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A Guide to
Understanding and Constructing Your Own Small
Hydro Project
Indroduction
CHAPTER
#1 -ENERGY FROM WATER - IS YOUR PROJECT WORTH PERSUING?
CHAPTER #2 - SITE EXPLORATION AND STREAMFLOW DATA
CHAPTER #3 - ASSESSMENT OF THE FEASABILITY OF YOUR HYDRO SITE
CHAPTER #4 - CIVIL WORKS AND EQUIPMENT
CHAPTER #5 - PERMITS, LICENSES AND LEGAL ASPECTS FOR SMALL HYDRO
CHAPTER #6 - ECONOMICS AND FINANCING
CHAPTER #7 - GETTING STARTED
CHAPTER #8 - LOW HEAD CONSIDERATIONS
CHAPTER #9 - COLD WEATHER CONSIDERATIONS
CHAPTER #10 - ORGANIZATION AND OPERATION OF A PUBLIC UTILITY
GLOSSARY
INTRODUCTION (Chapter 1
Index)
Why Small Hydro
British Columbia offers enormous small hydro potential to its
inhabitants: about 2400 MW, with 550 sites near the grid. Small Hydro is
part of the history of British Columbia. Many early mills, mines and towns
built some form of power generation from small hydro, in the late 19th and
early 20th centuries; and waterwheels were used much earlier - in
Ashcroft, in 1863, for example. Most of these old sites have fallen into
disuse by now - rendered uneconomic in the 1950's by the availability of
cheaper electricity through an expanding, province-wide grid; and by the
availability of portable, flexible, low cost diesel generators. Diesel
generators are still cheap to buy - but the rise in the cost of oil has
made them expensive to operate. And the provinces electrical grid, while
extensive, does not include a number of small communities, resource-based
businesses, farmers, and lodge owners: people in out of the way locations
who are paying an enormous cost for their independent way of life. Such
people are taking another look at water power, because it offers a stable,
inflation-proof source of electricity, using proven technology. Small
hydro installations have, historically, been cheap to run but expensive to
build. That is changing now, with smaller, lighter, and higher speed
turbine equipment, lower cost electronic speed and load control systems,
and inexpensive plastic piping. Capital investments are still higher than
investing in diesel equipment of comparable capacity; but the long life
and low operating costs of small hydro make it an attractive investment
for many applications. Examples of such installations, built in B.C.
during the past few years, include: Glacier Park (150 kW); Hoeya Hilton
(37 kW); Nimmo Bay (40 kW); Hasty Creek (37 kW); Klemtu (650 kW); Kingcome
(75 kW); and Rendell Creek Ranch. Some very small, and very successful
units have been installed by entrepreneurs - a farmer in the Pemberton
Valley, for example (25 kW). other, larger units, have been build by
entrepreneurs who then sell power on contract to a resource industry -
Lancaster Resources (now Synex) at Moses Inlet, selling to Crown Lumber.
There are business opportunities in small hydro - and a number of people
are catching on.
Purpose of the Manual
This book is written to assist people who are interested in developing
a small hydro opportunity. It will be especially useful to people with
small sites that would not justify the expense of extensive professional
engineering services. Even with small sites, such services may be
advisable if you have conditions you do not fully understand. The book
will provide you with the information you need to: - evaluate the
potential of a small hydro site; - lay out the site; - apply for necessary
licences and permits; - get financing; - select and install equipment and
- understand the equipment, so that you can operate and maintain the
system yourself. The emphasis in the book is on doing as much as possible
yourself, thus keeping capital costs as low as possible. However, advice
on seeking professional help is also included - and the information
contained in these chapters will be invaluable to you in dealing with any
consultants and contractors you hire. Actual construction details are not
included; general guidelines are given, along with pointers on what help
can be expected from a construction contractor. The book does not assume
any previous acquaintance with the subject. mathematical procedures are
generally limited to multiplication and division for the fundamentals.
(more sophisticated procedures may yield greater accuracy, but the simpler
procedures outlined here should be sufficient for the scope of projects
intended.) A hydro turbine generator can by very small, like the
alternator for a car (c. 500 Watts); or it can be very large, like the
units at the Revelstoke Dam (several thousands of millions of Watts).
microhydro (1-100 kW) and mini-hydro plants (100 kW to 5 MW) are the
smallest of the turbine generator units. This handbook is aimed mainly at
installations of less than 500 kW, although it covers licensing
requirements up to 20 mw. The writers of the chapters that follow are all
experts in their fields, and have all written as clearly and simply as
possible. It will take time and study, however, to thoroughly understand
each section of the book especially the charts, tables, and graphs. The
effort will pay off: your chances of bringing a project to a successful
completion, producing reliable energy year after year, and significantly
improving your cash flow, will be greatly enhanced.
Cost of Development
Costs for smally hydro installations vary considerably, because sites,
conditions and sizes are all different. In 1985, the typical development
can range from $1,500 to $5,000 per installed kW. This would mean an
investment of from $6,000 to $20,000 for the "typical" simple family home,
which requires a peak demand of 5 kW. (If that home were using electric
heating, the demand would be from 12-20 kW.) This handbook shows how to
estimate installation cost, and how to balance design tradeoffs, cost, and
projected energy production. You can significantly reduce costs by clever
management, procurement, and hard work. The system at Rendell Creek Ranch
cost only $25,000 for a 150 kW system - less than $200 per kW - because
the community did most of the work itself and was able to buy and rebuild
used equipment. In approaching costs, remember that there are two basic
types of developers: those who are interested in generating to meet only
their own needs, regardless of the site's potential; and those who want to
get as much as possible out of the site. Costs for the former developer
will generally be lower because the system will be smaller, and geared
both to minimum requirements and minimum flow. Investment for the latter
will be higher, but the per kW cost may be less.
Organization of the Manual
You are encouraged to peruse the book and gain a general knowledge of
its contents before starting actual development. Chapters One, Two and
Three represent the major steps for any site development. Chapter Four
then treats dams, intakes, penstock, turbines and all equipment associated
with the manufacture of a small hydro site, in considerable detail.
Chapter Five serves as a guide to developers on the legal aspects of
permits, licences and insurance. This is a weighty section, but an
understanding of the requirements is essential. Chapter Six, on Economics
and Financing, takes you through the economic feasibility of the project
and helps you decide on the economics of the project. Chapter Seven is
subtitled "Getting Started". It gives the developer some practical tips on
the many logistical steps necessary to carry through with the project,
once it is designed. It will help get the project started and help you
make sure it is completed. Chapters Eight and Nine are specialized
chapters on Low Head and Cold Weather Considerations. If you are working
under either of these constraints, these chapters should be read
carefully. Chapter 10 outlines the requirements for setting up a utility,
should you wish to sell your surplus power.
CHAPTER #1 - ENERGY FROM WATER - IS YOUR PROJECT WORTH
PERSUING?
