uniform speed is very
important and usually quite fast.   Impulse and reaction turbines
are used almost exclusively for electrical power generation in
the United States and Europe.   In the Third World, electrical
power generation is becoming economical, and the use of turbines
is increasing.  Impulse turbines can be connected directly to a
generator, but a speed regulation device must be used in combination
with these turbines in order for the generator to work.
Reaction turbines are usually connected to generators through a
gearbox.  The regulation of speed is also important in reaction
turbines and can become very complex, depending upon the reaction
turbine chosen.
Waterwheels do not lend themselves well to electrical power generation
due to their slow speed and speed-governing problems inherent
in their design.  Thus, electrical power generation is not
recommended with waterwheels.
Economics dictates the feasibility of hydropower installation
even if all other factors are positive.   Two principal economic
characteristics of hydropower are high initial costs and low
operating costs.  In general, a hydropower system requires substantial
initial capital investments to minimize operating costs.
However, there is a point where excessively high capital costs
will create the reverse effect of much higher operating costs.
To reduce initial costs, several cost-cutting steps can be taken:
     *   maintain low administrative costs;
     *   use local labor;
     *   use local materials as much as possible;
     *   build some of the equipment locally;
     *   design an appropriate hydropower system (i.e., one that
        does not require high system efficiency, installation of
        a governor--a device used for maintaining uniform speed
        in a turbine, or recruitment of a full-time staff);
     *   do not provide for a profit margin included in most
        costings for microhydropower installations; and
     *   minimize use of costly technical expertise and supervision.
It is important to note that the steps outlined above are aimed
at Third World situations and represent actual experience.
Methods for determining hydropower installation costs are
difficult in Third World development situations.   Nevertheless,
Figure 14 gives a general idea of the relative costs of hydropower

fig14p24.gif (600x600)

in the United States.  Notice that low head, low-power installations
have installed costs less than high head, high-power
installations.  However, notice that the cost decreases as head
increases and that medium head and power output installations are
the least expensive.  Figure 14 shows relative costs and thus
describes, for all situations, the optimum head to power ratio.
Figure 14 does not factor in the cost-cutting steps listed above,
however.  But by taking these steps, even low head and low-power
sites become economical.
Relative project costs are outlined in Figure 15.   Two options are

fig15p26.gif (600x600)

presented.  The first option describes development situations in
the Third World.  The second option describes situations applicable
to developed countries.  From these two options, one can
deduce that the majority of costs apply to mechanical and electrical
elements and could probably be reduced by following the
steps outlined previously.
This discussion demonstrates that although financial economics
are important in considering hydropower installation, there are
methods of reducing the financial impact to an acceptable level.
Hydropower, as previously discussed, is used primarily for electrical
and motive power generation.   Waterwheels are best used
for motive power by direct coupling to machinery.   Turbines
(reaction or impulse) are best used for electrical power operation
but are being used successfully for motive power as well.  At
this point, the question arises:   "Is hydropower best for my
situation, or should I use an alternate power source?" This is an
important question to consider and to answer as clearly as possible.
While hydropower serves some situations very well, it may
be marginal or totally inappropriate for others.   To determine
when hydropower should be used as opposed to other alternatives,
some discussion of these alternatives is necessary.
With the advent of technology transfer from technology centers in
Europe and North America to developing countries, several energy
sources have been perfected and successfully implemented without
the supporting technology base.   This has provided alternative
energy sources for developing countries without the delay of
technology development.  Hence, solar power either through direct
(photovoltaics) or indirect (steam production) methods, wind
power, methane power, and alternative liquid fuel production (to
name just a few) have become successful power producers in their
own right.  These may also become candidates for consideration
along with hydropower for a particular situation.   To best discuss
hydropower and the alternatives, several alternative energy
sources are summarized and then compared to hydropower.
The sun provides a vast amount of energy to the earth each day.
Depending upon climatic and atmospheric conditions, this energy
may be harnessed and utilized. Two methods are popular (but not
exclusive): photovoltaics and thermal. Photovoltaics employ
silicon wafers or discs that produce electrical current in the
presence of light (not necessarily restricted to visible light).
When many wafers are connected together, the electricity produced
may be used to power electrical machinery, electric lamps, or
charge batteries. This power is in the form of direct current
(DC), however, which is usually not compatible with the alternating
current (AC) produced by regional electric grid systems.
Thus, to power common household appliances that use AC motors,
conversion from DC to AC is necessary with great losses in energy.
This implies either large expenditures to produce inefficient
power, or DC-compatible equipment which may be difficult to
The major drawback of photovoltaics is cost. The cost of producing
silicon wafers (you have to "grow" them) is still high,
despite the fact that it continues to decline steadily. Purchase
of a water pump producing not more than 500 liters per minute and
powered exclusively by photovoltaics would cost U.S. $7,000.00 in
Kenya. This is prohibitively expensive for small communities.
Solar power may also be used to heat liquids or solids that then
transport heat. Steam may be produced through intense concentrations
of solar energy. This steam may be used to power a turbine
(as in hydropower but with steam) for electricity or motive
force. Thermal power, as created by solar energy, may also be
used to heat water for domestic purposes, heat thermal masses for
heat storage (passive solar heating), or even to vaporize gases
as in the Minto Wheel to produce motive force.
Solar energy conversion--either by photovoltaics or thermal--may
be a viable alternative to hydropower if the following conditions
prevail: lack of flowing water, remoteness of site, cost, technology
availability, and end use (what is the intended goal).
Although solar energy can produce electrical power (DC) without
the need for civil works, reservoirs, or expensive turbines and
generators, photovoltaics are nevertheless expensive. Moreover,
in some areas of the world, solar power is not suitable. In
Darjeeling, India, for example, hydropower may be the best choice
simply because of lack of sunshine during the monsoon months.
Over a period of four months, the sun will not shine (except for
about two weeks) because of dense cloud cover. Since power
production by photovoltaics is a function of solar intensity, a
huge and expensive array of solar cells would be necessary. It
would in fact be prohibitively expensive. Thus, if the climatic
conditions are not favorable, solar power as an alternative to
hydropower must be ruled out.
There is great power in the winds. The technological problem is
to extract the power efficiently and without great expense.
