HYDROPOWER ENGINEERINGPRINCIPLES OF HYDROPOWER

ENGINEERINGBy:-

ARKAN IBRAHIMAZHEEN FATAH

HINDREEN NAZIF Submitted to :-

Doç.Dr.Aytaç Güven

Content:-

• What is Hydropower(Introduction)?

• Hydropower potential

• Classifications of Hydropower Plants

• layouts of hydropower plants

What is Hydropower?

Introduction

Water CycleUnderstanding the water cycle is important in order to understand hydropower. The energy driving the water cycle comes from radiant energy released by the sun that heats the water and causes it to evaporate.

Gravitational Energy

Kinetic energy is the energy of motion. Any moving

object has kinetic energy.

-Humans first learned to harness the kinetic energy in water by using waterwheels.

-Waterwheels convert the kinetic energy of flowing water to mechanical energy.

Harnessing Water Power

The necessary head can be created in different ways of which two have been practically accepted These are:

1. Building a dam across a stream to hold back water and release it through a channel, conduit or a tunnel:

Dam Types

• Arch

• Gravity

• Buttress

• Embankment or Earth

Arch Dams

Concrete Gravity Dams

Buttress Dams

Embankment Dams

2. Divert a part of the stream by creating a low-head diversion structure like barrage.

Hydropower potential

Hydropower potential

WHAT IS HYDRO POWER?• The term ‘hydro’ is the Greek word for water and

hydropower is the energy contained in water .

• Hydropower is considered a renewable energy source.

• Hydropower transforms the potential energy of a mass of water flowing in a river or stream with a certain vertical fall (termed the “head”).

• The power output from the scheme is proportional to the flow and to the head

Head = the height from which water falls

PRINCIPAL COMPONENTS OF HYDROELECRIC SCHEME

FIRST ELEMENT :-

DAMS

2nd ELEMENT:-

INTAKE

3rd ELEMENT:-PENSTOCK

4th ELEMENT

TURBINES

5TH ELEMENTGENERATOR

6TH ELEMENT:-

TRANSFORMERS

7TH ELEMENTOUTFLOW / TAILRACE:-

After passing through the turbine the water returns to the river trough a short canal called a tailrace.

8TH ELEMENTPOWER HOUSE:-

DAM TURBINE

POWER HOUSE

INTAKE

GENERATOR

PENSTOCKRESEV

OIR

POWER LINE

TRANSFORMER

A SIMPLE

OVER VIEW

The mechanical energy produced by the turbine is converted into electric energy using a turbine generator. Inside the generator, the shaft of the turbine spins a magnet inside coils of copper wire. It is a fact of nature that moving a magnet near a conductor causes an electric current.

How a Hydroelectric Power System Works –

• In order to evaluate the power of flowing water, we may assume a uniform steady flow between two cross-sections of a river, with H (meters) of difference in water surface elevation between two sections for a flow of Q (m3/s), the power (P) can be expressed as :

where v1 and v2 are the mean velocities in the two sections. Neglecting the usually slight difference in the kinetic energy and assuming a value of γ as 9810N/m2, one obtains the expression of power as:

Since an energy of 1000Nm/s can be represented as 1kW (1kilo-Watt), one may write the following

in order to evaluate the hydropower potential of a site , it is necessary to have knowledge of the hydrology or stream flow of the site, since that would be varying everyday. Hence the following criteria are considered:

1. Minimum potential power is based on the smallest runoff available in the stream at all times having duration of 100 percent.

2. Small potential power is calculated from the 95 percent duration discharge .

3. Medium or average potential power is gained from the 50 percent duration discharge.

4. Mean potential power results by evaluating the annual mean runoff.

World’s First Hydropower Plant

-In 1880, the Grand Rapids Electric Light and Power Company used a water turbine to generate enough electricity to power 16 lights.

-Soon after, in 1882, the world’s first hydroelectric power plant began operation on the Fox River in Appleton,

it is not economically feasible to harness the entire runoff of a river during flood (as that would require a huge storage) a discharge-duration curve may be prepared (Figure below) which plots the daily discharges at a location in the decreasing order of magnitude starting from the largest daily discharge observed during the year and going up to the minimum daily discharge.