1.1 ..........Introduction
1.2 ..........Your Power
Requirements
1.3 ..........Power and Energy
Definitions
1.4 ..........Data Collection
1.5 ..........Installations
1.6 ..........Available Power and
Energy
1.7 ..........Advisors
1.8 ..........Project Costs
1.9 ..........Project Worth
1.10 ..........Continued
Planning
1.11 ..........Project Data
Summary
SUPPLEMENT / MEASURING HEAD AND STREAMFLOW / PRELIMINARY
1.1 ..........Introduction (Back)
Perhaps you are living close to a stream and you are considering
building a small hydro project on it. Or perhaps you are starting to plan
a project and you are looking for a suitable stream. In either case this
chapter will help you. Chapter One covers: (a) The fundamentals of
providing electrical energy from water; (b) the process of selecting a
suitable stream and a site for a hydro project; (c) the simple
calculations for helping you to decide whether you should continue
planning your project, or whether you should start looking for some other
way of getting electricity; and (d) the costs, procedures and time
requirements of hiring an engineer to do the preliminary work. Probably
your most valuable experience is to have lived next to a stream for
several years and to have noted the fluctuations in its flow: how high and
low it can go, how soon it reacts to a rainstorm, and how the stream
changes its course when in flood. However, without this background
knowledge you will still be able to build a good hydro project. To help
you decide whether or not to continue with your the project, you will be
asked to (a) estimate the power you need; (b) estimate the streamflow
available; (c) measure or estimate the head available on the stream; (d)
estimate the power and energy available from the stream; (e) make a
preliminary layout of your project; (f) make a preliminary estimate of the
cost of your project; and (g) decide: "Is your project worth pursuing?"
Each time you make an estimate or calculation, you should enter it in
Table 1.3, "Project Data Summary" at the end of this chapter. If you have
already decided to continue planning, you should still skim through this
Chapter and check that you have the data listed under all the headings in
Table 1.3.
1.2 ..........Your Power Requirements (Back)
First, you need to estimate how much power and energy you use at
present, and how much you will use, say, ten years from now. Normally some
degree of load management is used in mini-hydro plants. The loads shown in
Table 1.1 assume some degree of load management.
1.2.2 Load Estimates
An approximate estimate of the load will do at this stage. A more
accurate estimate will be made in Chapter 3. Using Table 1.1 to estimate
your peak winter and summer loads, select a value within the ranges given.
These ranges indicate the difference in loads due to different living
styles and different climates. Take account of the appliances you have,
compared to those listed in the table, and the conservation or
extravagance in your use of electricity. Also consider the climate where
you live: you will use more electricity in the interior and northern parts
of B.C. than you will on the coast, on Vancouver Island, or in the Lower
Mainland. Following the example below, write down your expected future
peak load value for the winter (November-April) and summer (July-October).
Use a future of 10 years time or whatever time span you wish to consider
for the hydro plant. If you want to make a more detailed estimate, turn to
the section on "Power and Energy Requirements" in Chapter 3. Do this only
if you want to learn more about load management: it gets quite
complicated. Example: A single family house with 2 bedrooms and workshop -
electric lights, washer, drier, fridge, freezer, kitchen appliances (no
oil, propane or wood cooking stove), baseboard and hot water heating,
table saw, small hand tools. From Table 1.1: (In this example case 3B, a 3
bedroom house without back-up for heating, is used to allow for additions
in the future.) Example Your Expected Loads Winter Maximum Load 12 kW
................ kW Summer Maximum Load 5 kW ................ kW (Write
these values at the top of Table 1.3)
1.2.3 Energy Conservation
Do you conserve energy as much as you can? Have you considered the
following ways of reducing your energy consumption, and thereby reducing
your costs? - upgrading insulation in basements, floors, walls, cedilings
and attic; - adding storm windows or double or triple glazing; - reducing
air leaks by caulking and weatherstripping round dorrs and windows; -
servicing the oil or propane furnace and water heater; - insulating the
hot water tank and pipes;
1.3 ..........Power and Energy Definitions (Back)
The methods for calculating power and energy that are available from a
stream are covered in this section.
1.3.1 ..........Power
The calculation of the actual power from your stream is covered in
Section 1.6, after you have measured or estimated the flow and head. The
theoretical power equation (Equation 1-1) is P= Q x H x e x 9.81 Kilowatts
(kW) (1-1) Where: P = Power at the generator terminal, in kilowatts (kW).
Q = Flow in pipeline, in cubic metres per second (m3/s). H = The gross
head from the pipeline intake to the tailwater, in metres (m) (see Figure
1.2). e = The efficiency of the plant, considering head loss in the
pipeline and the efficiency of the turbine and generator, expressed by a
decimal (ie 85% efficiency 0.85) 9.81 = Constant for converting flow and
head to kilowatts. All power systems produce less power than is
theoretically available. The losses in a hydro plant are: (a) losses in
energy caused by flow disturbances at the intake to the pipeline, friction
in the pipeline, and further flow disturbances at valves and bends; and
(b) losses of power caused by friction and design inefficiencies in the
turbine and generator. The energy losses in the pipeline and at valves and
bends, are called head losses: they represent the difference between the
gross head and the net head that is available at the turbine (see Figure
1.2). The head losses in the pipeline could range from 5 percent to 15
percent of the gross head, . depending on the length of the pipeline and
the velocity of the flow. The maximum turbine efficiency could range from
80 percent to 90 percent depending on the type of turbine, and the
generator efficiency will be about 90 percent. At this stage in the
planning of your hydro plant, the head losses can be combined with the
losses in the tubine and generator, and an overall plant efficiency of 60
percent (or e = 0.60) can be used. Using e = 0.60 in Equation 1-1, the
actual power output at the generator can be calculated from the following
Equation 1-2: P x H x 5.9 (kW) (1-2) The Power Output Nomograph in Figure
1.3 enables you to make quick estimates of power, flow or head. Example:
Suppose you know the lowest flow (discharge) in the stream (say 0.1 M3/s
or 100 L/s), and you know where to put the intake and powerhouse so you
can estimate the head (say 10 m). Example Your Values Flow 100 L/s L/s
Head 10 m M In Figure 1.3 mark a point (in pencil) at a flow of 100 L/s on
the DISCHARGE (left) scale; on the HEAD (right) scale mark a point at a
head of 10 m. Draw a straight line between the two points and where this
line intersects the POWER (middle) scale is the estimated power, in this
case 5.9 kW. Power 5:9 kw' kW If you have been using your own values of
flow and head, and find that the power output is not enough for your power
requirements, don't worry: you're just trying out the nomograph. Later in
this chapter you will make the proper calculations. Other ways of using
the nomograph are: (a) to find the necessary flow, provided you know your
power requirements and can estimate the head available on the stream.
Extend a straight line from the HEAD scale through the POWER output scale
and onto the DISCHARGE scale, or, (b) to find the necessary head, provided
you know your power requirements and can estimate the minimum flow in the
stream. 1-6 1.3.2 Energy The equation to calculate energy is E = P x time
Where: E = Energy, in kilowatt - hours (kW.h) P = Power, in kilowatts kW
Time = Time while power is generated or used Example: If you run a 1000
watt (1 kW) electric heater for 5 hours you use 5 kW.h of energy.
1.4 ..........Data Collection (Back)
Streamflow, head and pipeline length must be estimated or measured,
before you can calculate the power that could be developed from a stream.
Streamflow is the most difficult to measure or estimate. However you
should have an understanding of its sources, its fluctuations and flow
measurements or estimates.
