Micro Hydro System by. Andrian L
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Transcript of Micro Hydro System by. Andrian L
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MICRO HYDRO POWERSYSTEMS
Lecture presented as part of the
module: Energy Systems 414
Adriaan Lombard21February 2013
Lecture Overview
Micro Hydro Power Systems 2
1. Hydro Power Introduction
2. Hydro Power Characteristics
2.1. Types of Hydro Power Systems
2.2. Identifying Hydro Power Resource
3. Micro Hydro Power System Design
3.1 Mec hanical Design
- Inlet
- Pipeline
- Turbines
3.2 El ectrical Design
4. Case Study Waterval Micro Hydro Power System
Introduction
Micro Hydro Power Systems 3
Hydro Power size classification
Capacity Classification SAs Share
> 10MW Large Hydro Power
System
95%
1 1 0MW Small Hydro PowerSystem
3.7%
100 1 ,000kW Min i Hyd ro Power
System
1.2%
< 100kW Micro Hydro PowerSystem
0.1%
Hydro power systems
Very significant source of electrical energy
Represents 19% of annual global electrical energy production
Current global installed capacity: 1,010GW
South African installed capacity: 690MW
Micro Hydro Power capacity to be exploited in SA: 65MW
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Introduction
Micro Hydro Power Systems 4
Micro Hydro Power Systems
Disadvantages
High Capital investment is usually required
Advantages
No large complicated and expensive civil works
Low Operating and Maintenance cost
Depending on technology spare parts could be easily available
Base load can be supplied continuously
Reliable systems with long life spans
Capacity factor can be >90%, compared to wind where capacity factor of 20 - 40% usually
achieved
Recent increases in electricity tariffs and those planned for future
Micro Hydro Power Systems becomes more feasible
Hydro Power Characteristics
Micro Hydro Power Systems 5
Types of Hydro Power Systems
1. Reservoir Systems
GariepHydro Power Station 360MW
4 x 90MW Units
Hydro Power Characteristics
Micro Hydro Power Systems 6
Types of Hydro Power Systems
1. Reservoir Systems
2. Run of River Systems
Waterval Micro Hydro Power System
1 x 9kW Unit
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Hydro Power Characteristics
Micro Hydro Power Systems 7
Identifying Hydro Power Resources
Primary factors determining the hydro power capacity of a site:
Available gross head Difference in height between inlet and outlet
Availability of flow
P = gQHN
where:
P: Electrical Power (W)
: Combined Turbine and Generator efficiency (%)
: Density of water, usually 1,000 (kg/m3)
g: Gravitational acceleration, usually 9.81 (m /s2)
Q: Flow rate (m3/s)
HN: Net head (m)
Hydro Power Characteristics
Micro Hydro Power Systems 8
Identifying Hydro Power Resources
Electrical Energy from a Hydro Power System
E = CF(P)t
where:
E: Electrical Energy for a given period (Wh)
CF: Capacity Factor of the system (%)
t: Period over which energy is generated (h)
Hydro Power Characteristics
Micro Hydro Power Systems 9
Identifying Hydro Power Resources
Measuring Gross Head
1. Dumpy Level and staff
2. Global Positioning System (GPS)
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Hydro Power Characteristics
Micro Hydro Power Systems 10
Identifying Hydro Power Resources
Measuring Flow
Most essential parameter in the design of a Micro Hydro Power System
Measurement period depend on flow characteristics of river
0
2
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6
8
10
12
14
1 2 3 4 5 6 7 8 9 1 0 11 12
Flow(m3/s)
Month
N.B!!! Remember the environmental reserve, i.e. minimum flow that need to remain in theriver after water is diverted from the river
- Perennial flow requires once off measurement
- Non perennial flow requires regular measurements taken at least over a full year
0
2
4
6
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12
1 2 3 4 5 6 7 8 9 10 1 1 1 2
Flow(m3/s)
Month
Hydro Power Characteristics
Micro Hydro Power Systems 11
Identifying Hydro Power Resources
Measuring Flow Bucket and Stopwatch Method
Simple method for measuring flow in a pipe
Q = V/t
where:
V: Volume (m3)
t: Time (s)
Hydro Power Characteristics
Micro Hydro Power Systems 12
Identifying Hydro Power Resources
Measuring Flow - Weir Method
Very accurate method for measuring flows in a river course
Different notch shapes, for example: Rectangular, Triangular, etc.
