Transcript Introduction to Microhydro 15 Apr 2012 Monterey Institute for International Studies Chris Greacen [email protected].

Introduction to Microhydro
15 Apr 2012
Monterey Institute for International Studies
Chris Greacen
[email protected]
Outline
• Micro-hydro system overview
• Site assessment
– Head
– Flow
• Civil works
• Mechanical
• Electrical
Sun, Wind, & Water
Financial analysis pico-hydropower
US Dollar per hh/year
350
300
250
200
150
100
50
0
Pico-hydro
(Laos)
Mattijs, Smits, presentation at
Chulalungkorn University
Pico-hydro Community Solar home Diesel/petrol
(Vietnam) pico-hydro
system
gensets
4
ESMAP,
2005
Micro-hydroelectricity: Estimating the
energy available
Power = 5 x height x flow
height
Watts
meters
liters per
second
Image Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Measuring height drop (head)
• Abney level
• Site level
• Pressure gauge
Abney level
(the method we’ll be using today)
Sight level method
Hose & Pressure Gauge
•
•
•
•
•
Accurate and simple method.
Bubbles in hose cause errors.
Gauge must have suitable scale and be calibrated.
Use hose a measuring tape for penstock length.
Feet head = PSI x 2.31
H1
Measuring Flow
• Bucket Method
• Float Method
design flow = 50% of dry-season flow
Bucket Method
(probably the method we’ll be using today)
Float Method
Flow = area x average stream velocity
Civil Works – some golden rules
• Think floods,
landslides
• Think dry-season.
• Try to remove
sediment
• Maximize head,
minimize penstock
– “wire is cheaper than
pipe”
Image source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Weir
A Sluice allows sediment removal.
Locating the Weir
& Intake
Silt Basin
Trash Rack
Intake
Head Race
Weir
Penstock
Side intake
Screens
• Screen mesh-size should be half the nozzle diameter.
• A self-cleaning screen design is best.
• The screen area must be relatively large.
Screen
Head Race
Silt Basin
Penstock
Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Power Canal (Head Race)
• It may be less expensive to run low pressure
pipe or a channel to a short penstock.
Head Race
6” Penstock
4” Penstock
Forebay (Silt basin)
• Located before penstock
• Large cross-sectional area, volume  Water velocity reduced 
sediment (heavier than water but easily entrained in flow) has
opportunity to drop out.
Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Penstocks
• A vent prevents vacuum collapse of the penstock.
• Valves that close slowly prevent water hammer.
• Anchor block – prevents penstock from moving
Vent
Valve
Pressure Gauge
Valve
Anchor Block
Penstock
Penstock diameter
Hazen-Williams friction loss equation:
• C = roughness coefficient
Penstock materials
•
•
•
•
Poly vinyl chloride (PVC)
Polyethylene (PE)
Aluminium
Steel
Anchor and Thrust Blocks
Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.
Locating the Powerhouse
•
•
•
Power house must be above flood height.
Locate powerhouse on inside of stream bends.
Use natural features for protection.
Micro-hydro technology
Pelton
Turgo
Crossflow
Kaplan
Centrifugal
pump
Turbine application
http://www.tycoflowcontrol.com.au/pumping/welcome_to_pumping_and_irrigation/home4/hydro_turbines/turbine_selection (April 18, 2003)
Efficiency and Flow
100%
Efficiency
Pelton and Turgo
Crossflow
Propeller
50%
Francis
0%
0
0.2
0.4
0.6
0.8
Fraction of Maximum Flow
1.0
Generators
• Permanent magnet
• Wound rotor synchronous
• Induction (Asynchronous)
Thank you
For more information, please contact
[email protected]
This presentation available at:
www.palangthai.org/docs