1.4.1 Streamflow
Streamflow comes from either rain or melting snow, but not all the rain
or melting snow immediately becomes streamflow. There are losses caused by
evaporation from the ground surface, transpiration by the vegetation whose
roots have absorbed moisture from the ground and from seepage or surface
water into the ground to become groundwater. This groundwater can take
weeks or months to appear as streamflow, and is therefore not available
for power immediately after rain or snowmelt. However, this groundwater is
important, the major component of the streamflow during dry periods in the
summer or winter. A hydro project should be designed for these dry, low
flow periods. It is advised that you check both Fisheries and Water
Licenses statutes of the creek prior to doing much work, it might belong
to someone else.
Streamflow Fluctuations
We all know that streamflow fluctuates, often daily, always seasonally
and yearly. To visualise these fluctuations, values of flow are plotted
against time, as shown on Figure 1.4 (A and B) these plots are called
hydrographs. In Figures 1.4.A and 1.4B, hydrographs of flows in 1980 are
shown for six rivers in five different parts of B.C. Notice the different
patterns of flow in different parts of the province. The simplest pattern
is for Beatton Creek in southeast Interior (Figure 1.4A): (a) low flows in
January to March (cold weather). (b) rapidly increasing flows in April
(snowmelt). (c) high, erratic flows in May and June (snowmelt plus rain).
steadily decreasing flows in July and August (no further snowmelt). (d)
low flows again through the winter. Brouse Creek (Figure 1.4A), in the
same area as Beatton Creek, is much smaller. The pattern for these two
creeks is similar except that in Brouse Creek the major snowmelt period is
in May only. Moving westward to the Coquihala River (Figure 1.4A), the
effect of winter rain is reflected in the extremely sharp peaks in
December. A pronounced snowmelt period lasted from April until June, and
prolonged low flow periods occurred in January and February and again
between August and October. In the North, the Cottonwood River hydrograph
(Figure 1.4B) shows the prolonged low flows caused by low temperatures
from December through to the end of April. West of the Coast Mountains,
the Little Wedeene River hydrograph (Figure 1.4B) shows the effect of
heavy rain from September to December. The snowmelt period, April to June
is not so obvious because of the erratic rain peaks superimposed. Short
periods of low flows occurred in most months January - March and August -
October. In the Northern part of Vancouver Island, the pattern of flows
for the Ucona River is less distinct; erratic flows during the winter
(rain and snowmelt), fairly steady flows April - June (snowmelt), then
decreasing flows to September (little rain). Knowing these patterns will
help you choose the right time of year to measure low flows and average
flows. You will also recognize the relation between low, average and high
flows; this will enable you to check the magnitude of your measurements or
estimates.
Streamflow Measurements and Estimates While many larger streams and
rivers in B.C. have gauges installed by Federal or Provincial Government
agencies, it is unlikely that there will be a gauge on your stream. You
will probably have to measure or estimate the flow. There are several ways
to measure flow: 1-8 (a) use a float to measure velocity and a level and
tape to measure the stream cross-section, (b) construct a weir (A weir is
a low dam over which the water flows) across the stream and measure water
levels or, (c) use a flow-meter to measure velocity, and a level and tape
to measure the stream cross-section. using a float is the easiest but the
least accurate method. Building a weir or using a flow-meter are the best
methods for establishing a semi-permanent measuring station to obtain
flows for several months or years. At this stage in the planning process,
you should use the float method described in Supplement 1 . 1 (at end of
this chapter). What flows should be measured? This will depend on the
amount of water the hydro plant will take from the stream compared to the
minimum flow in the stream. You need to get an overall picture of the
variations in the flow of the stream. But the lowest flow is usually the
most important because it can limit the maximum power that can be
produced. At this stage, you don't know how much flow the hydro plant will
take. But it is helpful, when deciding what stream flow to measure, to
keep in mind three situations: 1. The stream is large and only a small
portion of the lowest f low is needed for your hydro plant. If you know
that you will always have enough water for the plant. You don't have to
measure the flow; you can go onto the next section on "Head", however, if
in doubt at all measure the flow. Streamflow is difficult to eyeball. 2.
The minimum flow in the stream is about equal to or is slightly more than
the flow needed to produce maximum power. You should measure the lowest
flow, then estimate the minimum flow that can be expected in the stream:
this is explained later. 3. The minimum flow in the stream is less than
the flow needed to produce maximum power, and water will have to be stored
for part of the year (water storage is discussed in Section 1.6.3), or a
diesel generator will have to be used when the flow is low. In this case,
you need to know the low and average flows. You should measure the lowest
flow you can and also the average flow, several times. If the stream dries
in the summer or winter, measure the lowest flow about one month before it
normally dries. Measure the flow when it is low and/or average, according
to the three guidelines above. Make several measurements on different
days.
1.5........ INSTALLATIONS (Back)
This is the time to decide on a preliminary arrangement for your hydro
project: The locations of the intake, dam, pipeline and powerhouse: and
the type of turbine needed. If possible, get a map of the area from a
government office, a local logging company or a forester with the Ministry
of Forests maps, and where to get them are discussed in Supplement 2.1 at
the end of Chapter 3). Draw on the map the intake, dam, pipeline,
powerhouse, and transmission line. This will help you define the layout
and help you describe the project to someone else, such as a small hydro
owner, a bank manager, a person in the Water Rights Branch office:
To help you decide on a layout, the following
considerations will be covered in this section:
(a) run-of-river versus storage projects;
(b) typical project layouts;
(c) project structures ie. dam, weir, intake,
canal, pipeline, powerhouse, tailrace,-
(d) to suitable turbines (Cross-flow, Francis and
Pelton turbines) for love, medium and high head projects;
(e) existing dams and;
(f) transmission
lines.
1.5.1 Run-of-River versus Storage Projects
A run-of-river project is built to use some or most of
the flow in a stream depending upon the flow throughout the year. No
attempt is made to store water for the dry periods. A run-of-river project
would not normally have a dam, other than an intake weir, which is a very
low structure at the intake. The intake weir keeps the water in the stream
high enough to fill the pipe at all times.
A storage project on the other hand, has a dam, which
creates a water storage reservoir to maintain flow in the stream during
low flow periods. The intake to the pipeline might be part of the dam or
separate from it, depending on the location of the pipeline.
1.5.2 Project Layouts
The layouts shown in Figure 1.5 are typical of most
projects that would be built in B.C.
Layout #1 is the simplest, with a weir or low dam
across the stream, an intake to the pipeline, the pipeline, powerhouse
and tailrace channel (each structure is described in more detail in
Section 1.5.3). The weir forms a pond to ensure that there is always
water above the pipe at the intake; the pipeline carries the water,
under pressure, to the turbine in the powerhouse; the tailrace channel
carries the water from the turbine back into the stream, or into a lake
or the sea.
Layout #2 illustrates a possible cost-saving
arrangement, whereby a canal or low-pressure pipeline is built to
contour around a hillside, and a shorter high-pressure pipeline, called
a penstock, is used.
Layout #3 shows a pipeline intake incorporated in a
storage dam.
Layout #4 shows a situation where there is a lake
suitable for a storage reservoir some way up the stream. A dam can be
built at the lake to store water, which can be released down the stream
during dry periods.
Layout #5 and Layout #6 show the layout of a low
head plant where there is less than 10 m gross head. Notice that there
is no pipeline or dam. Layout #5 shows the weir, intake and powerhouse
combined into one structure. Layout #6 shows a power canal between the
intake and powerhouse.