Requirements:
- Notch need to have a very sharp edge
- Slow moving pool of water upstream from the weir, to avoid turbulence
Q = 1.8(W -0.2h)h3/2
where:
W: Width of the notch (m)
h: Height of water above the notch (m)
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Micro Hydro Power System Design
Micro Hydro Power Systems 13
Mechanical Design
Intake
Structure where water enters the pipeline
Prevent silt from entering the pipeline
- Pipe entrance must not be at the bottom of the weir
- Flush pipe at the bottom of the weir
Prevent vortices
- Adequate submergence
- Ensure symmetrical approaching flow conditions
Prevent floating debris from entering the pipeline
- Install trash rack
Micro Hydro Power System Design
Micro Hydro Power Systems 14
Mechanical Design
Pipeline
Dynamics of fluid in a pipeline induces pipeline losses
Head available at bottom of pipeline is less than the measured head
HN= HG-H
where:
HG: Gross measured head (m)
H: Pipeline head loss (m)
Pipeline losses determined by:
Length of pipeline
Diameter of pipeline
Material type
Flow rate
Valves, Bends, etc.
Micro Hydro Power System Design
Micro Hydro Power Systems 15
Mechanical Design
Pipeline
Larger pipe High costs Less losses More power available
Pipeline is often most-expensive part of Micro Hydro Power System
Economic analysis required to optimally size the pipeline for the design flow
120 140 160 180 200 220 2400
0.5
1
1.5
2
2.5
3x 10
5
Diameter of the pipe [mm]
Cost(ZAR)
Pipeline costCost of lost energyTotalcost
Optimum pipeline
diameter
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Micro Hydro Power System Design
Micro Hydro Power Systems 16
Mechanical Design
Pipeline
Comparison of common pipe materials
PVC Pipe Polyethylene Pipe Steel Pipe
Cost Cheapest Cheaper than steel Very Expensive
Corrosion No Corrosion No Corrosion Does Corrode
Sunlight Needs protectionagainst sunlight
Needs protectionagainst sunlight
Susceptible tosunlight
Friction Low Resistance Low Resistance Higher resistanceand increases with
corrosion
Jointing Slide into oneanother
Need to be weldedon site
Weldedor bolted onsite
Handling Easy, light and
available in fixed
lengths
Easy, light and
available in fixed
lengths or long rolls
Difficult, heavy and
available in fixed
lengths
Micro Hydro Power System Design
Micro Hydro Power Systems 17
Mechanical Design
Pipeline
Polyethylene and PVC pipes are mostly used for Micro Hydro Power Systems
Several methods exist to determine friction losses in a pipeline
Friction losses diagrams available for different types of pipes
Diagrams does not include minor losses, i.e. bend losses, valve losses, etc.
Micro Hydro Power System Design
Micro Hydro Power Systems 18
Mechanical Design
Pipeline
Determining the optimum flow for a pipe with a given diameter
Friction losses is a pipeline: H = kQ2
Power delivered by a pipeline: P = gQHN
P = gQ(HG
-H)
P = gQ(HG Q2) = gQHGgQ
3
Maximum Power:
= 0 = gHG 3gQ
2 = HG- 3H
H = 1/3HG
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Micro Hydro Power System Design
Micro Hydro Power Systems 19
Mechanical Design
Turbine
Reaction Turbines
Lowhead (0 100m);Highflow
Fully immersedin water
Torque created by pressure
difference of moving massof waterthroughthe runner
ImpulseTurbines
High head(100m +); Lowflow
Runner notimmersed in water
Torque created by force of jets
of water squirting onto bucketslocated around the
circumference of a wheel
Kaplan Turbine
Francis Turbine
TurgoWheel PeltonW heel
Micro Hydro Power System Design
Micro Hydro Power Systems 20
Mechanical Design
Turbine
Advantages
Low cost due to mass production
Easy construction and maintenance
Spare parts are widely available
Disadvantages
Lowerpeak efficiency
Lit tle turbine mode performance data is
available; pump mode performance dataneedto beusedto select a suitable pump
Alternative Option Pump as Turbine
Some standard sizes do exist, but are usually custom designed for specific application
Can operate at varying flow conditions
Designed for peak efficiency (70 90 %) at available Qand HN
Very expensive
Micro Hydro Power System Design
Micro Hydro Power Systems 21
Mechanical Design
Turbine
To determine nozzle diameter for a Pelton Wheel
Use kinetic energy equation: HN= v2/2g v =
Q = vA=
d =
where:
d: Nozzle diameter (m)
n: Number of nozzles
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Micro Hydro Power System Design
Micro Hydro Power Systems 22
Electrical Design
Micro Hydro Power Systems
Stand-alone system