Windmills are the most popular form of power production by wind.
Unfortunately, there are many designs available that claim best
efficiency. Efficiency refers here to the ratio of energy
produced to energy available. Available energy in the wind is
great but energy produced by windmills (even the most
technologically advanced) is not more than 30 percent. For
development situations where high technology is scarce, typical
efficiencies are less than 15 percent. This means that 85
percent of the available power has not been extracted.
As with solar power, wind power is dependent upon several factors.
The most important is wind. Wind is not always available.
Some developing countries are not suited for windmills simply
because there is not enough wind (wind speed). Before any consideration
of wind power may be entertained, data either from
weather stations or from local histories must be obtained. If
the average wind speed is less than about 10 km per hour, wind
power will not be viable. Making effective use of wind power as
an alternative to hydropower depends on the amount of wind available,
availability of construction materials, expertise, and end
Wind power, like solar power, can become expensive when it is
needed to provide large amounts of power. Wind power is best
suited for motive power in pumping or turning machinery. Electrical
generation by wind power is probably not viable without
expensive towers, blades, governers, alternators, and batteries.
This comparison to hydropower may, in situations where hydropower
can be implemented, indicate that hydropower is the best choice.
Methane gas is produced easily through fermentation of animal,
crop, and human waste. By anaerobic (absence of oxygen) digestion
in large containers, methane gas can be produced and used for
heating, lighting, or powering internal combustion engines. This
technology is rather simple but construction may be expensive and
it is somewhat labor intensive.
Methane production is viable only where there are sufficient
amounts of the right kind of waste. Vegetable matter (including
crop residues) may be used in the digestion process but may not
produce much methane due to the large cellulose content. The
best waste is animal waste, which, when digested at high temperatures
(about 55[degrees]C), will produce great amounts of methane. To
provide this elevated temperature, all the methane produced may
have to be used unless there is some other inexpensive heat
source for this. Storage and transport of methane gas may be
difficult and expensive. As an alternative to hydropower,
methane may be the closest to actual compatibility of uses. It
can replace hydropower for electrical generation and motive power
by powering internal combustion engines. One problem with methane
as a fuel is the high carbon dioxide, sulfur (hydrogen sulfide),
and water content. All these chemicals have adverse side effects
on engines when used in amounts such as those that come directly
from the digester. Thus, cleaning or "scrubbing" the gas as it
emerges from the digester is necessary before injection into an
engine. This adds to the expense of the digester.
Both methane generation and hydropower require high capital costs
but are relatively low in operating costs. Operator expertise is
necessary for both, also. In sum, methane, as generated by
anaerobic digestion of plant and animal wastes, presents a very
viable alternative to hydropower where the necessary resources
are present. Capital costs are probably lower for methane but
operating costs will almost invariably be higher than those for
The two popular fuels for internal combusion engines are gasoline
(petrol) and diesel. In many parts of the world, these fuels are
very difficult to obtain and are usually very expensive. Internal
combustion engines are prevalent throughout the world. If
other fuels can be developed to replace the expensive fossil
fuels such as gasoline and diesel, they would then present viable
alternatives to hydropower.
Several fuels are already in use. They include: methane (discussed
previously), butane, propane, sunflower oil, and peanut
oil. While there may be other possibilities, these represent the
most common at this time. Butane and propane are gases which are
normally used for heating or lighting. They contain high amounts
of energy but are not always available, especially in remote
areas. They can also be expensive to purchase and transport.
Sunflower and peanut oils are just now becoming popular for
diesel engines. They contain high amounts of energy but if not
purified extensively, will cause contamination and subsequent
destruction of the engine. None of these alternate fuels contains
as high an energy content per unit volume as gasoline or diesel.
Thus, more must be used to obtain the same output from an engine.
Butane and propane are usually obtained from underground deposits
(along with crude oil) and thus are not available worldwide.
Methane, as discussed above, can be produced locally and with low
technology. Sunflower and peanut oils can also be produced
locally but require expensive pressing and purification processes
before they can be used. If economics allow use of alternative
internal combustion fuels to produce electricity and motive power,
they present good alternatives to hydropower.
This description of alternatives to hydropower is not meant to be
exhaustive or complete. If hydropower is a possibility for a
particular situation, consideration of other alternatives is
necessary from an economic, social, and end use perspective. By
comparing the alternatives presented above, one can begin to
determine whether or not hydropower is the best choice. However,
it is very important to consider hydropower alternatives in more
depth than given above. This is a technological discussion but
the importance of social and cultural considerations is just as
important, if not more so. Keep in mind, however, that hydropower
is a very efficient, clean source of energy and should be
seriously considered in light of the alternatives for a particular
Site selection, flow diversions, and environmental effects are
among the important factors that must be considered before hydropower
installation begins. The proper sequence of events must be
adhered to for installation to be successful.
Economics strongly dictates the size of the hydropower site.
Small hydropower sites become less economical due to the nonlinearity
of costs and benefits. As the size increases, the
benefit-cost ratio increases, providing more desirable outcomes.
This is unfortunate, and many small installations, while seemingly
ideal, are not implemented for this reason. Much has been
done, however, to offset these negative economic indicators.
Hydropower development in Pakistan, for example, has been encouraged
through the "Small Decentralized Hydropower (SDH) program"
(Inversin, 1981). This program assists in very small (micro)
hydropower development and has been successful because the following
objectives were met:
    *   readily available materials were used in nonconventional
    *   hydropower designs were suited to the local realities;
    *   the community was involved in the initiation, implementation,
       management, operation, and maintenance of the hydropower
Thus, small, decentralized hydropower in development situations
is clearly feasible. Due to transportation, material and financial
difficulties of larger hydropower installations, small-scale
hydropower installations are very desirable. However, as stated
previously, steps to develop hydropower on any scale must be
taken carefully and in sequence.
Information on the availability of power must be obtained before
any other steps are taken. Information on elevation differences,
amounts of water available, and construction feasibility also
must be obtained. Important preliminary questions to be answered
    1.   How much rainfall occurs over a year's time and how is
        it distributed throughout the year?
    2.  What type of water fall is available or must it be artificially
    3.   How much water is available for use?
    4.   What is the topography of the area under consideration
        and how can it best be used?