Many aspects of a low head plant are different from those
of a higher head plant (head greater than 20 m): flows are higher, the
turbine is larger, no pipeline is used. For these reasons low head plants
are discussed separately in Chapter 8.
1.5.3 Structures
The structures of a hydro project are described in detail
in this section. Guidelines for selecting sites for these structures are
given in Chapter 2, Section 2.6. Suggestions are given below for
estimating dimensions for some of the structures. This will enable you, in
Section 1.8.1, to estimate the cost of your project.
Storage Dam
A storage dam, normally 3 m to 10 m high and constructed
of earth or rock, should be designed by an engineer.
There are many different designs for earth and rock dams.
A typical earth-fill dam, as shown in Figure 1.6, has a central section
constructed of low permeable material supported on either side by higher
permeable material. The material has to be carefully compacted in thin
layers as it is built.
The pipe through the dam could continue to the turbine,
or could discharge into the stream or a canal at the downstream side of
the dam. There would be a valve at the upstream end of the pipe.
A spillway would be built into the dam to allow high
flows to pass without overtopping the dam. The crest of the spillway would
be lower than the top of the dam.
Intake Weir
Normally you would need to build a low weir (1 m to 2 m
high) across the stream at the intake to the pipeline, to form a headpond
(see Figure 1.6). This headpond would:
(a) ensure a high enough water level to keep water
always above the top of the pipe.
(b) allow some of the sediment in the stream to
settle out before entering the sediment trap,
(c) allow an ice sheet to form, giving some
protection against water freezing in the pipeline, and
(d) provide pondage (water storage) to compensate for
one or two-day water shortages.
Water would flow over the weir most of the time.
While there are many ways to build a weir, concrete,
rock-filled gabion and rockfilled timber-crib structures are the most
common for small hydro projects (see Figure 1.6).
If the weir is built across a narrow part of the stream
and founded on bedrock, a concrete structure would probably be the most
economical. In other cases a concrete structure would probably be the most
expensive, but it would also last the longest without maintenance.
A gabion is a wire-mesh box filled with rock. Assuming
there is a good supply of rock at the site, only the wire-mesh need be
bought and transported to the site. Gabions are not waterproof, so an
impervious polyethylene membrane or asphalt sheeting would be laid on the
upstream side. Fill would be placed on the upstream side to protect the
membrane. A reinforced concrete cap should be placed on the top of the
gabions to protect them from the water and debris passing over the
weir.
A rock-filled timber-crib dam is often the least costly
weir to build, especially if rock is,available at the site and timber can
be cut nearby.- Timber or logs are placed in alternate directions and
spiked where they cross (see Figure 1.6). The bottom logs should be
anchored to the foundations, and the space between the logs should be
filled with rock. Wooden sheathing is attached to the upstream face and
the crest, and often sheathing is also placed on the downstream face. Low
permeability fill should be placed upstream to reduce seepage through the
dam and foundations.
Water in the headpond must be kept at a certain height
(called submergence) above the top of the pipe, to prevent air entering
the pipe. Values of submergence are given below:
Pipe Diameter Submergence
less than 600 mm = 1.0 m
600 - 1200 mm = 1.5 m
(Pipe diameter is discussed in detail in the "Pipeline"
section, which follows.)
The crest of the weir should be above the top of the pipe
by an amount equal to 0.5 m plus submergence.
Intake
The intake to the pipeline can be a separate structure,
part of the intake weir, or part of the storage dam. There are many types
of intake. The sketch in Figure 1.6 shows the components of a typical
intake.
To prevent sediment from flowing into the turbine, a
sediment trap can be built upstream of the intake structure or within the
structure; or immediately downstream, as a separate self-flushing tank
built into the pipe.
A trashrack prevents floating debris from entering the
pipe. Trashracks must be cleaned regularly.
Stop-logs or a valve should be provided to shut off the
flow from the pipeline during maintenance or repair of the pipe, or
closure of the turbine during cold weather. An air vent should be placed
just downstream of the valve to prevent the pipeline collapsing when it is
emptied with the valve closed.
The top of the intake should be at least 0.5 m below the
top of the weir.
Pipeline
To help you determine the preliminary arrangement and
cost estimate of your project, you also need to decide on pipe diameter,
pipe material, above-ground or underground pipe location, pipe support and
anchore blocks.
You need to know the diameter of the pipeline to estimate
its cost in Section 1.8.1. The diameter can be read from the graph in
Figure 1.7, by using your value of Qmin (from Section 1.4.1, or from Table
1.3) on the horizontal axis, then reading the diameter on the vertical
axis.
Example: Your Values
pipe flow =Qmin.....................................200
L/s ...................................L/s
or 0.20 m3/s ....................................M3/s
Pipe Diameter D................................... 410 mm
.........................mm
Write your value of pipe diameter in Table 1.3 for later
reference.
Steel, cast iron, aluminum, polyethylene and PVC are
materials used for small hydro pipelines and penstocks. Generally, for the
higher head sites in B.C. (above 20 m head) polyethylene or PVC are used.
When the head is greater than about 60 m, use of steel at the lower end
(higher head) of the pipeline is more economical.
PVC pipe should be buried for protection from the sun's
ultraviolet rays and polyethylene and cast iron pipes should be buried for
potection against damage from falling trees or rocks, or from logging
machinery. If air temperatures normally stay below -5C for more than five
days at a time, the pipeline should be buried or insulated.
Supports must be provided for rigid pipes such as steel,
cast iron, or aluminum, but the more flexible polyethylene can be laid
directly on the ground or on wooden supports. Anchor blocks should be
placed around the bends of all types of pipes. A thrust block should be
built at the lower end of the pipeline, just upstream of the
powerhouse.
Powerhouse
The size of the powerhouse is determined by the type and
size of the turbine installed. Figure 1.6 shows typical layouts for Pelton
and Francis turbines. A low head plant (less than 10 m head) looks
quite different: See Chapter 5 for details.
The substructure -- which consists of the pedestal of the
turbine and generator, the draft-tube or discharge pit, and the floor slab
- should be made of concrete. The superstructure -which is above the floor
and protects the machinery and electrical controls from rain, heat, cold
and vandalism -- can be made of wood frame, metal frame, concrete block,
log or self supporting metal panels. Make sure that the superstructure
allows the turbine and generator to be installed and removed for
repair.
Tailrace
The tailrace is a channel which leads the water from the
turbine back into the stream, a lake or the sea. It should prevent the
water from damaging any structure or the landscape.
1.5.4 Low, Medium and High Head
Low, medium and high head are terms used to indicate the most suitable
type of turbine for the project. The various types of turbines listed in
the table below are described in Section 4, "Turbines".
- Low Head up to 10 m Use: Cross-flow, axial-flow or propeller
turbine
- Medium Head 10 m to 200 m Use: Cross-flow, Francis, Pelton or Turgo
turbine
- High Head 200 m to 1000 m Use: Pelton, Turgo-impulse or Francis
turbine
1.5.5 Existing Dams
If there is already a dam on a stream nearby, you should consider using
it. First, find out who owns it, then try to assess what repairs would
have to be done if you were to use it as an intake dam or a small storage
dam. Could you incorporate in the dam an intake for a pipeline? You should
have an engineer check the dam before further developing your plans for
its use. You should also check with Water Management Branch as a changed
use could require the dam to be upgraded.