- With or without battery storage
- Depending on available flow, batterystorage required can be much lessthan for weather-dependent PV
systems
- Designed to meet the average dailydemand
- Other forms of regulators, such asflow control valves
Micro Hydro Power System Design
Micro Hydro Power Systems 23
Electrical Design
Micro Hydro Power Systems
Stand-alone system
Grid-connected systems
- Grid used as virtual storage device
- Synchronous generators with grid
interfaces requires precise speedcontrol (very expensive)
- Asynchronous generators requires
operation beyond synchronous speed
(relative cheap option as very littleelectrical interfaces are required)
Micro Hydro Power System Design
Micro Hydro Power Systems 24
Case Study Waterval Micro Hydro Power System
Measured Gross Head with GPS: 79m
Minimum Flow: 0.03m3/s
Rectangular Weir plate design
Suggested water height above the notch: 0.05m
W =
W =
W = 1.5m
Determine maximum flow to be measured:
Consider constraint of W > 3h; h = 0.5m
Q =
Q =
Q = 0.89m3/s
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Micro Hydro Power System Design
Micro Hydro Power Systems 25
Case Study Waterval Micro Hydro Power System
Pipeline losses
Consider:
PVC Pipeline with length of 470m and diameter of 100mm
Flow of 0.02m3/s
Conversion factors:
1foot = 0.3048m
448.8gpm = 0.02832m3/s 0.02m3/s = 317gpm
Friction loss:
4.2ft of head for every 100ft of pipe
1.28m of head for every 30.48m of pipe
H= 470m x 1.28m/30.48m
H= 19.74m
Micro Hydro Power System Design
Micro Hydro Power Systems 26
Case Study Waterval Micro Hydro Power System
Generated Power and Energy
Net Head available:
HN = HGH
HN = 79 19.74
HN = 59.3m
Generated Power:
Assume a combined generator and turbine efficiency of 60%
P = gQHN
P = (0.6)(1000)(9.81)(0.02)(60.2)
P = 6.98kW
Generated Energy over 31 days (1 month):
Assume a Capacity Factor of 95%
E = CF(P)t
E = (0.95)(8.5)(31)(24)E = 4933kWh
Micro Hydro Power System Design
Micro Hydro Power Systems 27
Case Study Waterval Micro Hydro Power System
Maximum power from a given pipe diameter
Consider:
PVC Pipeline with length of 470m and diameter of 100mm
Gross head of 79m
5.6ft of head for every 100ft of pipe
Optimum flow rate: 365gpm = 0.023m3/s
Maximum Head loss: H = 1/3HG = 26.3m
Net Head: 52.7m
Generated power: 7.13kW
Generated energy over a month: 5039kWh
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Micro Hydro Power System Design
Micro Hydro Power Systems 28
Case Study Waterval Micro Hydro Power System
Peltonwheel Nozzle Diameter
Consider:
Peltonwheel having 4 Nozzles
d =
d =
d = 13.5mm
Micro Hydro Power System Design
Micro Hydro Power Systems 29
Case Study Waterval Micro Hydro Power System
Pipeline losses
0
10
20
30
40
50
60
70
80
90
0 5 10 15 20 25 30
Netheadattheendofthemainpipeline(m)
Flow (l/s)
Measured Results
Calculated Results
Micro Hydro Power System Design
Micro Hydro Power Systems 30
Case Study Waterval Micro Hydro Power System
Power generated by the Micro Hydro Power System
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3/7/2009
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GeneratedPower
(kW)
Date
Generated active power Rated capacity of the generator
Systemdowntime
Maintenance
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Micro Hydro Power System Design
Micro Hydro Power Systems 31
Case Study Waterval Micro Hydro Power System
Energy generated by the Micro Hydro Power System
8.14
3.22 3.624.93
22.10822
9.04263
13.20834 13.06559
0
5
10
15
20
25
Power(kW)andEnergy(MWh)
Average Power Generated (kW) Total Energy Generated (MWh)
Generated by the
hydro system
Consumed from the
Hydro system
Consumed from
the grid
Delivered to the
grid
12 March 2009 01 October 2009
Micro Hydro Power System Design
Micro Hydro Power Systems 32
Case Study Waterval Micro Hydro Power System
Micro Hydro Power System Capital Expenditure R135,610
Annual Operation and Maintenance Cost R350
Micro Hydro Power System Design
Micro Hydro Power Systems 33
Case Study Waterval Micro Hydro Power System
-150
-100
-50
0
50
100
150
200
250300
350
400
450
0 1 2 3 4 5 6 7 8 9 1 011 12 13 14 15 16 17 18 19 20
NPVoftheMHPS(ThousandZAR)
MHPS Life Cycle (Years)
Payback Period 4.3 Years
Net Present Value R396,166
Cost of electricity 10.2c/kWh
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Micro Hydro Power System Design
Micro Hydro Power Systems 34
Case Study Waterval Micro Hydro Power System
Micro Hydro Power System Design
Micro Hydro Power Systems 35
Thanks