2. Types of Hydro Turbines
Reaction, Impulse, Mixed Flow
Axial for Low Head (3-33 meters)
Radial or Combined Flow
Kaplan – Variable pitch blades – High efficiency at off load
conditions
Francis – radial, mixed flow – 5-500 meter heads – poor at off
load conditions
Pelton Wheel – Impulse turbine > 50 meter head – high
efficiency over wide range
Fixed Bladed Propeller ~ High efficiency at design conditions
Poor at low flow rates
3. Three Gorges Dam – Yangtze River - China
Installed capacity 22.5 GW - 32 Main Turbines of 700 MW
Capacity factor 0.45
Height 181 m
Length 2,335 m
Crest width 40 m
Base width 115 m
Spillway capacity 16,000 m3
/s
Reservoir Capacity 39.3 km3
Catchment Area 1,000,000 km2
Surface area 1,045 km2
Normal elevation 175 m
Reservoir length 600 km
Max. reservoir width 1.1 km
7. Principle
Po = ρQgH (Watts)
Rain fall > 40 cm/y desired
Ha = Ht - Hf
Q = ⌠ u dA
u ≈ 0.8 us (for rectangular cross section)
8. Pelton Wheel
F = 2ρQj (uj – uc) Force experienced by the cup
Pj = F uc = 2ρQj (uj – uc) uc Power transferred to one cup
Maximum for uc/ uj = 0.5
Hence Pj = ρ Qj uj
2
/ 2 100% efficiency
9. Uj
2
= 2g Ha Bernoulli’s Principle
Pm = ηm ρ Qj (2gHa) / 2 = ηm ρ (a uj) (2gHa ) /2
= ηm ρ a (2gHa)3/2
/ 2 Power from one nozzle
= ηm ρ a n (2gHa)3/2
/ 2 for n nozzles
2 ≤ n ≤ 4
10. Angular Velocity and Turbine Size
Since uc = Rω R = 0.5 uj / ω
R = 0.5 (2gHa)1/2
/ ω
Radius of the nozzle
r2
= Pm / (ηmρnπ(gHa)3/2
(2)1/2
)
Hence r / R = 0.68 (ηmn) -1/2
δ
Where δ = Pm
1/2
ω / [ ρ1/2
(gHa)5/4
] Shape Number
19. Social & Environmental Aspects
Multiple applications – Water storage, fishing,
recreation, bird sanctuaries, river flow control, flood
mitigation
Debt burden – high capital investment, public
displacement, destruction of eco-systems, loss of
historical and cultural heritage, inequitable sharing of
costs and benefits
Small reservoirs and Run-of-River projects
considered having less environmental impacts – China
having large numbers
20. S.
No
Power
Station
Installed
Capacity
(MW)
1. Tarbela 3,578
2. Ghazi
Barotha
1,450
3. Mangla 1,000
4. Warsak 243
5. Chashma 184
6. Khan
Khwar
72
7. Duber
Khwar
130
8. Allai
Khwar
121
9. Others 178
Total
Capacity
6,956
Currently Installed Hydel Power Capacity in Pakistan
22. S.
No
.
Project River Water
Storage
(MAF)
Power
Capacity
(MW)
1. Diamer Basha Indus 8.1 4500
2. Kurram-Tangi Kurram 1.2 84
3. Tarbela-4th
Extetnsion
Indus 1410
4. Munda Swat 1.3 740
5. Kohala Jhelum RoR* 1100
6. Bunji Indus RoR* 7100
7. Dasu Indus 1.15 4320
8. Lower Spat Gah Indus RoR* 496
9. Lower Palas
Valley
Indus RoR* 665
10. Mahl Jhelum RoR* 600
Total Capacity 11.75 21015
Identified
Sites
whose
Feasibility
Study is
Complete
23. Current National News
7 – Wind Projects of 450 MW in the pipeline
50 MW by FFC erected one – 25 out of 33 towers
manufactured in Pakistan
Blades will be locally manufactured in the next
phase
220 MW of Solar Grid applications in the pipeline @
25c/kWh
14000 Biogas plants under installation by Dutch
Govt.
24. What Choices Do We Have ?
The shift in the energy sources is viewed as both a
challenge and an enormous opportunity
The choice we face is either prosperity or decline
We can either remain an importer of oil at increasingly
higher costs or to become an exporter of clean energy
We can allow the climate change to wreck unnatural
havoc across the landscape or we can create jobs
working to prevent its worst effects
The nations that will lead the world in creating new
energy sources will be the nations that lead the 21st
century global economy