1.5.6 Transmission Line
If your load (i.e. house, bunkhouse, sawmill, etc.) is more than 100 m
from your powerhouse, you will need a transmission line, and probably
step-up and step-down transformers. Transmission lines are expensive
($17,000/km or more) so always plan to put the powerhouse as close as
possible to your load; however, they are less expensive than pipelines so
a trade off must be made.
1.6....... AVAILABLE POWER AND ENERGY (Back)
Now that you have measured, or estimated, the lowest
expected flow (Qmin) and gross head (Hg), you can calculate the power and
energy available from the stream. To calculate power, use the nomograph in
Figure 1.3, or the power Equation 1-3, as explained in Section
1.6.1. The calculation of energy is explained in Section
1.6.4.
1.6.1 Firm Power
Firm Power is the power that is always available from the stream, even
at times of lowest flow and lowest head. To calculate firm power you use
the lowest expected flow in the stream (Qmin) and the gross head (Hg). In
the case of a low head plant (less than about 10 m) in which the forebay
level varies, the gross head should be measured to the minimum forebay
level.
Using these new symbols for Q and H, the power equation (1-2)
becomes: FIRM POWER (Pfirm) = Qmin x Hg
x 5.9 kW (1-3)
Remember, in this equation, the overall plant
efficiency is assumed to be 60 percent because of head loss in the
pipeline, and turbine and generator efficiencies. The nomograph in
Figure 1.3 was drawn from this equation.
With the values of Qmin and Hg that you have written
into Table 1.3, use the nomograph in Figure 1.3 to calculate the firm
power Pfirm.
Example:
Example Your Values
On the nomograph enter:
Qmin 200 1/s 1/8
Hg 30 m m
From the nomograph:
Pfirm 35 kW kW
Write your Pfirm value - the firm power available from
the stream into Table 1.3.
1.6.2 Design Capacity of Hydro Plant
The design capacity (or installed capacity) of your
hydro plant is the maximum power it can produce. For this stage in the
planning process, assume that the design capacity is made equal to the
maximum load, using some load management, as discussed in section 1.2.2.
Also, assume that the plant can produce maximum output -equal to the
maximum controlled load -- when the flow in the stream is at its lowest.
This means that the plant will be able to produce all the power you need,
even during dry periods.
These assumptions are summarized:
Design capacity of plant (kW) = Maximum load (kW) =
Firm power (kW)
This is a simplifying assumption that is satisfactory
for the calculations in Chapter 1, a more detailed analysis is made in
later chapters.
1.6.3 Storage Reservoir
If your hydro plant cannot produce enough power to meet
your peak load when the streamflow is low, you can:
(a) build a dam and create a storage reservoir,
or
(b) Use a diesel generator or other source of power
during low flow periods.
The stream might dry up completely in the summer or in
the winter after several weeks of very cold weather. Even with a storage
reservoir or an alternative source of power for these short no-flow
periods, a hydro project might still be economic.
Decide if you want to build a storage dam or use an
alternative source of power. If you already have a diesel generator, you
might choose to use that. If there is a lake upstream of your planned
pipeline intake, you might choose to build a small dam at the outlet of
the lake to control storage.
You do not have enough information yet to calculate the
volume of storage you require, or the height of the dam. How to calculate
these is described in Chapter 3. Until then, if you plan to build a dam,
follow the guidelines in Section 1.8.1 for including an allowance for the
cost of the dam.
1.6.4 Energy
Next, estimate the average annual energy that you will
use from your hydro plant. You will need this in Section 1.8.2 to estimate
your hydro energy cost (cents/kW.h). By comparing this cost with the cost
of alternative sources of energy, such as a diesel generator or energy
from a B.C. Hydro power line, you can decide if you wish to build the
hydro project.
The amount of energy that you will use from your hydro
plant will depend on:
(a) the design capacity of the plant, compared to the
flow and head available in the stream, and
(b) the variations in your load (discussed in Section
1.2.1).
For each plant and stream, there is a specific set of
conditions which has to be known before you can calculate accurately
the average annual energy output.
At this stage you do not have enough data, and
simplifications must be made.
If you wanted to generate constant power equal to
your maximum load (assuming some degree of load management), the
annual energy output would be:
B (annual) = Pdesign x 8760 kW.h (1-4)
Where:
E (annual) = Annual energy output (kW.h).
Pdesign = Firm power (kW) calculated in Section
1.6.1. 8760 = Number of hours in a
year.
However, your load will not be constant (as discussed in
Section 1.2.1) and the design capacity of the plant (Pdesign) would
probably be larger than your maximum load, to include the possibility of
increased loads in the future. You will also have to shut down the plant
for maintenance. For these reasons, your actual annual energy output will
be less than indicated by Equation (1-4). To account for this, a Plant
Factor (or Capacity Factor) is used:
Plant Factor (PF) Average power generated during
year Plant design capacity (Pdesign)
The average annual energy output would then be:
E (annual) = Pdesign x PF x 8760 kWh
(1-5)
Plant factors describe the way in which a plant
operates over a period of time, say, for several years.
For these preliminary estimates of average annual
energy, use a plant factor of 80 percent. (A plant factor of 80
percent applies to a system with automatic load management. If you do
not intend to use automatic load management, use a plant factor of 50
percent.)
Average annual energy is:
E (annual) = Pdesign x 0.8 x 8760 (1-6)
= Pdesign x 7000
kw.h
Example:
In the previous examples in Section 1.6.1 we
calculated the Firm Power output of a stream to be 35 kW. Assume
that the plant is designed to produce maximum power equal to this
Firm Power from the stream.
Using Equation (1-6), the average annual energy
used is:
E (annual) = 35 x 7000 kW.h
= 245,000
kW.h
1.7....... ADVISORS (Back)
Turbine manufacturers, pipe suppliers, contractors and
electricians will give you free advice. owners of small hydro plants,
particularly those who have built their own, will usually be pleased to
tell you about their experiences and offer advice.
1.7.1 Engineers
You can hire an engineer to do part or all of the design
of the project. An engineer can
(a) advise on specific problems such as, safety of
the existing dam you might want to use; foundations for a dam,
pipeline supports or powerhouse; type of electrical or mechanical
equipment;
(b) design certain structures such as a dam, pipeline
supports, an electrical load control panel, or a turbine;
(c) make a preliminary study to confirm the
feasibility of the project;
(d) prepare a feasibility report for a bank or
investor from whom you want to borrow money; or
(e) design and supervise the construction of the
project.
Guidelines on the cost of these services are given in
Section 1.8.1, "Engineering Costs".
Before you hire an engineer, contractor or any other
professional person, ask for an estimate of the cost of services and
expenses to be paid. Ask him to write down exactly what he will do and
how long it will take. Make sure you understand what he said he would
do, and that this is what you want. When he's finished the job and you
want him to do more, or he suggests doing more, again, ask for an
estimate on the additional work. In that way you are in control of
your expenses and you will avoid unpleasant surprises when you receive
his bill.
The decision to hire an engineer is yours, but there
are typical situations under which you are advised to hire an
engineer:
(a) Dam Design: If you need to build a storage dam,
or if your intake dam is more than 1.5 metres high, an engineer
should check the design and the foundations.