• THEORETICAL- The maximum potential that exists no losses.40,000 TWh

• TECHNICAL- From technical point of view, extremely low heads (less than around 0.5m), head losses in water ways, efficiency losses in the hydraulic and electrical machines, are considered as infeasible. 20,000 TWh

• ECONOMIC- Calculated after detailed environmental, geological, and other economic(alternative sources of power like oil and coal) constraints 9,800 TWh

Hydropower potential is commonly divided into three categories:

Top ten countries (in terms of capacity)

CountryAnnual hydroelectric

production (TWh)Installed

capacity (GW)Capacity

factor% of total

production

China 652.05 196.79 0.37 22.25

Canada 369.5 88.974 0.59 61.12

Brazil 363.8 69.080 0.56 85.56

United States 250.6 79.511 0.42 5.74

Russia 167.0 45.000 0.42 17.64

Norway 140.5 27.528 0.49 98.25

India 115.6 33.600 0.43 15.80

Venezuela 85.96 14.622 0.67 69.20

Japan 69.2 27.229 0.37 7.21

Sweden 65.5 16.209 0.46 44.34

Ten of the largest hydroelectric producers as at 2009.[44][46]

Global Installed Capacity

Under Construction…

Turkey's hydropower developmentHydroelectric power facilities were first developed in the region in 1935, and their development increased steadily until 1974.

Currently, 22.8% of all electricity generated in the country comes from hydropower, (according to data from the International Energy Agency).

Turkey has 478 installed hydropower plants located in 69 provinces, with a total installed capacity of 15.1 GW.

There are 534 plants currently being planned, with 160 of those under construction at around 15 GW of capacity.

Name Power Output in Megawatt

Ataturk Dam 2400 MW

Karakaya Dam 1800 MW

Ilisu Dam 1200 MW

Birecik Dam 852 MW

Examples of Largest stations in Turkey

CLASSIFICATION OF HYDROPOWER PLANTS

CLASSIFICATION OF HYDROPOWER PLANTS :

Classification of hydropower plants

According to Capacity

Large

Medium

Small

Mini

Micro

Pico

According to head

High

Medium

Low

According to purpose

Single purpose

Multi purpose

According to facility types

Run-of-River

Reservoirs

In-stream

Pumped storage

Tidal Plants

According to hydrological

relation

Single

Cascade

According to transmission

system

Isolated

Connected to grid

LARGE: >100 MW

MEDIUM: 25 – 100 MW

SMALL: 1-25 MW

MINI: 100 KW - 1MW

MICRO: 5 – 100 KW

PICO: < 5 KW

Large Scale Hydropower plant

Small Scale Hydropower Plant

Micro Hydropower Plant

small hydro power definitions in different countries:-

COUNTRY NAME SHP (MW)

Mauritius ≤ 0.05

Italy ≤ 3

Dominican Republic, Guatemala, Macedonia ≤ 5

Marocco ≤ 8

Afghanistan, Burundi, Iran, Malaysia, Mali, Nepal, Norway, Sri Lanka, Tunisia,

Kenya, Uganda, Zambia, Madagascar, Armenia, Austria, Croatia, Montenegro,

Nigeria, Turkey, Serbia, Slovenia, Switzerland, Azerbaijan, Cambodia,

Philippines, Indonesia, Senegal

≤ 10

Georgia ≤ 13

Bangladesh, Laos, Lesotho, Thailand ≤ 15

El Salvador, Peru ≤ 20

Bhutan, India, Mozambique ≤ 25

Argentina, Brazil, Mexico, Benin, United States ≤ 30

Canada, China, Pakistan, New Zealand ≤ 50

LOW HEAD:Low head hydro power applications use river current or tidal flows of 30 meters or

less to produce energy.

These applications do not need to dam or retain water to create hydraulic head, the

head is only a few meters.

Using the current of a river or the naturally occurring tidal flow to create electricity

may provide a renewable energy source that will have a minimal impact on the

environment.

Figure-sectional view of low head hydropower plant

MEDIUM HEAD:A power station operating under heads from 30m to 300m.

Figure- sectional view of medium head hydropower plant

HIGH HEAD:A power station operating under heads above about 300m.

A head of 200m/250m is considered as the limit between medium

and high head power stations.

Figure- high head hydropower plant

Figure-(a) single stage hydropower development scheme

(b) cascade or multistage hydropower system

SINGLE STAGE- When the

run off from a single

hydropower plant is diverted

back into river or for any other

purpose other than power

generation, the setup is known

as Single Stage

CASCADE SYSTEM-

When two or more hydropower

plants are used in series such

that the runoff discharge of

one hydro power plant is used

as the is a intake discharge of

the second hydro power plant

such a system is known as

CASCADE hydropower plant.

SINGLE PURPOSE: When the whole soul purpose of a project is

to produce electricity then such a project is known as a Single

Purpose Hydro Power Project.

MULTIPURPOSE : When the water used in hydropower project

is to be used for other purposes like irrigation, flood control or

fisheries then such a project is known as Multi Purpose Hydro

Power Project.

