Indonesia Clean Energy Development Project (ICED) Lessons Learned - - PowerPoint PPT Presentation

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Indonesia Clean Energy Development Project (ICED) Lessons Learned - - PowerPoint PPT Presentation

Nov 20, 2022 14 likes •498 views

Indonesia Clean Energy Development Project (ICED) Lessons Learned Development, Construction and Operations MHP in Indonesia June 2014 1a Common Problems/Lessons Learned Hydrology and Energy Project Layout Water Conveyance Construction

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Indonesia Clean Energy Development Project (ICED)

Lessons Learned Development, Construction and Operations MHP in Indonesia

June 2014

1a

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Common Problems/Lessons Learned

Hydrology and Energy Project Layout Water Conveyance Construction Problems Contracting and Risk Allocation Operations Experiences

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Hydrology and Energy – PROBLEMS

Daily versus Monthly or Periodic Averages Analysis too simple Estimates of losses Grid stability? Water conveyance? Efficiency Estimates

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The Importance of Daily Flow Analysis

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Hydrology and Energy SOLUTIONS

Use method for energy not dam construction or irrigation Analysis too simple- Use details Need to test hydrology Run actual daily data with specific losses and efficiency Estimates of losses Grid stability? Water conveyance? Efficiency Estimates

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Project Layout Potential power abandoned due to layout of : Powerhouse Intake Flushing gates Desanders Velocity and Hydraulic Losses Head Pond Hydraulics Tailrace Construction

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Project Layout – Powerhouse Elevation PROBLEM – Design sacrifices head and energy

Most projects are Francis Turbines Applications Frequently, an open powerhouse in a horizontal orientation is designed Well above tailwater Well above flood level Barrier is placed in tailrace to provide backwater pressure More efficient layout is “Vertical Powerhouse” Equipment is placed in a pit, well below powerhouse openings River tailwater sets the back water level Gates used to isolate

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Example of Vertical Orientation Powerhouse

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Project Layout – PROBLEM Intake Design

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Project Layout - Problems with Intake PROBLEM – DEBRIS PROBLEMS AND HEAD LOSS Make entire river make a right turn Enter Gates Make another right turn Adjacent to flushing- All debris pulled towards Power Intake

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Project Layout – Proposed Intake Improvements SOLUTIONS: Open up intake to river with lower velocity Keep intake above river bottom as possible Keep higher than flushing gates Use tainter gate for flushing Avoid “bending flow as possible

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Project Layout - Flushing Gates PROBLEM – INADEQUATE FLUSHING AND DAMAGE Standard is Leaf or Sluice gate Usually too small and not strong Gates Jam or get damaged Debris is not passed

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Project Layout - Flushing Gates SOLUTIONS?

  • Use tainter gate if possible
  • