ADB FINESSE Training Course on Renewable Energy

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ADB FINESSE Training Course on Renewable Energy
Energy Efficiency for Poverty Reduction

• 19th 23rd June 2006
• Nairobi, Kenya

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Module 6Small Hydro

• Divas B. Basnyat

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Contents

• Introduction
• Definition
• Fundamentals and Principles
• Small hydro in Africa
• Applications of small hydro
• Barriers to development and implementation
• Design Aids
• Case study - Nepal

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Introduction

• Small hydro for isolated grid, central grid and
  dedicated supply
• Minimum environmental impacts mainly thru run of
  river schemes
• Widely used for
• Rural residential lighting, TV, radio and
  telephone
• Rural small industries, agriculture and other
  productive use
• Grid based power generation
• Reliable, low operating costs, independent of
  energy price volatality

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Hydro Scheme
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Definition size
Source http//www.microhydropower.net/size
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Definition (flow, runner dia)

• RETScreen International

• Less than 5 kW - Pico

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Fundamental and Principles

• Hydropower generation process
• Relationship between power, flow and head
• Types of hydro projects
• Main components
• Power/energy calculations

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Hydro Power Process

• Potential energy of flowing water converted to
  kinetic energy as it travels thru the penstock
• Kinetic energy of the flowing water is converted
  to mechanical energy as it turn the turbines
• Mechanical energy of the rotating turbine is
  converted to electrical energy as the turbine
  shaft rotates the generator

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Power f(Q,H)

• P ???g QH
• P power in Watts
• ? efficiency (micro 50-60, small gt 80)
• ? density of water (1000 kg/m3)
• g acceleration due to gravity (9.81 m/s2)
• Q flow passing thru the turbine (m3/s)
• H head or drop of water (m) (difference between
  forebay level and turbine level or tail water
  level)
• Considering ? 80
• P 8QH kW (approx)

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Small Hydro - Types

• Type of grid
• Central grid
• Isolated or off-grid
• Captive or Dedicated supply (e.g. to cement
  factory)
• Type of Regulation
• Run of river (lower firm capacity, power varies
  with flow)
• Run of river with pondage (some daily peaking)
• Reservoir type (higher firm power, larger area
  inundated)
• Pumped storage (utilizing off-peak energy to pump
  water, less likely in small scale)

Sketch Source BHA, 2005
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Component Civil Works

• Typically account for 50-60 of initial costs
• Diversion dam or weir
• Low dam of simple construction for run-of-river
• Concrete, wood, masonry
• Water conveyance
• Intake with trashrack and gate tailrace at exit
• Sediment handling structure
• Excavated canal, underground tunnel and/or
  penstock
• Valves/gates at turbine entrance/exit, for
  maintenance
• Power house
• Houses turbine, mechanical, and electrical
  equipment

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Turbines

• In run-of-river, flow rate is quite variable
• Turbine should function well over a range of flow
  rates
  or multiple turbines should be used
• Reaction Francis, fixed pitch propeller, Kaplan
• For low to medium head applications
• Submerged turbine uses water pressure and kinetic
  energy
• Impulse Pelton, Turgo, crossflow
• For high head applications
• Uses kinetic energy of a high speed jet of water

Source BHA, 2005
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Turbines
Pelton
Francis
Kaplan
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Electrical and other equipment

• Generator
• Induction used to supply to large grid
• Synchronous stand-alone and isolated-grid
  applications
• Other equipment
• Speed increaser to match turbine to generator
• Valves, electronic controls, protection devices
• Transformer

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Power/Energy Calculation

• Flow Duration Curves annual and monthly
• Compensation flow
• Downstream release (environmental flow)
• Irrigation requirement (if any)
• Leakage
• Design head
• Head losses headworks, headrace, penstock
• Example Design flow 4.58 m3/s, Gross head
  245m, ? 85, Outage 10