    5.   Is the community willing to participate in such a project?
    6.   What type of community education is necessary and how
        will it be implemented?
If positive answers to these six questions can be obtained,
subsequent steps can then be taken.
Financing also must be obtained. This can be difficult in Third
World development situations where few grants or loans are available
and where communities are not able to raise money themselves.
If financing is unavailable, the project cannot be implemented.
No hydropower project is free.
Environmental concerns are very important especially when major
flow diversion or retention is required. Studies addressing the
long-term effects of a hydropower project must be done. If these
studies show that the environmental effects are minimal (there
will always be some), the project can continue. If, on the other
hand, the environmental effects are negative, reconsideration is
necessary with the possibility of project termination.
If permits must be obtained, that must be done long before any
design or construction is initiated.
Financial returns must be negotiated and benefits must be tabulated
to ensure continuing installation viability.
Once the above steps are taken, design of the physical layout can
begin. After exhaustive designs are completed, construction can
begin. When the project is completed, the hydropower system must
undergo rigorous testing. If the results of the tests are positive,
operation of the hydropower system can begin.
Barnessing the energy from falling water is a relatively easy
technology compared to internal combusion engines. By applying
the methods described in this paper, abundant and clean power can
be appropriately obtained.
Alward, R.; Eisenbart, S.; and Volkman, J. Micro-hydropower:
Reviewing an Old Concept. Butte, Montana: The National
Center for Appropriate Technology, 1979.
Arndt, R.E.A.; Farell, C.; and Wetzel, J.M. "Hydraulic Turbines."
Paper presented at the Small Scale Hydropower Feasibility
Studies Seminar of the University of Minnesota, Minneapolis,
Minnesota, 26-30 July, 1981.
Arndt, R.E.A.; Farell, C.; and Wetzel, J.M. "Hydraulic Turbines."
In Small and Mini Hydropower Systems, pp. 6.1-6.64. Edited
by Jack J. Fritz. New York: McGraw Hill, 1984.
Breslin, W.R. Small Michell (Banki) Turbine: A Construction
Manual. Arlington, Virginia: Volunteers in Technical Assistance,
Deudney, Daniel. "Rivers of Energy: The Hydropower Potential."
Worldwatch Paper 44. Washington, D.C.: The Worldwatch Institute,
June 1981.
Durali, M. Design of Small Water Turbines for Farms and Small
Communities. Prepared for the Office of Science and Technology,
United States Agency for International Development
by the Technology Adaptation Program, Massachusetts Institute
of Technology, Cambridge, Massachusetts, 1976.
Fraenkel, P. The Power Guide: A Catalogue of Small Scale Power
Equipment. New York: Charles Scribner's Sons, 1979.
Fritz, Jack J., ed. Small and Mini Hydropower Systems. New York:
McGraw Hill, 1984.
Hamm, H.W. Low Cost Development of Small Water Power Sites.
Arlington, Virginia: Volunteers in Technical Assistance,
Inversin, A.R. A Case Study: Micro-hydropower Schemes in Pakistan.
Washington, D.C.: National Rural Electric Cooperative
Association, 1981.
McGuigan, D. Harnessing Water Power for Home Energy. Charlotte,
Vermont: Garden Way Publishing Company, 1978.
Ovens, W.G. A Design Manual for Water Wheels. Arlington, Virginia:
Volunteers in Technical Assistance, 1975.
Sorumsand Verksted A/S Company. Mini Hydro Turbines. Sorumsand,
Norway: Sorumsand Verksted A/S Company, 1981.
Tudor Engineering Company. Reconnaissance Evaluation of Small
Low-Head Hydroelectric Installations. Washington, D.C.: U.S.
Department of the Interior, Water and Power Resources, Engineering
and Research Center, 1980.
Volunteers in Technical Assistance.   Overshot Waterwheel: Design
and Construction Manual. Arlington, Virginia: Volunteers
in Technical Assistance, 1979.
                        SUGGESTED READING LIST
Microhydropower Handbook Volume I and II. Available from U.S.
Department of Commerce, National Technical Information Service,
5285 Port Royal Road, Springfield, Virginia 22161 at U.S. $32.50
for Volume 1 (DE83-006-697) and $31.00 for Volume II (DE83-006-698).
Written for persons who want to design their own site for
producing electricity of under 100 kilowatts output. With over
800 pages (both volumes included), this is probably the most
comprehensive work on the subject.
Harnessing Water Power for Home Energy, by Dermat McGuigan. This
book, published by Garden Way Publishing, gives examples of
microhydroelectric projects from all over the world. It is a
good introduction to hydropower. Priced in most book stores at
under U.S. $8.00.
Micro-Hydro Power: Reviewing an Old Concept, by the National
Center for Appropriate Technology, P.O. Box 3838, Butte, Montana
59702-3838. This publication provides a good overview of
microhydropower for a moderate price (less than U.S. $5.00).
Guide to Development of Small Hydroelectric and Microhydroelectric
Projects in North Carolina, by John Warren and Paul Gallimore.
This handbook on hydropower is available from the North
Carolina Alternative Energy Corporation, Research Triangle Park,
North Carolina 27709.
More Other Homes and Garbage: Designs for Self-Sufficient Living.
Published by the Sierra Club. Pages 75-92 deal with producing
electricity from a stream. This book, like all of the other
books listed above, includes techniques for measuring head and
stream flow.
Homemade Electricity: An Introduction to Small-Scale Wind, Hydro,
and Photovoltaic Systems. Available from Superintendent of Documents,
U.S. Government Printing Office, Washington, D.C. 20402.
Directory of Manufacturers of Small Hydropower Equipment, by
Allen R. Inversin. Available from the Small Decentralized Hydropower
(SDH) Program, International Programs Division of the National
Rural Electric Cooperative Association, 1800 Massachusetts
Avenue N.W., Washington, D.C. 20036.
The National Center for Appropriate Technology
P.O. Box 3838
Butte, Montana 59701 USA
Volunteers in Technical Assistance
Suite 200
1815 North Lynn Street
Arlington, Virginia 22209 USA
The following are design firms, consultants, and contractors with
expressed interest in hydropower development. This list
encompasses a spectrum ranging from small consultant firms with
minimal hydropower experience to large engineering firms that can
manage a project from conception through construction. A
potential user of the services of any of the firms listed should
satisfy himself that the firm has the capability and experience
required for the service desired.