(b) Existing Dam: If you plan to use an existing
dam to store water, an engineer should check the safety of the
dam.
(c) Pipeline: If the head is greater than 30 m; if
the length is longer than 300 m; or if the diameter is larger than
0.5 m an engineer should review your design for waterhammer, pipe
strength, pipe supports and anchors. These limits are abribtrary and
may not apply to all sites.
(d) Excavations: If you have to excavate into a
steep or unstable looking side slope for an access road, pipeline or
the powerhouse, an engineer should first check the stability of the
slope.
(e) Safety If there are residences downstream of
any part of the project and you will be changing the natural stream
channel or leading water out of the natural channel in a canal or
pipeline), an engineer should check the safety of the
project.
1.8.......PROJECT COSTS (Back)
1.8.1 Capital Costs
Your project cost estimates will be very preliminary at
this stage. You can use the cost curves in Figure 1-7 to 1-12 to find the
cost of most of the components of your project.
You might want to buy used equipment or materials, such
as:
- turbine
- pump - to be operated in reverse as a
turbine
- generator
- other electrical equipment and wiring
-
steel or plastic pipe
You can save 50 percent or more on the cost of new items.
Ask turbine manufacturers if they have a used turbine or generator that
would suit your project. Scrapyards and used equipment dealers are places
to look for pumps, valves, electrical equipment, wire and pipe. Used
equipment and materials are advertised in newspapers and trade journals
and magazines.
No costs for used equipment are given in this manual --
you will have to estimate costs based on your own enquiries. Beware, there
are no guarantees on used equipment or materials, so make sure you know
what to look for to check that the equipment or materials are in good
condition.
When you have estimated the cost of each component, write
it into the Summary of Project Costs, near the end of this section.
Site Preparation
Timber and brush will probably have to be cleared at the
site of the intake, along the pipeline, at the powerhouse and along the
transmission line. The storage reservoir, if you need one will have to be
cleared before you flood the area. A cat track or access road might have
to be built to get construction materials and equipment to the intake,
pipeline or powerhouse.
The cost of the work depends on the conditions at the
site, therefore no cost curves are given to help you make an estimate. You
could ask a local contractor, logger or cat owner for an approximate
price.
Remember to include a cost -- even if it is only a guess
-- for site preparation in your project cost estimate.
Storage Dam
You decided in Section 1.6.3 whether or not you needed a
storage dam. At this stage you cannot make a reliable estimate of the cost
of the dam. However, if you need to build a dam, include a cost for it in
the Summary of Project Costs to remind yourselt that a dam could be a
major part of the project cost. use the larger of the following
alternative costs:
(a) twice the cost of the intake weir (to be estimated
next), or
(b) ten percent of the total civil, mechanical and
electrical costs (to be calculated in the Summary of Project Costs at
the end of this section).
Intake weir
The intake weir could be built of concrete, rock gabions
or rock-filled timber crib. A concrete dam would probably be the most
expensive, a rock-filled dam the least expensive. Cost curves for concrete
and gabion weirs only have been given in Figure 1.8. If you plan to build
a timber-crib dam, you can make your own cost estimate or use the cost
curve for the gabion weir, knowing that you are probably over estimating
the cost of a timber-crib weir.
The curves in Figure 1.8 are for work done by a building
contractor who pays union wages. Costs can be as low as 60 percent of the
costs shown in Figure 1.8 if you do not hire a contractor and if the
following conditions apply:
(a) you do most of the work yourself or pay wages at
$12 per hour. and
(b) for the concrete dam you mix concrete at the site,
or
(c) for the gabion dam you do not have to pay for
delivery of rocks for the gabions because there are rocks close to the
site.
To find the cost of the weir using Figure 1.8:
(a) decide on the type of weir you will build,
(b) decide on the height of the weir
(c) select the height on the vertical axis, then read
off the cost per metre of weir on the horizontal axis,
(d) estimate the length of weir, and
(e) calculate the cost using the formula cost of weir =
cost/m x length (m).
Example:
Concrete weir 1.5 m high, 6 m long, built by
contractor.
Using Figure 1-8:
Example Your Values
Weir height ..................................... 1.5m
.....................................................m
Weir Length .....................................6.0m
......................................................m
Cost per length of weir (b) .. 210 $/m
..................................................$/M
Cost of weir (a x b)...........................1260 $
.......................................................$
Pipeline Intake
In Figure 1.9 cost curves are shown for a free-standing
intake for a gabion or rock-filled timber weir, and for an intake for a
concrete weir where the backwall of the intake would be part of the
concrete dam.
To find the cost of the intake using Figure 1.9
(a) select the pipeline diameter,
(b) find the submergence required for this pipe
diameter, using the bottom graph,
(c) estimate the actual height of the intake (the
headpond behind the intake weir might be deeper than the minimum
height required in Item 2 above),
(d) find the cost of the intake for the correct
pipeline diameter, using the top graph, and
(e) add the cost of the trashrack from the middle
graph.
Example:
Pipe diameter (Section 1.5.3. "Pipeline") D = 410
mm
Submergence required (bottom graph Figure 1.9) = 1.0
m
Height of intake = height of weir (1.5 m) + 0.5 m = 2.0
m
Cost of intake (using 500 mm pipe diameter on Figure
1.9) = $670
Cost of trashrack for 400 mm pipe (middle graph figure
1.9) $180
Total Cost of Intake $850
Pipeline
Before you can calculate the cost of the pipeline, you
must first make a sketch of the pipeline route (as shown in Sketch (A) in
Figure 1.10) and mark a few ground elevations and lengths along the
pipeline to define the profile. For example, EL. 10 m, EL. 20 m, EL. 30 m;
and Ll, L2, L3' This will enable you to estimate the head on various
sections of the pipeline, (as shown in Sketch (B)) and to choose the
correct cost for each section: this applies to polyethylene plastic pipes
only.
In the table on Figure 1.10, Column #1 shows a Pipe
Classification which corres nds to a range of Gross Heads (or pressure
heads) in Column #2. Each classification of pipe can withstand a pressure
head equal to the maximum in the range in Column #2, for example, "A" pipe
can withstand a gross head up to 31.6 m, and "B" pipe a gross head of 42.2
m. This classification is for polyethylene pipe only; steel pipe is strong
enough to withstand a gross head in excess of 150 m.
For costing polyethylene pipe, mark off the maximum gross
head in each classification on your sketch of the pipeline starting from
the intake, as in Sketch (B), Figure 1.10. Then measure the length of each
classification of pipe, for example LA, LB, LC in Sketch (B).
For each classification, read from the table on Figure
1.10 the cost per metre of pipe under the appropriate pipe diameter;
multiply that unit cost by the length for that classification to give the
cost of that section of pipe.
Example:
Pipe diameter - 410 mm inside diameter. Assume a
nominal outside diameter of 45U mm.
Draw a table as shown below. The lengths LA, LB etc.
are taken from your sketch, similar to Figure 1.10, Sketch (B). The
unit costs of pipe per metre are taken from the table on Figure 1.10.
We will assume a 500 mm pipe in this example, but you could
interpolate the cost for a 450 mm diameter pipe between the costs for
pipes of 315 mm and 500 im-n.