These are hydro power plants that utilize the stream flow as it

comes , without any storage being provided.

RUN-OF-RIVER TYPE

Figure-Run-of-River hydropower plant

Hydropower plants with storage are supplied with water from large storage

reservoir that have been

developed by constructing dams across rivers.

Assured flow for hydro power generation is more certain for the storage

schemes than the run-of-river schemes.

STORAGE (RESERVOIR) TYPE

Figure-pumped storage hydropower plant

PUMPED STORAGE TYPE

Figure-pumped storage hydropower plant

Pumped storage type hydropower plants are those which utilize the flow of water from a

reservoir at higher potential to one at lower potential.

During off-peak hours, the reversible units are supplied with the excess electricity

available in the power grid which then pumps part of the water of the tail-water pond back

into the head-water pond.

IN-STREAM

When the velocity of water

i.e. kinetic energy flowing

in the stream is used for

conversion into electrical

power, then the system is

known as In-stream.

Photograph of In-stream hydro power system

Tidal Plants• another form of water energy that is used for hydropower

development: the variation of the ocean water with time due to the moon’s pull, which is termed as the Tide.

• The water rises and falls during the day. The advantage of this rise and fall is taken in a tidal plant.

Tidal Plants

Tidal PlantsTHE RANCETIDAL POWERPLANT

IN FRANCE

Tidal Plants

ISOLATED: Whenever a hydropower plant is set up in

a remote area in order to meet the local demands then

such a hydropower plant is known as Isolated System.

CONNECTED TO GRID: Whenever the hydropower

plant is set up to meet the demands of areas which are at a

fair distance from the plant, then the transmission of

power takes through the grid system. Such a setup is

referred to as Connected to grid.

working principle of hydroelectric power plant is depends on:

1- Height of water.

2- Volume of water flowing per unit time.

3- Efficiency of turbine.

hL= hf + hm

Frictional head losses : are losses due to shear stress on the pipe walls

Minor head losses : are losses due to sudden changes in pipes such as elbows, valves, inlets, etc .

Tailrace :The channel that carries water away from the powerhouse.

Tailwater: The downstream water of the powerhouse.

Head & Losses

Hydroelectric Power and Energy

teHQE

eHQP

g

g

P= Power (KW)E=Energy (KWh)Q= Discharge (m3/sec)Hg= Gross head (m)e =overall unit efficiency (%)e = e(hydraulic) x e(turbine) x e(generator)

P= 1000𝑘𝑔

𝑚3 𝑥𝑚

𝑠𝑒𝑐2𝑥𝑚3

𝑠𝑒𝑐𝑥 𝑚

ρw = 1000 Kg/𝑚3

P = ρ. 𝑔. 𝑄. 𝐻. 𝑒𝑜P = ϒ.𝑄.𝐻. 𝑒𝑜

1000𝑘𝑔

𝑚3 𝑥𝑚5

𝑠𝑒𝑐3= 1000 kg x

𝑚2

𝑠𝑒𝑐3

Where kg x 𝑚2

𝑠𝑒𝑐3= 𝑊

SO, 1000kg x 𝑚2

𝑠𝑒𝑐3= 1000 𝑊 = 1𝐾𝑊

Approve unit of Power

Example about hydroelectric power

In a hydroelectric power plant, the water surface on the crest of the dam is at elevation 75.3 m while the water surface just at the outlet of the head gate is at elevation 74.4 m. The head gate has 5 gates of 0.91 m x 0.91 m leading to the penstock and are fully opened. Assume 61% as coefficient of discharge, determine :

i) The quantity of water that enters the hydraulic turbine in m3/sec

ii) The KW power that the turbine will developed, assuming 90% efficiency and the turbine is 122 m below the entrance of the penstock . ( by using Hg )

iii) determine the power that the turbine will developed assuming 85% efficiency under the same conditions as b. (by using Hn)

Solution :

h = (75.3-74.4) + (0.91

2) = 1.355 m

i)

v - theoretical velocity just at the outlet of the head gate

v = 2gh

v = 2x9.81x1.355

v = 5.156 m/sec

Q = 5(0.91 x 0.91)(5.156) = 21.35 m3/sec

ii)

Q' = 0.61(21.35) = 13.02 m3/sec (actual flow)

Fluid Power = 1000 x (9.81) x Q‘ x (1.355+122) x (0.90) = 14,180 KW

P = ρ. 𝑔. 𝑄. 𝐻. 𝑒𝑜

v = 13.02

5(0.91 x 0.91)

v = 3.14 m/sec (actual velocity at each gate)

iii)

𝑣2

2𝑔= 0.504 m

he = entrance loss

he = ke (𝑣2

2𝑔)

ke = 0.5

he = 5(0.5)(0.504) = 1.25m (minor head loss for 5 gates)

H = (1.355 + 122) - 1.25 = 122.105 m

Fluid Power = 1000 x (9.81)(13.02)(122.105)(0.85) = 13,257 KW

classifies hydropower plants according to their operating functions as follows:

1. Base load power plant : are power stations which can consistently generate the electrical power needed to satisfy minimum demand. That demand is called the base load requirement, it is the minimum level of demand on an electrical grid over 24 hours.