U.S. Firms
Edward A. Abdun-nur
Consulting Engineer
3067 South Dexter Way
Denver, CO 80222 USA
(303) 756-7226
Acres American
Liberty Bank Building
Main at Court
Buffalo, NY 14202 USA
(716) 853-7525
Allen & Boshall, Inc.
Attn: W. Lewis Wood, Jr.
P.O. Box 12788
Memphis, TN 38112 USA
(901) 327-8222
661 Harbour Way South
Richmond, CA 94804 USA
(415) 237-5490
Applied Energy Planners, Inc.
Attn: E. Fletcher Christiansen, Pres.
P.O. Box 88461
Atlanta, GA 30338 USA
(404) 451-8526
Appropriate Technologies, Inc.
Attn: George L. Smith
P.O. Box 1016
Idaho Falls, ID 83401 USA
(208) 529-1611
Associated Consultants, Inc.
Attn: R.E. Palmquist
3131 Fernbrook Lane North
Minneapolis, MN 55441 USA
(612) 559-5511
Auslam & Associates, Inc.
Economic Consultants
Attn: Margaret S. Hall
601 University Avenue
Sacramento, CA 95825 USA
Ayres, Lewis, Norris & May, Inc.
3983 Research Park Drive
Ann Arbor, MI 48104 USA
Banner Associates, Inc.
Attn: Joseph C. Lord
P.C. Box 550
309 South Fourth Street
Laramie, WY 82070 USA
(307) 745-7366
Barber Engineering
Attn: Robert W. Ross, Project Coordinator
250 South Beechwood Avenue, Suite 111
Boise, ID 83709 USA
(208) 376-7330
Barnes, Henry, Meisenheimer & Grende
Attn: Bruce F. Barnes
4658 Gravois Avenue
St. Louis, MO 63116 USA
(314) 352-8630
Barr Engineering Company
Attn: L.W. Gubbe, Vice President
6800 France Avenue South
Minneapolis, MN 55435 USA
(612) 920-0655
Beak Consultants Incorporated
Environmental Consultants
Attn: Bruce Eddy, Fishery Biologist
Eighth Floor Loyalty Building
317 S. W. Alder
Portland, OR 97204 USA
(503) 248-9507
Bechtel National, Inc.
Attn: G.D. Coxon, Business Development
      Representative, Research Engineering
P.O. Box 3965
San Francisco, CA 94119 USA
Beling Consultants, Inc.
Attn: Tom Brennan
Beling Building
1001-16th Street
Moline, IL 61265 USA
(309) 757-9800
Benham-Holway Powergroup
Southland Financial Center
4111 South Darlington
Tulsa, OK 74135 USA
(918) 663-7622
Berger Associates
Attn: Richard H. Miller
P.O. Box 1943
Harrisburg, PA 17105 USA
(717) 763-7391
Bingham Engineering
Attn: Jay R. Bingham, President
165 Wright Brothers Drive
Salt Lake City, UT 84116 USA
(801) 532-2520
Black & Veatch
Attn: P.J. Adams, Partner
      Acting Head of Power Division
P.O. Box 8405
Kansas City, MO 64114 USA
(913) 967-2000
Boeing Engineering & Construction
P.O. Box 3707
Seattle, WA 98124 USA
(206) 773-8891
Booker Associates, Inc.
Attn: Franklin P. Eppert, Vice President
1139 Olive Street
St. Louis, MO 63101 USA
(314) 421-1476
Bookman-Edmonston Engineering
Attn: Edmond R. Bates, P.E.
600 Security Building
102 North Brand Boulevard
Glendale, CA 91203 USA
(213) 245-1883
Booz, Allen & Hamilton, Inc.
4330 East-West Highway
Bethesda, MD 20814 USA
(301) 951-2200
Bovey Engineers, Inc.
Attn: George Wallace
East 808 Sprague Avenue
Spokane, WA 99202 USA
(509) 838-4111
Boyle Engineering Corporation
Attn: D.C. Schroeder
1501 Quail Street
P.O. Box 3030
Newport Beach, CA 92663 USA
(714) 752-0505
Brown & Root, Inc.
Attn: C.W. Weber, Vice-President
4100 Clinton Drive
P.O. Box 3
Houston, TX 77001 USA
(713) 678-9009
Burgess & Niple, Ltd.
5085 Reed Road
Columbus, OH 43220 USA
(614) 459-2050
Burns & McDonnell
Attn: J.C. Hoffman
P.O. Box 173
Kansas City, MO 64141 USA
(816) 333-4375
Burns & Roe, Inc.
550 Kinderkamack Road
Oradell, NJ 07649 USA
(212) 563-7700
Lee Carter
Registered Professional Engineer
622 Belson Court
Kirkwood, MO 63122 USA
(314) 821-4091
C.E. Maguire, Inc.
Attn: K. Peter Devenis, Senior Vice President
60 First Avenue
Waltham, MA 02254 USA
(617) 890-0100
C.H. Guernsey & Company
Consulting Engineers & Architects
Attn: W.E. Pack
National Foundation West Building
3555 N.W. 58th Street
Oklahoma City, OK 73112 USA
(405) 947-5515
C.T. Male Associates, P.C.
3000 Tracy Road
Schenectady, NY 12309 USA
(518) 785-0976
CH2M Hill, Inc.
Attn: R.W. Gillette, Director of Power Generation
1500 114th Avenue, S.E.
Bellevue, WA 98004 USA
(206) 453-5000
Center 4 Engineering
Attn: Gale C. Corson, P.E.
523 South 7th Street, Suite A
P.O. Drawer A
Redmond, OR 97756 USA
(503) 548-8185
Chas. T. Main, Inc.
Attn: R.W. Kwiatkowski, Vice President
Southeast Tower
Prudential Center
Boston, MA 02199 USA
(617) 262-3200
Chasm Hydro, Inc.