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Flow Duration Curve
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Example- Calculation
Power Duration
Monthly Energy
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Head Works-River Diversion
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Settling Basin
Headrace Canal
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Tunnel
Penstock
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Fish Ladder
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Small Hydro Utilization in Africa
Source Karekezi and Kithyoma, 2005
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Tea and Small Hydro in East Africa

• To reduce the electrical energy in the tea
  processing industries in countries

Source http//greeningtea.unep.org.
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Uganda

• Hydro installed capacity 320MW (only 16.7 MW
  small)
• 1 electrification in rural areas
• Mini hydro sites (non-Nile) 200 MW identified
• Can benefit from CDM

Source Taylor and Upadhaya, 2005
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Application- Electricity Generation

• Domestic Load
• Number of households
• Electrical items in all households (light, TV,
  Radio)
• Industrial/Commercial Load
• Agro processing
• Small enterprises
• Shops
• Social Load
• School, Health post etc.
• Others

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Electricity Demand- Isolated
Peak Demand
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Electricity Demand- Central Grid
Source Nepal Electricity Authority
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Application Mechanical Power

• Lift irrigation, water supply
• Agro processing - grain milling
• Saw milling, lathe machine

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Water Mills
Traditional Water Mills
Improved Water Mill (IWM)
Paddy hulling with IWM
Source AEPC
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Barriers

• High initial costs
• Competition on investment from other sectors of
  the economy
• Institutional shortcomings
• Lack of coherent policy framework
• Monopolistic role of national power utilities
• Human Resources Requirements local capability
• Infrastructure constraints- access road,
  transmission line
• Risks for developer and lending agencies
• Time and cost over-run

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Design Aids
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Nepal Case Study
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Nepal Case Study- Contents

• Potential and status
• Hydropower Development Policy
• Small Hydro Project (SHP) Financing Modalities
• Investment scenario
• Barriers and Constraints
• Reform Process
• Examples SHP Implementation

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Potential and Status

• Potential
• Theoretical potential 83,000 MW
• Economical potential 42,000 MW
• 727,000 GWh/year based on average flow
• 145,900 GWh/year based on 95 exceedance flow
• Status
• Current hydro capacity over 600 MW
• About 15 below 10 MW
• In addition, 14.6 MW of MH (1-100 kW, 2200
  schemes upto 2003)
• 25,000 traditional water mills (0.5kW each)

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SHP Financing Modalities

• Donor assisted concessional loans presently
  only for large hydro
• International private companies with commercial
  loan
• National private companies with local commercial
  loan
• National Utility (NEA) through local commercial
  loans mainly between gt5MW)
• Government/donor support agencies like AEPC
  provide subsidy and technical support for micro
  hydro development

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Cost Composition
National Electric Utility
International Private
National Private Sector
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Average Cost Past Projects

• Public sector, donor concessionary projects (60MW
  144 MW) - 3,100 5,600/kW
• Intl private sector with intl commercial
  financing (36 MW and 60 MW) - 2,400 - 2,800/kW
• Local Pvt. Sector with local currency funding
  (3MW project Piluwa) - 1,450/kW
• Micro Hydro (lt100kW) - 1,982/kW

Nepali investment - showing the way to lower
energy prices
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Nepal- Investment Scenario

• 7 projects (55MW) completed thru commercial
  credit from local banks (60m), technical support
  by I/NGOs, Aid Agencies (e.g. WINROCK, USAID,
  GTZ)
• Local banks and financial institutions
  (30m/year)
• Power bonds
• Power development fund (30m )
• For 1-100 kW- subsidy provided by AEPC

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Power Development Fund

• Initial capital of US 35 million by Gov. of
  Nepal and the World Bank (WB)
• To provide project finance core funding to
  supplement private sector
• Partially finance up to 60 of lt 10 MW hydropower
  projects and up to 40 gt 10 MW

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Barriers and Constraints Faced