Pipe Length Unit Cost Cost of Section
Classification m $/m $
A LA = 50 155 7750
B LB = 10 205 2050
C LC = 20 265 5300
D LD = 13 324 4212
E LE = 13 518 6734
F LF = 10 518 5180
Total Cost of Pipeline $31,226
Note that the unit costs of 500 mm diameter pipe in
Classes E and F are below the heavy line in the table, indicating that
they are steel pipe. A polyethylene pipe of that diameter cannot withstand
a gross head greater than 70.3 m (classification D).
Add the cost of a valve, from the table on Figure 1.10,
to get the total cost of the pipeline.
Powerhouse
Figure 1.11 shows cost curves for the powerhouse
sub-structure (concrete foundations and floor) and superstructure (wood or
prefabricated metal).
For the sub-structure cost you need the rated output of
your hydro plant in kW, which you should already have estimated. Use the
top graph on Figure 1.11 to find the sub-structure cost.
The superstructure floor area depends on the physical
dimensions of the turbine and generator. The size is related to the
penstock diameter. Use the bottom graph on Figure 1.11 to find the cost of
the superstructure for the penstock size and type of turbine you have
selected.
Add the costs of the sub-structure and superstructure to
get the total powerhouse cost.
Turbine, Generator and Electrical Equipment
Use Figure 1.12 to estimate the cost of the turbine,
generator and electrical equipment in the powerhouse. You need to know the
gross head (from Section 1.4.2) and the energy output hydro plant in kW.
To find the cost of the equipment, find the head on the vertical axis,
draw a line horizontally to intersect the diagonal line with the correct
range of plant output (you can interpolate between these lines), then draw
a vertical line down to the horizontal axis. Read the cost (in $/kW) of
the equipment and multiply by the plant output in kW.
The cost lines on Figure 1.12 were derived from
manufacturers prices and show average costs. They should be used only for
initial estimates, since the prices you actually pay for the turbine,
generator and other electrical equipment could be as much as 40 percent
less than the costs given on Figure 1.12. You will generally get the
quality you pay for: low-priced turbines will probably be made of cheaper
materials and will probably require more repair than higher-priced
turbines.
A very small turbine-generator unit (1.0 - 1.5 kw) with
batteries and a battery-charger might be suitable for lighting and a few
appliances in a small, well-insulated house or summer cabin. The cost of
turbine, generator, batteries, and inverter would be about
1.0 kW $ 9000
1.5 kW $13000
Remember, if you will be converting from existing oil or
propane heating to electric heating, there will be additional costs for
electric heaters and wiring at your house, lodge, camp, or mill. These
additional costs are not covered in this manual.
Transmission Lines and Cables
Use the table below to estimate the cost of transmission
lines or cables running from the hydro plant to the load. Refer to Chapter
4 for a discussion of voltages and different types and sizes of cable you
should use.
Wood Pole Transmission Line
3-phase, 2.4 kV, up to 250 kW: $17000/km
High Voltage Buried Cable
single-phase, up to 85 kW: $15000/km
Tailrace Channel
The tailrace channel is usually a minor cost item,
however, a cost figure should be included in the estimate. A cost curve
cannot be prepared for the tailrace channel because the channel dimensions
depend entirely on the site. Make your own estimate for this item or ask
for an estimate from the person who advised you on the clearing and access
costs.
Contingencies
Contingencies are unexpected costs.
The cost curves in Figure 1.8 to 1.12 were drawn using
cost estimates from manufacturers, suppliers and contractors, and using
costs of projects recently built. However, the cost of your project will
probably be more than you have estimated so far: that's the way things
usually turn out. Some reasons for this:
1. The project you build might be more complicated
than the one you have planned.
2. The dimensions of the project you build might be
larger than you have estimated.
3. The cost curves do not include every possible
expense.
4. Unexpected problems will probably arise during
construction.
5. Add more if the project has accessability
problems.
To avoid surprises, be conservative. Add a contingency
item to your cost estimate, as follows:
1. Add 15 percent if you think your project will be
easy to build, and you think you have included everything.
2. Add 25 percent if you think your project might be
more complicated than most, or if you think you might have
underestimated some of the dimensions such as, length of penstock or
transmission line.
Engineering Costs
You have probably decided whether or not you will hire an
engineer. This section suggests costs to expect for engineering
services.
Even if you want to do all the planning yourself, you
should still provide for the cost of expert advice you might need
unexpectedly.
If you do hire an engineer, here are some guidelines to
help you estimate the costs. For advice on specific problems, or the
design of certain structures, engineers normally charge hourly or daily
rates for their services:
$30 to $70 per hour; $200 to $500 per day.
For a visit to the site, an engineer would expect to be
paid, probably at a reduced rate, while he was travelling, and he would
want to be paid for reasonable expenses. Generally, a self-employed
engineer will charge less than a firm of engineers which has to cover
higher overheads.
If you have to borrow money to build the project, the
banks, or other investor, may ask for a feasibility study report to
show:
(a) the availability of a site for your project,
(b) the availability of sufficient flow and head to
produce the power and energy you need,
(c) an estimate of the costs of the project, and
(d) a simple financial analysis showing loan
repayments and other facts the bank or investor might
require.
For a feasibility study and report, expect to pay between
a minimum of $2000 (that would be a nominal fee) and, $7000 to $15000 for
a project of 50 kW to 250 kW.
For a feasibility study report, and the complete design
and construction supervision of a project, expect to pay 5 to 15 percent
of the project cost, or a minimum of $8000.
Remember, before you hire an engineer or other expert,
ask for an estimate of the cost and a letter detailing exactly what the
engineer will do for the money.
Summary of Project Costs
Make a list of all the costs that apply to your
project.
Example Costs Your Project Costs
Clearing and Access $1000 ......................$
Storage Dam $0 ......................$
Intake $1300 .....................$
Pipeline $31900 .....................$
Turbine, Generator, Electrical Equipment $45500
.....................$
Powerhouse $10700 .....................$
Transmission Line $8000 ....................$
TOTAL COST OF STRUCTURES AND EQUIPMENT (a) $98400
....................$
Engineering $7000 ....................$
Contingencies (15% of (a)) $15000
....................$
TOTAL PROJECT COST $120,400 ....................$
Cost per kW
To check the cost of your project, compare its "Cost per
kW" with other plants. To get the cost in $/kW, divide the total project
cost by the design capacity of the plant (from Section 1.6.2).
Example Your Figures
Total Project Cost (from Summary of Project Costs)
$120,400 ..................................$
Design Capacity (from Section 1.6.2) 35 kW
..............................kW
Cost per kW...............................3,440 $/kW
...........................$/kW
The cost per kW should be within the range of $2000 to
$5000 per kW.
If your figure is around $2000 per kW you have a good
project. If the figure is around $5000 per kW, you still might have a
project that is cheaper than an alternative power source, such as diesel.
You will know this when you have calculated the annual cost of your plant
in Section 1.8.2.
Degree of Confidence in Project Cost Estimate
Only an approximation of the actual project cost can be
expected at this stage in the planning process, when the structures have
yet to be designed and the sites have yet to be carefully examined.
Nevertheless, the actual project cost will probably be within 25 percent
of your estimate.
1.8.2 Annual Costs
You should be aware of the annual cost of energy,
including loan payments and maintenance and repair costs, of your hydro
project. You might want to compare that cost with the cost of energy from
a diesel generator or from a nearby transmission line.