2. Peaking power plant : are power plants that generally run only when there is a high demand, known as peak demand, for electricity Because they supply power only occasionally (sometimes), the power supplied commands a much higher price per kilowatt hour than base load power.

Base load electricity vs. Peak Load

Notice that throughout the middle of the night, the electricity demand is roughly 10GW. Throughout the day it ramps past 15GW. Base load electricity in this case is 10GW. It is the minimum amount of electricity needed at any point. All power plants that provide base load electricity will run 24 hours a day. Base load power plants need to be very reliable so they don’t shut down unexpectedly.

Peak electricity is whatever is above base load. In the above figure, it is the all the extra stuff from 10GW to 15GW.

Layouts of hydropower plants

Hydropower plant scheme layout and it is Working

1. hydroelectric power plant required a water reservoir so this plant are constructed through Dam.

Hydropower plant scheme layout and it is Working

1. hydroelectric power plant required a water reservoir so this plant are constructed through Dam.

Hydropower plant scheme layout and it is Working

2. Water Stored dam has potential energy the water under pressure is carried by penstock (pipe) due to the control gate and change potential to kinetic energy due to movement of water .

Hydropower plant scheme layout and it is Working

3. Penstock is a pipeline that supply water to the turbine.

Hydropower plant scheme layout and it is Working

4. surge tank : produces the excess water force on the penstock

Hydropower plant scheme layout and it is Working

5.trash rack : prevent the debris ( piece of rock ) from getting enter into the power house

Hydropower plant scheme layout and it is Working

6. due to the force of water the turbine will start rotating and due to it the mechanical energy is produced .

Hydropower plant scheme layout and it is Working

7. the shaft due to turbine is connected to the generator , As the turbine blades turn, so do a series of magnets inside the generator and producing (AC) by moving electrons and therefore produce electrical energy .

Hydropower plant scheme layout and it is Working

8. the voltage of this electricity Is create by converting (AC) to higher voltage then release it by using transformer and then transform by distribution lines(power line) to the city .

Hydropower plant scheme layout and it is Working

9. and also we have draft tube after running the turbine the water is passed to the downstream water level by draft tube .

Advantages

1. the most important advantage is that it keeps the environment clean .2. when electricity is not needed then the sluice gate is closed to stop the generation

of electricity .

Disadvantage

1. Constructing hydroelectric power plants and dams is very expensive and it is required large area .

2. planning a hydroelectric plant and reservoir may lead to the disruption of the lives of people as they have to relocate to another area.

Advantage and disadvantage of hydroelectricity power plant

High and medium head developmentUsually, there could be two types of power scheme layout: • Concentrated fall schemes • Diversion schemes

In the concentrated fall type projects, the powerhouse would be built at the toe of a concrete gravity dam, shown as in the figure bellow :

In the diversion type of layout, the diversion could be using a canal and a penstock (Figure 11) or a tunnel and a penstock (Figure 12). The former is usually called the Open-Flow Diversion System and the latter Pressure Diversion System.

1. Dam 2. Intake diversion conduit3. Head pond4. Spillway5. Power house6. Tailrace7. Penstocks8. Reservoir

Figure 11

1. Watercourse2. Dam3. Intake structures4. Diversion tunnel5. Surge tank6. Penstock fork house7. Penstocks8. Penstocks support9. Power house10. Power line

Figure 12

Power Channel

It is the channel through which water is being carried to the forebay tank for feeding to penstock. The various types of power channels are listed below :

OPEN CHANNEL

• Rectangular• Trapezoidal• Triangular

CLOSED CONDUIT

• Reinforced concrete pipe• PVC pipes• Steel pipes

Low head development

Here too, two types of layouts may be possible: • In-stream scheme • Diversion scheme

In the in-stream type of project, the powerhouse would be built as a part of the diversion structure, as shown in Figure 2(a) or a general detailed view in Figure 6

• In the diversion type of scheme, there has to be a diversion structure as well as a diversion canal, as shown in Figure 2(b). The power house may be located at some convenient point of the canal, that is, at its upstream end, middle, or at the downstream end.