• Institutional Framework - unclear and overlapping
  roles and responsibilities of existing
  institutions
• Inadequate internal financial resources including
  mechanisms for its mobilizations on account of a
  capital market
• Inconsistencies and conflicts in various
  acts/policies/ regulations
• Shortcomings in the compliance of acts and
  regulations
• Political risk and the adverse situation for
  investment
• Market risk
• License holding by IPPs
• Shortage of a specialized human resource in
  financial institutions with professional
  expertise to appraise, implement and monitor
  hydropower projects
• Isolated rural communities/loads (low load factor)

Source IPPAN, 2004
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Reform Process

• Hydropower Policy (1992, 2001)
• New Electricity Act - unbundling
• Rural Energy Policy (2006)
• Electricity supply- 12 from isolated
  (micro/small) hydro systems, 3 from alternate
  sources
• Community Electricity Distribution Bye-law (2003)
• Rural Electric Entities (REEs) bulk power from
  NEA, CBOs/NGOs own manage distribution
• 80 grant from government, 20 community
  participation

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Reform Process (contd)

• Market risks addressed by PPA
• Support for pre-investment (cost sharing)
• Due diligence training to financial institutions
• Public private complementarities
• Local financing of hydropower projects- local
  FIs, employee provident funds, army welfare funds
• Public Sector multipurpose, larger projects and
  transmission line

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Hydropower Policy - 2001

• Drivers
• Increase access to electricity contribute
  towards energy security
• Stimulate economic growth
• Attract private investment
• Facilitate power trade
• Incentives
• No license required for SHP up to 1 MW
• No royalty imposed for SHP up to 1 MW
• Rs 100 (1.4)/kW 1.75 energy royalty for 15
  years and Rs 1000 (14)/kW 10 energy royalty
  thereafter
• 1 royalty to village development committees
• Policy/reform measures in the offing
• Unbundling of national power utility (NEA)
• Handing over of small hydro to communities and
  private sector by NEA

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SHP Policy

• Fixed buy back rate (up to 5 MW)
• Rs 3.00 (0.04) for wet seasons (mid Apr. mid
  Nov.)
• Rs 4.25 (0.057) for dry seasons (mid Nov. mid
  Apr.)
• 6 annual escalation for the first 5 years
• from Q90 design flow was reduced Q65
• For 5MW 10 MW at (competitive) negotiated
  price basis

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SHP Examples
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Improved Water Mill
Turbine Mill

• Micro Hydro
• 63 community owned
• 37 privately owned
• About 9.2 HH/kW

Data source- AEPC (2005)
Micro Hydro
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Piluwa Khola1

• Installed Capacity 3 MW
• Plant Load Factor 74.4
• PPA Signed on 2000 Jan.
• Contract energy 19.54 GWh
• Dry months 4.89 GWh (25)
• Wet months 14.65 GWh (75)
• Production Started 2003 Sep.
• Commercial Operation 2003 Oct
• Company Established in March 1997

1 Source Pandey, 2005
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Piluwa Khola

• Total cost 4.6 m
• Cost/kW 1462 /kW
• Consortium financing
• Loan from local banks - 56
• Equity 35
• Bridge gap loan 9

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Piluwa Khola

• Nepal Electricity Authority pays the bill of the
  purchased energy every month with a time lag of
  35 days.
• The payment comes directly to the lead bank
  account. The bank deducts the principal and
  interest of the loan from the payment.
• The company gets remaining balance if there is
  something left over.

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Jhankre Mini Hydro2

• 500 kW plant with H 180m Design Q450l/s
• Intake shared with Farmer Managed Irrigation
  Project 13 ha (conflict in operation)
• Owner Khimti Power developer
• Now being handed over to community
• Plant built to replace diesel generators during
  construction of Khimti Project (60MW)
• After Completion of Khimti- for rural
  electrification (5000 HH supplied)

2 Source Karki, 2004
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Jhankre Power Sharing Agreement

• Temporary irrigation supply during construction
• Hydro developer to refurbish irrigation canal
• Employment priority to local
• Existing irrigation water requirements for wheat,
  rice seedlings and rice prioritized

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Thank You