Attn: John Dowd, President
Box 266
Chateaugay, NY 12920 USA
(518) 483-7701
Childs & Associates
Attn: Thomas R. Childs
1317 Commercial
Billingham, WA 98225 USA
(206) 671-0107
Clark-McGlennon Associates, Inc.
Attn: Peter Gardiner
148 State Street
Boston, MA 02109 USA
(617) 742-1580
Cleverdon, Varney & Pike, Inc.
Attn: Thomas N. St. Louis
126 High Street
Boston, MA 02110 USA
(617) 542-0438
Clinton-Anderson Engineering, Inc.
Attn: Carl V. Anderson
13616 Gamma Road, Suite 101
Dallas, TX 75234 USA
(214) 386-9191
Converse, Ward, Davis, Dixon, Inc.
Geotechnical Consultants
Attn: Kenneth B. King, Principal Engineer
The Folger Building, Suite A
101 Howard Street
San Francisco, CA 94105 USA
(415) 543-7273
Crawford, Murphy & Tilly, Inc.
Attn: Robert D. Wire
2750 West Washington Street
Springfield, IL 62702 USA
(217) 787-8050
Cullinan Engineering Co., Inc.
Attn: William S. Parker
P.O. Box 191
200 Auburn Street
Auburn, MA 01501 USA
(617) 832-5811
Curran Associates, Inc.
Attn: R.G. Curran, President
182 Main Street
Northampton, MA 01060 USA
(413) 584-7701
Dames & Moore
445 South Figueroa Street, Suite 3500
Los Angeles, CA 90071 USA
(213) 683-1560
Daverman & Associates, P.C.
Attn: Gary C. Knapp
500 South Salina
Syracuse, NY 13202 USA
(315) 471-2181
Davis Constructors & Engineers, Inc.
P.O. Box 4-2360
Anchorage, AK 99509 USA
(907) 344-0571
Dhillon Engineers, Inc.
Consulting Electrical Engineers
Attn: B.S. Dhillon, President
1600 S.W. 4th Avenue, Suite 603
Portland, OR 97201 USA
(503) 228-2877
DMJM Hilton
Attn: R.W. Baunach, P.E.
Suite 1111
421 S.W. 6th Avenue
Portland, OR 97204 USA
(503) 222-3621
Donohue & Associates, Inc.
Engineers and Architects
Attn: Stuart C. Walesh, Resources Engineering Department
Milwaukee Division
600 Larry Court
Waukesha, WI 53186 USA
(414) 784-9200
Dravo Engineers and Constructors
Attn: S. T. Maitland, Project Manager
One Oliver Plaza
Pittsburgh, PA 15222 USA
(412) 566-3000
DuBois & King, Inc.
Engineering & Environment Services
Attn: Maxine C. Neal
Route 66
Randolph, VT 05060 USA
(802) 728-3376
Ebasco Services, Inc.
Attn: R.E. Kessel, Manager of Proposal Development
2 Reactor Street
New York, NY 10006 USA
Edward C. Jordan Company
Attn: E.C. Jurick, Client Relations
P.O. Box 7050, Downtown Station
Portland, ME 04112 USA
(207) 775-5401
Eicher Associates, Inc.
Ecological & Environmental Consultants
8787 S.W. Becker Drive
Portland, OR 97223 USA
(503) 246-9709
Electrak Incorporated
Attn: R.M. Avery
6525 Belcrest Road, Suite 209
Hyattsville, Maryland 20782 USA
(301) 779-6868
Electrowatt Engineering Services
Attn: U.M. Buettner
1015 18th Street, N.W., Suite 1100
Washington, D.C. 20036 USA
(202) 659-9553
Emery & Porter, Inc.
Attn: D.B. Emery, President
3750 Wood Street
Lansing, MI 48906 USA
(517) 487-3789
Energy Research & Applications, Inc.
1301 East El Segundo Boulevard
El Segundo, CA 90245 USA
(213) 322-9302
Energy Services, Inc.
Attn: Dr. Jay F. Kunze
Two Airport Plaza, Skyline Drive
Idaho Falls, ID 83401 USA
(208) 529-3064
Energy Systems Corporation
Attn: K.E. Mayo, President
23 Temple Street
Nashua, NH 03060 USA
(603) 882-0670
Engineering & Design Associates
Attn: Stanley D. Reed
      Senior Principal
6900 Southwest Haines Road
Tigard, OR 97223 USA
(503) 639-8215
Engineering Hydraulics, Inc.
Attn: Glen Rockwell, President
320 South Sunset Street
P.O. Box 1011
Longmont, CO 80501 USA
(303) 651-2373
Engineering-Science, Inc.
Attn: G.S. Magnuson, Vice President
125 West Huntington Drive
Arcadia, CA 91006 USA
(213) 445-7560
Engineers Incorporated of Versont
Attn: Kenneth W. Pinkham, P.E.
P.O. Box 2187
South Burlington, VT 05401 USA
(802) 863-6389
Espey, Huston & Associates, Inc.
Engineering & Environmental Consultants
Attn: Sandra Hix
P.O. Box 519
Austin, TX 78767 USA
(512) 327-6847
Exe Associates - Consulting Engineers
Attn: David A. Exe
428 Park Avenue
P.O. Box 1725
Idahol Falls, ID 83401 USA
(208) 529-0491
F.A. Villela & Associates, Inc.
Civil Engineers
Attn: Frank A. Villela, President
308 Walker Avenue South
Wayzata, MN 55391 USA
(612) 475-0848
Fay, Spofford & Thorndike, Inc.
Attn: B. Campbell, Vice President
One Beacon Street
Boston, MA 02108 USA
(617) 523-8300
Fluid Energy Systems, Inc.
Attn: K.T. Miller, President/Director
2302 32nd Street, #C
Santa Monica, CA 90405 USA
(213) 450-9861
Ford, Bacon & Davis Utah, Inc.
Attn: B.G. Slighting
375 Chipeta Way
P.O. Box 8009
Salt Lake City, UT 84108 USA
(801) 583-3773
Foster-Miller Associates, Inc.
135 Second Avenue
Waltham, MA 12154 USA
(617) 890-3200
Foth & Van Dyke Associates, Inc.
2737 South Ridge Road
P.O. Box 3000
Green Bay, WI 54303 USA
Foundation Sciences, Inc.
Attn: R. Kenneth Dodds, President
1630 S.W. Morrison Street
Portland, OR 97205 USA
Frederiksen, Kamine & Associates, Inc.
Attn: Francis E. Borcalli, Associate
1900 Point West Way, Suite 270
Sacramento, CA 95815 USA
(916) 922-5481
Geo Hydro Engineers, Inc.
Attn: Leland D. Squier, President
247 Washington Avenue
Marietta, GA 30060 USA
(404) 427-5050
Geothermal Surveys, Inc.
99 Pasadena Avenue
South Pasadena, CA 91030 USA
(213) 255-4511
Gibbs & Hill, Inc.
Attn: E.F. Kenny, Director
      Planning & Development
393 Seventh Avenue
New York, NY 10001 USA
(212) 760-5279
Attn: C.A. Layland, Manager
       Government Marketing
525 Lancaster Avenue
P.O. Box 1498
Reading, PA 19603 USA
(215) 775-2600
Hall and Associates, Inc.
Attn: Ronald R. Hall, President
1515 Allumbaugh
P.O. Box 7882
Boise, ID 83707 USA
(208) 377-2780
Halliwell Associates, Inc.
589 Warren Avenue
East Providence, RI 02914 USA
(401) 438-5020
Haner, Ross & Sporseen, Inc.
Attn: J.H. Greenman
15 S.E. 82nd Drive, Suite 201
Gladstone, OR 97027 USA
(503) 657-1384
Hansa Engineering Corporation
Attn: Kurt A. Scholz, President
500 Sansome Street
San Francisco, CA 94111 USA
(415) 362-9130
Harding-Lawson Associates
P.O. Box 578
Novato, CA 94948 USA
(415) 892-0821
Mike Harper
Professional Engineer
P.O. Box 21
Peterborough, NH 03458 USA
(603) 924-7757
Harrison-Western Corporation
Attn: Eldon _rickle
1208 Quail Street
Lakewood CO 80215 USA
(303) 234-0273
Harstad Associates, Inc.
1319 Dexter Avenue North
P.O. Box 9760
Seattle, WA 98109 USA
(206) 285-1912
Harza Engineering Company
Attn: Leo A. Polivka,
      Group Management Director
150 South Wacker Drive
Chicago, IL 60606 USA
(312) 855-7000
Hoskins-Western-Sonderegger, Inc.
Attn: J.M. Carpenter, Dev. Coord.
825 "J" Street
P.O. Box 80358
Lincoln, NE 68501 USA
(402) 475-4241
Hoyle, Tanner & Associates. Inc.
Attn: H.D. Hoyle, Jr., President
One Technology Park
Londonderry, NH 03053 USA
(603) 669-5420
Hubbell, Roth & Clark, Inc. (HRC)
Environmental Consulting Engineers
Attn: George Hubbell, II
P.O. Box 824
2323 Franklin Road
Bloomfield Hills, MI 48013 USA
(313) 338-9241
Hydro Research Science
3334 Victor Court
Santa Clara, CA 95050 USA
(408) 988-1027
201 San Antonio Circle
Mountain View, CA 94040 USA
(415) 948-3919
Hydrogage, Inc.
Attn: David C. Parsons, Hydrometric Specialist
P.O. Box 22285
Tampa, FL 33623 USA
(813) 876-4006
Hydrotechnic Corporation
Attn: A.H. Danzberger, Vice President
1250 Broadway
New York, NY 10001 USA
(212) 695-6800
International Engineering Company, Inc.
180 Howard Street
San Francisco, CA 94105 USA
(415) 442-7300
J.E. Sirrine Co. of Virginia
P.O. Box 5456
Greenville, SC 29606 USA
(803) 298-6000
J.F. Sato and Associates
Attn: James F. Sato, President
6840 South University Boulevard
Littleton, CO 80122 USA
(303) 779-0667
J. Kenneth Fraser & Associates
Attn: J.K. Fraser
620 Washington Avenue
Rensselaer, NY 12144 USA
(518) 463-4408
JBF Scientific Corporation
2 Jewel Drive
Wilmington, MA 01887 USA
(617) 657-4170
James Hansen and Associates
Attn: James C. Hansen
P.O. Box 769
Springfield, VT 05156 USA
(802) 885-5785
James M. Montgomery, Consulting Engineers, Inc.
Attn: Clifford R. Forsgren, P.E.
1301 Vista Avenue
Boise, ID 83705 USA
(208) 345-5865
Jason M. Cortell & Associates, Inc.
Environmental Consultants
Attn: Susan R. Thomas, Marketing Coordinator
244 Second Avenue
Waltham, MA 02145 USA
(617) 890-3737
John David Jones & Associates, Inc.
Attn: Paul E. McNamee
5900 Roche Drive
Columbus, OH 43229 USA
(614) 436-5633
Jordan/Avent & Associates
Attn: Frederick E. Jordan, President
111 New Montgomery Street
San Francisco, CA 94105 USA
(415) 989-1025
Joseph E. Bonadiman
Attn: J.C. Bonadiman
P.O. Box 5852
606 East Mill Street
San Bernadino, CA 92412 USA
Kaiser Engineers, Inc.
Attn: C.F. Burnap, Project Development
3000 Lakeside Drive
P.O. Box 23210
Oakland, CA 94623 USA
(415) 271-4111
Kleinschmidt & Dutting
Attn: R.S. Kleinscnmidt
73 Main Street
Pittsfield, ME 04967 USA
(207) 487-3328
Klohn Leonoff Consultants, Inc.
Attn: Earl W. Speer, President
Suite 344
3000 Youngfield Street
Denver, CO 80215 USA
(303) 232-9457
Lane Construction Corporation
Attn: D.E. Wittmer, Vice President-Engineering
Box 911
Meriden, CT 06450 USA
(203) 235-3351
Lawson-Fisher Associates
Attn: John E. Fisher
525 West Washington Street
South Bend, IN 46601 USA
(219) 234-3167
Livingston Associates
Consulting Geologists, P.C.
Attn: C.R. Livingston
4002 Green Oak Drive
Atlanta, GA 30340 USA
(404) 449-8571
M L B Industries, Inc.
