Micro-hydro applications in rural areas

Transcription

1 OASYS South Asia: Dundee Workshop 20 Micro-hydro applications in rural areas Dr Arthur Williams Dept. of Electrical & Electronic Engineering University of Nottingham, UK Types of hydropower Conventional hydropower usually uses a reservoir (Llyn Brianne, Wales: 4 MW) <0 MW is called Small hydro Micro hydro is usually Run-of-river Pico hydro in SE Asia (< kw) (Las Juntas, Peru: 2 kw) 2

2 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 AKRSP, Pakistan Many good sites in remote rural areas 3 Rural Electrification Options Grid Connection too expensive unreliable, especially in mountainous areas Stand-alone options rechargeable batteries Solar Home Systems Mini-grid options diesel generators Pico Hydro Kushadevi - Nepal - site of a 3 kw Pico Hydro project 4

3 Magdalena, Peru Petrol or Diesel Solar PV Type of Generator PV-Wind hybrid Wind Pico hydro Rural Electrification Options 2006 World Bank study: Off-grid Costs W 300 W Minimum Lower Range Probable Range Higher Range 2002 study in Kenya: PH: PV: >$ 300 W W W Predicted Cost in 200 (UScent/kWh) Civil works for pico hydro Simple intake structures Storage only for evening use in dry season Minimal use of cement Kathamba, Kenya For higher head schemes, Polyethylene or PVC pipe is easily available and light to transport. 6

4 Leverhulme Project, Nott m Trent University Pico hydro turbine types For higher heads: locally manufactured Pelton turbine For medium heads: crossflow or pump as turbine - imported or locally made - also uses induction motor as generator Thailand: project of Border Green Energy 7 Pico hydro turbine types For low heads: propeller turbine (with scroll casing or open flume) Kathmandu University 8

5 Village hydro cost breakdown 24% Relative Cost 4% 8% Civil works Penstock 4% 22% Turbine,Gen.+Control Cable+Lamps Wiring labour Design+Management 38% Average % costs for Kenyan schemes (200) Note: No battery costs 9 Balancing costs and efficiency Max. Voltage Drop % 0% Cable Cost 2,000,600 Power delivered to Consumers Total Scheme Cost ( kw scheme) Cost per power delivered 0.97 kw 0.94 kw,000 4,600,/kW 4,894/kW (-%) Reducing cable thickness saves on cost/kw - but there is a limit to acceptable volt drop (ΔV) 0

6 Z Turbine House Z3 Z2 u p S u T Intake ZCc Cb 4 Ca Z 3 7Z 3Z Z8 4Z Z 6Z Z Z7 3 3 Z6 3 Z 3 Z0 Z Z3 3 Z4 3 Cr d B Z 2 Z4 a B Z3 2 Z4 2 Z0 2 Z9 0 c B Z8 Z6 Bb 9Z 7 8 Z 2 Z2 C Z6 2 6 Z9 4 Z 4 Z3 4 Z2 4 Z0 6 Z4 4 Z6 4 Z9 3 Z 4 Z7 Z8 2 2Z 4 3 Ar 4 2 e s u o h e ni u p S br A typical village layout (Kathamba, Kenya). Most spurs have several branches Houses are clustered. Load limiters used. Cb 4 Ca Cr u T 27Z 26Z 2Z 60Z a B 7Z Z Br 3Z s n e P 20Z 9Z 0 3Z 34Z c B d B s ert e m0 0 49Z 2 32Z 3Z 29Z 30Z 2Z 28Z 24Z 23Z 7 2Z 8Z 7Z 6 4Z Z 3Z 6Z 8 2Z 0C C 6 7 Bb u p S 48Z 9 to 38Z 39Z Cc 8 40Z k c 4Z 43Z 8Z 9 37Z 42Z 36Z Be0Z u p S Br Be Z0 Z8 4 4Z 46Z 3 9Z 4Z u p S Z C0 4Z 9Z 8Z Z2 2 Z7 2 Z8 2 Z Z4 Z3 Z7 2Z Ar 3Z 3 4Z Z 6Z Z9 2 3 Z 2 2 8Z 4 7Z 2 2Z e s 3Z u p S u o h e ni r e iv br R ia r e g n e k u M ViPOR program applied to Kathamba layout No cable across valley

7 Cable selection program (v.2) (under development) Spurs and branches; Accurate positioning; Variable loads. 3 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. 4

8 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 Conclusions - lighting LED v CFL Photo Source: LUTW V. low power; narrow beam; v. long life; Efficient for LV systems Low power; wide beam; higher efficacy; long life; Better for mains voltages. 6

9 Dissemination Support for local entrepreneurs: Local manufacture of turbines. Photo: Phil Maher, Pico Energy Ltd. Management models, Peru Practical Action have useful publications 7 On-line information for Pico 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 8

10 Q/Qav Conclusions Village-based mini-grids are suitable for rural electrification Renewable energy based systems are cost-effective (esp. hydro) Costs can be reduced through:. local manufacture 2. using PC-based design for turbines, pipes and distribution cables Photo Source: LUTW Compared with kerosene lamps or dry-cell torches, Electric lighting is Cheaper Cleaner Safer December 200: Zhiture, one of two new Microhydro plants installed by AKRSP in Chitral, Pakistan. 9 Extra slides:. Water flow variation Flow available will vary with seasons and from year to year. Available flow is shown by a flow duration curve. Q av is (rainfall - evaporation) catchment area. Without storage, a hydropower plant will be sized to use a flow rate < Q av. Flow duration curve Probability 20

11 2. Low Head Turbine Project (2004-7) Laser used for velocity measurements in a 200W turbine 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 crosssection) air entrainment is avoided Prototype kw propeller 4 kw prototype 2 Pico hydro electrical system Induction Generator Excitation Capacitors Induction Generator Controller User Loads (+ battery charger) Ballast Load (heater) The IGC can be locally made Load limiters can be used to prevent overloading 22

12 E (lux) at 00 mm 3. Costs of Solar Home System Assume hours peak sun/day Output is 00 Wh per day. 3,60 kwh over 20 years Cost: $4,200/360 = $./kwh Data from: BuildAfrica.com Lighting: LED-halogen comparison "superbright" 2V LED 20W 2V Halogen distance from peak along plane (mm) A. W LED cluster claims to be equivalent to a 20 W halogen lamp! Powering a 2V LED lamp through a mains transformer can half the efficiency. 24