Introduction to Microhydro 15 Apr 2012 Monterey Institute for International Studies

1. Introduction to Microhydro 15 Apr 2012 Monterey Institute for International Studies Chris Greacen chris@palangthai.org

2. Outline • Micro-hydro system overview • Site assessment • Head • Flow • Civil works • Mechanical • Electrical

3. Sun, Wind, & Water

4. Financial analysis pico-hydropower ESMAP, 2005 Mattijs, Smits, presentation at Chulalungkorn University

5. Micro-hydroelectricity: Estimating the energy available Power = 5 x height x flow height meters liters per second Watts Image Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

6. Measuring height drop (head) • Abney level • Site level • Pressure gauge

7. Abney level (the method we’ll be using today)

8. Sight level method

9. 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

10. Measuring Flow • Bucket Method • Float Method design flow = 50% of dry-season flow

11. Bucket Method(probably the method we’ll be using today)

12. Float Method Flow = area x average stream velocity

13. 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.

14. Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

15. Weir A Sluice allows sediment removal.

17. Silt Basin Trash Rack Intake Head Race Penstock Weir Locating the Weir & Intake

19. Side intake

20. 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 Penstock Silt Basin

21. Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

22. 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

25. 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.

26. Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

27. 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 Penstock Anchor Block

28. Penstock diameter Hazen-Williams friction loss equation: • C = roughness coefficient

29. Penstock materials Poly vinyl chloride (PVC) Polyethylene (PE) Aluminium Steel

30. Anchor and Thrust Blocks

31. Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

32. Locating the Powerhouse • Power house must be above flood height. • Locate powerhouse on inside of stream bends. • Use natural features for protection.

33. Micro-hydro technology Centrifugal pump Pelton Turgo Crossflow Kaplan

34. Turbine application http://www.tycoflowcontrol.com.au/pumping/welcome_to_pumping_and_irrigation/home4/hydro_turbines/turbine_selection (April 18, 2003)

35. Efficiency and Flow 100% Pelton and Turgo Crossflow Propeller 50% Efficiency Francis 0% 0 0.2 0.4 0.6 0.8 1.0 Fraction of Maximum Flow

36. Generators • Permanent magnet • Wound rotor synchronous • Induction (Asynchronous)

37. Thank you For more information, please contact chris@palangthai.org This presentation available at: www.palangthai.org/docs