Loan Payments
Decide how much you will have to borrow to cover the
total project cost, then calculate your annual payments (capital and
interest) using a Capital Cost Recovery Factor (CRF) from Table 1.2.
Example:
Assume you want to repay a loan in 10 years, and the
interest rate is 10 percent.
Example Your Values
- Total Project Cost $120400
$..............................
- Equity Available for Project $ 30400
$..............................
- Loan Required (a) $ 90000
$..............................
From Table 1.2:
For: n 10 years ........................years
I =10% ...............................%
Find: CRF 0.163 .................................
Annual Loan Payment:
(CRF) x (a) 0.163 x 90000
........................X......................
=....... $14,670
$...............................................
Maintenance and Repair Costs
Maintenance and repair costs include maintaining the
intake, dam, pipeline, powerhouse and the mechanical and electrical
equipment. The maintenance work that should be done is discussed in
Chapter 3. However, for this initial estimate of annual costs, use 2% of
the Total Project Cost, or $2000 minimum annual maintenance cost.
Total Annual Costs
Add the annual loan payments and the annual maintenance
and repair costs to get the total annual cost. Divide this by the
estimated annual energy output (from Section 1.6.4) to get the cost per
kW.h.
Example:
Example Your Values
- Annual Loan Payment $14,670 ...........$
- Annual Maintenance & Repair Costs $ 2400 ...........$
-Total Annual Costs (a) $17,070 ...........$Annual Energy Output (from
section 1.6.4) (b) 245000 kW.h kW.h
- Cost per kW.h = (a) x 100/(b) = 7.0cents/kW.h cents/kW.h
1.9 ..........Project Worth (Back)
1.10 ..........Continued Planning (Back)
1.11 ..........Project Data Summary (Back)
SUPPLEMENT / MEASURING HEAD AND STREAMFLOW / PRELIMINARY
CHAPTER #2 - SITE EXPLORATION AND STREAMFLOW DATA
2.1 ..........Introduction
2.2 ..........Topographic Maps
2.3 ..........Streamflow Data
2.4 ..........Streamflow Measurement
2.5 ..........Water Quality
2.6 ..........Site Selection for Project Structure
2.7 ..........Head Measurement
2.8 ..........Pipeline Length
2.9 ..........Project Site Topography
2.10 ..........Environmental Aspects
SUPPLEMENT 2.1:
Maps, Air Photos, Streamflow and Climate Data
SUPPLEMENT 2.2:
Installing a Staff Gauge and Weir to Measure Streamflow
CHAPTER #3 - ASSESSMENT OF THE FEASIBILITY OF YOUR HYDRO MANUAL
3.1 ..........Introduction
3.2 ..........Power and Energy Requirements
3.3 ..........Load Planning and Management
3.4 ..........Power and Energy Availability
3.5 ..........Small Hydro Plant Sizing
3.6 ..........Preliminary Arrangement of Structures and Selection of
Equipment
3.7 ..........Project Costs
3.8 ..........Preliminary Assessment of Feasibility
3.9 ..........Continued Planning
SUPPLEMENT 3.1:
Flow Duration Curves
SUPPLEMENT 3.2
Calculating Reservoir Storage
SUPPLEMENT 3.3
Information from Turbine-Generator Manufacturers and Suppliers
CHAPTER #4 - CIVIL WORKS AND EQUIPMENT
Introduction
4.1 ..........Dams
4.2 ..........Intake Structures
4.3 ..........Diversions
4.4 ..........Maintenance of Dams and Intakes
4.5 ..........Factors affecting costs and construction
4.6 ..........Penstock Design
4.7 ..........Characteristics of Pipes
4.8 ..........Plastic Penstocks
4.9 ..........Steel Penstocks
4.10 ..........Forces and Trust Blocking
4.11 ..........Installation of Penstocks
4.12 ..........Water Hammer
4.13 ..........Valves
4.14 ..........Canals, Flumes and Lines Channels
4.15 ..........Turbines
4.16 ..........Water Control to Turbine
4.17 ..........Mechanical Governors
4.18 ..........Electronic Load Control Governors
4.19 ..........Tailwater
4.20 ..........Draft Tubes
4.21 ..........Pumps as Turbines
4.22 ..........Generators
4.23 ..........Mechanical Power Transmission
4.24 ..........Induction Generators
4.25 ..........Synchronizing
4.26 ..........Power Factor
4.27 ..........Electrical Transmission
4.28 ..........Transformers
4.29 ..........Single and Three Phase Systems
4.30 ..........Automatic Emergency Shutdown
4.31 ..........Remote Alarms
4.32 ..........D.C. Systems
4.33 ..........Electrical Inspection and Codes
4.34 ..........Powerhouse Design
4.35 ..........Technical Requirements for Grid Connected Plants
4.36 ..........Consultants, Suppliers and Contractors
CHAPTER #5 - PERMITS, LICENSES AND LEGAL ASPECTS FOR SMALL HYDRO
5.1 ..........Introduction
5.2 ..........Local Involvement
5.3 ..........Provincial Involvement
5.4 ..........Federal Government
5.5 ..........Recommendations APPENDIX
CHAPTER #6 - ECONOMICS AND FINANCING
6.1 ..........Introduction
6.2 ..........Valuation of Energy
6.3 ..........Alternative Energy Costs
6.4 ..........Detailed Economic Assessment
6.5 ..........Financing Alternatives
CHAPTER #7 - GETTING STARTED
7.1 ..........General
7.2 ..........Project Scheduling
7.3 ..........Project Construction
7.4 ..........Practical Notes on Building a Small Hydro Plant
7.5 ..........Practical Notes on Dealing With a Contractor
7.6 ..........Conclusions
CHAPTER #8 - LOW HEAD CONSIDERATIONS
8.1 ..........Introduction
8.2 ..........Water Wheels
8.3 ..........Modern Turbine Types
8.4 ..........Package Visits
8.5 ..........Variable Heads
CHAPTER #9 - COLD WEATHER CONSIDERATIONS
9.1 .......... Cause and Effect
9.2 ..........Climate
9.3 ..........Frost
9.4 ..........Cold Weather
9.5 ..........Ice
9.7 ..........The Dam or Diversion Structure
9.8 ..........Intake Structure
9.9 ..........Canal
9.10 ..........Penstocks
9.11 ..........Powerhouse
9.12 ..........Transmission Lines
9.13 ..........Access
9.14 ..........Conclusion
CHAPTER #10 - ORGANIZATION AND OPERATION OF A PUBLIC UTILITY
10.1 ..........Introduction
10.2 ..........Rationale for Utility Regulation
10.3 ..........Relevant Registration
10.4 ..........Regulatory Alternatives
10.5 ..........Application Procedure
10.6 ..........Organizational Structure and Accounting Procedures
10.7 ..........Implications to Organizing and Operating as a Public
Utility
*GLOSSARY*
A ..........Case Study Examples
B ..........Permit Applications and Agency Addresses
C ..........Small Hydro Suppliers and Contractors
D ..........Small Hydro Consultants
E ..........Small Hydro Computer Programs
F ..........Definitions
G ..........Sources of Financing
H ..........References
Ron Williams
mailto:rwilliam@wlake.com | 