Position of power housesAs might have been noticed from the layouts, there could be a variety of position for the power house with respect to natural ground level.the following types of power stations, which may be constructed as per site conditions:

1. Surface power station or over ground power station: A power station which is constructed over the ground with necessary open excavation for foundations.

2. Underground power station: A power station located in a cavity in the ground with no part of the structure exposed to outside.

3. Semi Underground powerhouse: Some components of the power house are underground, while others are on surface. The advantages of both surface & underground are clubbed together in a semi-underground powerhouse, provided topography and geology so permit.

Electrical terms associated with hydropower engineering

Load factor: It is the ratio of the average load during a certain period to the maximum or peak load during that period, and we have daily load factor, weekly load factor, monthly load factor and yearly load factor depending upon the time period.

Load factor is usually expressed as a percentage.

𝑳𝒐𝒂𝒅 𝑭𝒂𝒄𝒕𝒐𝒓 𝑳𝑭 =𝒂𝒗𝒆. 𝒍𝒐𝒂𝒅

𝒑𝒆𝒂𝒌 𝒍𝒐𝒂𝒅=

𝒕𝒐𝒕𝒂𝒍 𝒆𝒏𝒆𝒓𝒈𝒚 𝒑𝒓𝒐𝒅𝒖𝒄𝒆𝒅

𝒕𝒐𝒕𝒂𝒍 𝒆𝒏𝒆𝒓𝒈𝒚 𝒄𝒐𝒓𝒓𝒆𝒔𝒑𝒐𝒏𝒅𝒊𝒏𝒈 𝒕𝒐 𝒑𝒆𝒂𝒌 𝒍𝒐𝒂𝒅

installed capacity: The maximum power which can be developed by the generators.

The Firm Power: The firm power (or primary power) is the amount of power which a plant can deliver throughout the year (or 100% of time). It is the power which will be available when the flow in the river is minimum for a run-off river plant.

Surplus (secondary) power: The secondary power (or surplus power) is the amount of power which is in the excess of the firm power. In a run-off river plant, the secondary power is available when the discharge in the river is greater than the minimum discharge.

Utilization factor or Plant use factor: It is the ratio of peak load developed duringa certain period to the installed capacity of the plant.

𝐔𝐭𝐢𝐥𝐢𝐳𝐚𝐭𝐢𝐨𝐧 𝐟𝐚𝐜𝐭𝐨𝐫 𝑼𝑭 =𝒑𝒆𝒂𝒌 𝒍𝒐𝒂𝒅

𝑰𝒏𝒔𝒕𝒂𝒍𝒍𝒆𝒅 𝒄𝒂𝒑𝒂𝒄𝒊𝒕𝒚

Example:Two Turbo Generators each of capacity 25000 KW have been installed at a hydel. power plant. During certain period the load on the hydel. plant varies from 15000 KW to 40000 KW. Calculate as follows:a. The total installed capacity.b. The load factor.c. The utilization factor.

Solution:

a) the total installed capacity = 2*25000 = 50000 KW

b) The Load factor LF =average load/peak load= 27500/40000 = .6875 = 68.75%

c)Utilization factor = Peak load/installed capacity = 40000/50000 =0.80 = 80.00%

Time(hr) 0-6 6-10 10-12 12-16 16-20 20-22 22-24

Load(Mw) 30 70 90 60 100 80 60

Example:A power station supplies the following loads to the consumer as given below; 1. Draw the load curve.2.find the load factor for the plant .

Solution:

1.

2. For Load factor calculation

Average load = (30*6+70*4+90*2+60*4+100*4+80*2+60*2)/24 = 1560/24

Load Factor (LF) = Average Load/Peak Load = 1560/(100*24) = 0.65 = 65.0%

Time(hr) 0-6 6-10 10-12 12-16 16-20 20-22 22-24

Load(Mw) 30 70 90 60 100 80 60

References

Www.Eai.In

• RENEWABLE ENERGY TECHNOLOGIES: COST ANALYSIS SERIES

volume 1: power sector ,issue 3/5, JUNE 2012

http://www.Irena.Org/menu/index.Aspx?Mnu=subcat&primenuid=36&ca

tid=141&subcatid=232

NPTEL Module CE IIT Kharaghpur Chapter:5 Version 2.

Http://www.eai.in/ref/ae/hyd/hyd.html#sthash.pvmI3H9c.dpuf

Mosonyi, Emil (1991) “Water power development”, Akademia Budapest.

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