1
OASYS – South Asia: Dundee Workshop 2011
Dr Arthur Williams
Dept. of Electrical & Electronic Engineering
University of Nottingham, UK
Micro-hydro applications in rural areas
2
Types of hydropower
Micro hydro is usually “Run-of-river”
Conventional hydropower usually
uses a reservoir
(Llyn Brianne, Wales: 4 MW)
<10 MW is called “Small” hydro
(Las Juntas,
Peru: 25 kW)
Pico hydro in SE Asia (< 5kW)
3
Where are the potential sites?
Hydropower usually uses the potential energy of water:
mass flow × head ×
gravity
Good sites either have high head
Or
high flow
Many good sites in remote rural areas
AKRSP, Pakistan
4
Rural Electrification Options
Kushadevi - Nepal
- site of a 3 kW Pico Hydro project
Grid Connection
• too expensive
• unreliable, especially in mountainous areas
Stand-alone options
• rechargeable batteries
• Solar Home Systems
Mini-grid options
• diesel generators
• Pico Hydro
5
Rural Electrification Options
0 10 20 30 40 50 60 70 80
300-1000 W
50 - 300 W
300 W
300 W
300-1000 WP
etr
ol o
r
Die
se
lS
ola
r P
V
PV
-Win
d
hyb
rid
Win
dP
ico
hyd
ro
Typ
e o
f G
en
era
tor
Predicted Cost in 2010 (UScent/kWh)
Minimum
Lower Range
Probable Range
Higher Range
2006 World
Bank study:
Off-grid
Costs.
2002 study in
Kenya:
PH: 15 ¢
PV: >$1
6
Civil works for pico hydro
For higher head schemes, Polyethylene or PVC pipe is easily available
and light to transport.
Simple intake structures
Storage only for evening
use in dry season
Minimal use of cement
Magdale
na,
Peru
K
ath
am
ba, K
enya
7
Pico hydro turbine types
For medium heads: crossflow or pump as turbine -
imported or locally made - also uses induction motor
as generator
• For higher heads: locally manufactured Pelton turbine
Thailand: project of Border Green Energy
8
Pico hydro turbine types
• For low heads: propeller turbine (with scroll casing or open flume)
Kathmandu University
Leverh
ulm
e P
roje
ct,
Nott
’m T
rent U
niv
ers
ity
9
Village hydro cost breakdown
Average % costs for Kenyan schemes (2001)
Note: No battery costs
Relative Cost
4%8%
22%
38%
4%
24%
Civil works
Penstock
Turbine,Gen.+Control
Cable+Lamps
Wiring labour
Design+Management
10
Balancing costs and efficiency
Reducing cable thickness saves on cost/kW
- but there is a limit to acceptable volt drop (ΔV)
Max. Voltage Drop 5% 10%
Cable Cost £2,000 £1,600
Power delivered to Consumers
0.97 kW 0.94 kW
Total Scheme Cost (1 kW scheme)
£5,000 £4,600
Cost per power delivered
£5,155/kW £4,894/kW
(-5%)
Turbine House
Intake
9 Z
Bb
4 0 Z
8 3 9 Z C c
51 Z
5 4 Z
Sp u r C
4 5 Z
5 2 Z
5 3 Z
1
2
3
46 Z6
4 4 Z3 5 Z
36 Z37 Z
38 Z
41 Z
42 Z
43 Z
C a
5
4 C b
7
3
4 8 Z
50 Z Be
7 Z 9
Ba
58 Z
2 Z
Tu rb i ne h o u s e
5 7 Z
Sp u r A 2
4
1 Z
3 Z3
4 Z
5 Z
6 Z
4
59 Z
560 Z
Sp u r B
Pe n s to c k
8 Z
5
29 Z 31 Z
49 Z
32 Z1 2 Bd
33 Z
34 Z
1 1
21 Z
30 Z
28 Z
22 Z
23 Z24 Z
25 Z
26 Z 27 Z
6
7
17 Z 18 Z
10 C11 C
12 Z
13 Z14 Z15 Z
16 Z8
20 Z
Bc
19 Z1 0
A typical village layout (Kathamba, Kenya).
Most spurs have several branches
Houses are clustered.
Load limiters used.