Attn: Thomas M. Eckert, Operations Manager
21 Bay Street
Glen Falls, NY 12801 USA
(518) 798-6814
McGoodwin, Williams & Yates, Inc.
Attn: L.C. Yates, President
909 Rolling Hills Drive
Fayetteville, AR 72701 USA
(501) 443-3404
Mead & Hunt, Inc.
2320 University Avenue
P.O. Box 5247
Madison, WI 53705 USA
(608) 233-9706
Michael Baker, Jr., Inc.
Engineers & Surveyors
Attn: Wayne D. Lasch, Project Engineer
4301 Dutch Ridge Road
Box 280
Beaver, PA 15009 USA
(412) 495-7711
Myron Anderson & Associates
Civil Consultants
Attn: Myron Anderson
16830 N.E. 9th Place
Bellevue, WA 98008 USA
(206) 747-3117
Normandeau Associates, Inc.
Environmental Consultants
Attn: Joseph C. O'Neill, Marketing Coordinator
25 Nashua Road
Bedford, NH 03102 USA
(603) 472-5191
North American Hydro, Inc.
Attn: Charles Alzberg
P.O. Box 676
Wautoma, WI 54982 USA
(414) 293-4628
O'Brien & Gere Engineers, Inc.
Justin & Courtney Division
Attn: J.J. Williams, Vice President
1617 J.F. Kennedy Boulevard
Suite 1760
Philadelphia, PA 19103 USA
(215) 564-4282
Oscar Larson & Associates
P.O. Box 3806
Eureka, CA 95501 USA
(707) 443-8381
Parsons Brinckerhoff
One Penn Plaza
New York, NY 10001 USA
(212) 239-7900
Perini Corporation
Attn: R.G. Simms, Vice President-Marketing
73 Mt. Wayte Avenue
Framingham, MA 01701 USA
Frank R. Pollock
Consulting Engineer
6367 Verde Court
Alexandria, VA 22312 USA
(703) 256-3838
PRC Engineering Consultants, Inc.
P.O. Box 3006
Englewood, CO 80155 USA
(303) 773-3788
Presnell Associates, Inc.
Attn: David G. Presnell, Jr.
200 West Broadway, Suite 804
Louisville, KY 40202 USA
(502) 587-9611
R.W. Beck & Associates
Attn: Richard Lofgren
200 Tower Building
Seattle, WA 98101 USA
(206) 622-5000
Radiation Management Corporation
Environmental Consultants
Attn: C.E. McGee, Director-Technical Marketing
3508 Market Street
Philadelphia, PA 19104 USA
(215) 243-2950
Raven Systems & Research Inc.
Environmental Consultants
Attn: John Dermody, Hydrographic Engineer
2200 Sixth Avenue, Suite 519
Seattle, WA 98121 USA
(206) 621-1126
Resource Consulting Group, Inc.
Attn: Gary Goldner, Associate
51 Brattle Street
Cambridge, MA 02138 USA
(617) 491-8315
Resource Planning Associates, Inc.
Attn: A. Ashley Rooney
44 Brattle Street
Cambridge, MA 02138 USA
(617) 661-1410
Rist-Frost Associates
Attn: Fil Fina, Jr., Partner
21 Bay Street
Glens Falls, NY 12801 USA
(603) 524-4647
Robert E. Meyer Consultants
Attn: B. Tanovan, Manager-Water Resources Department
14250 S.W. Allen Boulevard
Beaverton, OR 97005 USA
(503) 643-7531
Ross & Baruzzini, Inc.
Attn: Donald K. Ross
7912 Bonhomme Avenue
St. Louis, MO 63105 USA
(314) 725-2242
Russ Henke Associates
Attn: Russ Henke
P.O. Box 106
Elm Grove, WI 53122 USA
(414) 782-0410
Science Applications, Inc.
Attn: John A. Dracup
5 Palo Alto Square, Suite 200
Palo Alto, CA 94304 USA
(415) 493-4326
SCS Consulting Engineers, Inc,
4014 Long Beach Boulevard
Long Beach, CA 90807 USA
(213) 427-7437
Shawinigan Engineering Corporation
Attn: James H. Cross
100 Bush Street, 9th Floor
San Francisco, CA 94104 USA
(415) 433-7912
Soil Systems, Inc.
Attn: Robert L. Crisp, Jr.
525 Webb Industrial Drive
Marietta, GA 30062 USA
(404) 424-6200
Southern Engineering Co. of Georgia
Attn: J.W. Cameron
Main Office
1000 Crescent Avenue, N.E.
Atlanta, GA 30309 USA
(404) 892-7171
Spooner Engineering - North
Attn: John A. Spooner, Partner
7 Fulton Avenue
Oshkosh, WI 54901 USA
(414) 231-1188
Stanley Consultants, Inc.
Stanley Building
Muscatine, IA 52761 USA
Stone & Webster Engineering Corp.
Attn: J.N. White, Vice President
245 Summer Street
Boston, MA 02107 USA
Storch Engineers
Attn: Herbert Storch
333 East 57th Street
New York, NY 10022 USA
(212) 371-4675
STS Consultants, Ltd.
Hydraulics & Hydrology
Attn: Constantine N. Papadakis
Wolverine Tower, Suite 1014
3001 South State Street
Ann Arbor, MI 48104 USA
(313) 663-3339
Sutherland, Ricketts & Rindahl,
Consulting Engineers, Inc.
Attn: Donald D. Ricketts
2180 South Ivanhoe Street
Denver, CO 80222 USA
(303) 759-0951
Sverdrup & Parcel Associates, Inc.
Attn: D.L. Fenton, Vice President
800 North 12th Boulevard
St. Louis, MO 63101 USA
(314) 436-7600
System Control, Inc.
Attn: W.H. Winnard
1901 N. Fort Myer Drive, Suite 200
Arlington, VA 22209 USA
(703) 522-5770
Terrestial Environmental Specialists, Inc.
R.D.1, Box 388
Phoenix, NY 13135 USA
(315) 695-7228
Tetra Tech, Inc.
Attn: R.L. Notini, Engineer
630 North Rosemead Boulevard
Pasadena, CA 91107 USA
(213) 449-6400
The Kuljian Corporation
Attn: Dr. T. Mukutmoni, Vice President-Research
3624 Science Center
Philadelphia, PA 19104 USA
(215) 243-1972
(TAMS), Engineers & Architects
Attn: Eugene O'Brien, Partner
655 Third Avenue
New York, NY 10017 USA
(212) 867-1777
Tudor Engineering Company
Attn: David C. Willer
149 New Montgomery Street
San Francisco, CA 94105 USA
Turbomachines, Inc.
Attn: John W. Roda, President
17342 Eastman Street
Irvine, CA 92705 USA
United Technologies Research Center
Silver Lane
East Hartford, CT 06108 USA
(203) 565-4399
Veselka Enginering Consultants, Inc.
Attn: A. William Veselka, P.E.
325 South Mesquite Street
Arlington, TX 76010 USA
(817) 469-1671
W.A. Wahler & Associates
Attn: J.L. Marzak, Vice President
1023 Corporation Way
P.O. Box 10023
Palo Alto, CA 94303 USA
(415) 968-6250
Whitman Requardt & Associates
Attn: Henry A. Naylor, Jr.
1111 North Charles Street
Baltimore, MD 21201 USA
(301) 727-3450
Wilsey & Ham
1035 East Hillsdale Boulevard
Foster City, CA 94404 USA
(415) 349-2151
Wind & Water Power
P.O. Box 49
Harrisville, NH 03450 USA
(603) 827-3367
Woodward-Clyde Consultants
Attn: Joseph D. Bortano,
      Sr. Project Engineer
3 Embarcadero Center, Suite 700
San Francisco, CA 94111 USA
(415) 956-7070
Richard S. Woodruff
Consulting Engineer
4153 Kennesaw Drive
Birmingham, AL 35213 USA
(205) 879-8102
Wright, Pierce, Barnes & Wyman
Attn: L. Stephen Bowers, Vice President-Marketing
99 Main Street
Topsham, ME 04086 USA
(207) 725-8721
Non-U.S. Firms
Crippen Consultants
Attn: R.F. Taylor, P.E.
1605 Hamilton Avenue
North Vancouver, B.C.
Canada V7P 2L9
(604) 985-4111
Engineering & Power Deveopment Consultants, Limited
Marlowe House, Sidcup Kent, DA15 7AU
(01-300 3355)
Montreal Engineering Co., Ltd.
Attn: G.V. Echkenfelder, Vice President
P.O. Box 777, Place Bonaventure
Montreal, Quebec, Canada
H5A 1E3
Motor-Columbus Consulting Engineers
Parkstrasse 27
CH-5401 Baden, Switzerland
Shawinigan Engineering Corporation
Suite 310
33 City Centre Drive
Mississanga, Ontario, Canada
L5B 2N5
(416) 272-1300
Sogreath Consulting Engineers
47, Avenue Marie-Reynoard
38100 Grenoble, France
(76) 09.80.22
Independent Power Developers, Inc. Pelton and propeller units,
Route 3, Box 285                    company systems
Sandpoint, ID 83864 USA
The James Leffel Company            Francis/propeller/Hoppes units
Springfield, OH 45501
Associated Electric Company
54 Second Avenue
Chicopee, MA 01020 USA
(Manufacturer Representative)
Gilberg, Gilkes & Gordon, Ltd.      Wide range of turbines from
Westmorland, England LA9 7BZ        10 KW to multi-megawatt, Turgo
                                   and Kendal
Small Hydroelectric Systems         Pelton, with power range 5
P.O. Box 124                        to 25 KW for heads from 50
Custer, WA 98240 USA                to 350 feet
Cssberger Turbinenfabrik            Crossflow (Michell or Banki
D-8832 Weissenberg                  type) turbines of 1 to 1000 KW
Postfach 425
Bayern, West Germany
Westward Mouldings, Ltd.            Fiberglass water wheels
Greenhill Works, Delaware Road
Gunnislake, Cornwall, England
Campbell Water Wheel Company        Water wheels
420 South 42nd Street
Philadelphia, PA 19104 USA
Manitou Machine Works, Inc.
14 Morris Avenue
Cold Spring, NY 10516 USA
GSA Associates                      Francis units
223 Katonah Avenue
Katonah, NY 10536 USA
Niagara Water Wheels, Ltd.          Four models of propeller
706 E. Main Street                  turbines with power in range
Welland, Ontario L3B 3Y4, Canada    of 20 to 250 KW
Barber Hydraulic Turbines, Ltd.     Propeller and Francis
Barber Point, P.O. Box 340          turbines
Welland, Ontario L3B 3Y4, Canada
Canyon Industries                   Francis, miniature turbine
5346 Mosquito Lake Road             set offering 50 to 750 watts
Deming, WA 98244 USA
New Found, Inc.                     Small crossflow turbines
Route 138
Hope Valley, RI 02832 USA
Northern Water Power Company        Axial flow propeller turbines
P.O. Box 49                         with output range from 20 to
Harrisville, NH 03450 USA           250 KW
Alaska Wind and Water Power         Pelton turbines
P.O. Box G
Chigiak, AK 99567 USA
Pumps, Pipe and Power               Pelton turbines
Kingston Village
Austin, NE 89310 USA
Obermeyer Hydraulic Turbines        Crossflow and Pelton
10 Front Street                     turbines
Collinsville, CT 06020 USA
Leroy-Somer                        Siphon turbines
16 Passaic Avenue
Fairfield, NJ 07006 USA
Belle Hydroelectric                 Crossflow turbines
3 Leatherstocking Street
Cooperstown, NY 13326 USA
Maine Hydroelectric                 Belfast turbines
  Development Groups
Goose Rocks, ME 04046 USA
Allis Chalmers                      Large turbines
Hydro Turbine Division
P.O. Box 712
York, PA 17405 USA
Windworks                                  Gemini inverter
Box 329, Route 3
Mukwonago, WI 53149 USA
Lima Electric Company, Inc.                AC alternator
200 East Chapman Road
Box 918
Lima, OH 45802
Woodward Governor Company                  Mechanical governor
5001 N. 2nd Street
Rockford, IL 61101 USA
Natural Power, Inc.                       Governor
New Boston, NH 03070 USA