9 Z
Bb
T u rb i n e h o u s e
4 0 Z
8 3 9 Z C c
5 1 Z
5 4 Z
4 5 Z
Sp u r C5 2 Z
5 3 Z
1
2
3
6
4 4 Z
4 6 Z
3 5 Z
3 6 Z3 7 Z
3 8 Z
4 1 Z
4 2 Z
4 3 Z
C a
5
4 C b
7
3
4 8 Z
5 0 Z Be
Mu k e n g e r ia R iv e r
7 Z 9
2 Z
Ba5 7 Z
5 8 Z
1 Z
Sp u r A 2
4
3 Z3
4 Z
5 Z
6 Z
4
5 9 Z
56 0 Z
Sp u r B
8 Z
5
3 0 Z
1 0 0 me tr e s
4 9 Z
2 9 Z 3 1 Z
3 2 Z1 2 Bd
3 3 Z
3 4 Z
1 1
2 1 Z
2 8 Z
2 2 Z
2 3 Z2 4 Z
2 5 Z
2 6 Z 2 7 Z
6
7
1 7 Z 1 8 Z
1 0 C1 1 C
1 2 Z
1 3 Z1 4 Z1 5 Z
1 6 Z8
2 0 Z
Bc
1 9 Z1 0
ViPOR program applied to Kathamba layout
No cable across valley
13
Cable selection program (v.2) (under development)
Spurs and branches; Accurate positioning; Variable loads.
14
Off-grid schemes in rural areas are increasing
Growth in rural households accessing electricity in Sri Lanka.
Mini-grid schemes can be connected to
a grid extension.
15
LED lamps: an alternative?
“Hurricane” lamp – 800W (based on rate of kerosene
consumption!) Same lumens as a 2W LED!
LED colour balance can be improved by mixing
16
Conclusions - lighting
Photo Source: LUTW
LED v CFL
V. low power; narrow beam; v. long life;
Efficient for LV systems
Low power; wide beam; higher efficacy; long life;
Better for mains voltages.
17
Dissemination
Support for local entrepreneurs: Local manufacture of turbines.
Practical Action have useful publications
Photo: Phil Maher, Pico Energy Ltd.
Management models, Peru
18
On-line information for Pico Hydro @
www.picohydro.org.uk www.pumpsasturbines.org.uk
Navigation
Home Page
Pico Hydro
What's New
Download
Publications
Newsletter
Inquiries
Downloadable Publications
Pico Hydro for Village Power
- Design and Installation Manual
Pico Power Pack
- A Practical Guide to Design and Manufacture
Water Power for a Village Business
Pico Hidro - Potencia para Aldeas (Un Versión Español).
Case Studies in Kenya & Nepal
19
Conclusions
Photo Source: LUTW
• Village-based mini-grids are suitable for rural electrification
• Renewable energy based systems are cost-effective (esp. hydro)
• Costs can be reduced through: 1. local manufacture
2. using PC-based design for turbines, pipes and distribution cables
Compared with kerosene lamps or dry-cell torches, Electric lighting is
• Cheaper
• Cleaner
• Safer
December 2010: Zhiture , one of two new Micro-hydro plants installed by AKRSP in Chitral, Pakistan.
20
Extra slides: 1. Water flow variation
Flow available will vary with seasons and from year to year.
Available flow is shown by a flow duration curve.
Qav is (rainfall - evaporation)
× catchment area.
Without storage, a
hydropower plant will be
sized to use a flow rate < Qav.
Flow duration curve
0
1
2
3
4
5
6
0 0.2 0.4 0.6 0.8 1
Probability
Q/Q
av
21
2. Low Head Turbine Project (2004-7)
CFD, lab and field testing Conclusions:
- Good efficiency if -
the turbine is designed to minimise losses
the turbine is designed to match the site flow
(blade angles are more important than blade cross-section)
air entrainment is avoided
Laser used for velocity measurements in a 200W turbine
4 kW prototype
Prototype 1 kW propeller
22
Pico hydro electrical system
Excitation
Capacitors
User Loads
(+ battery charger)
Ballast Load
(heater)
Induction
Generator
Controller
Induction Generator
• The IGC can be locally made
• “Load limiters” can be used to
prevent overloading
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3. Costs of Solar Home System
Assume 5 hours
peak sun/day
Output is 500 Wh
per day.
3,650 kWh over 20
years
Cost:
$4,200/3650
= $1.15/kWh
Data from:
BuildAfrica.com
24
4. Lighting: LED-halogen comparison
1
10
100
1000
10000
-100.0 0.0 100.0 200.0 300.0 400.0 500.0
distance from peak along plane (mm)
E (
lux)
at
50
0 m
m
"superbright" 12V LED
20W 12V Halogen
A 1.5 W LED cluster claims to be “equivalent” to a 20 W halogen lamp!
Powering a 12V LED lamp through a mains transformer can half the efficiency.
3000
500
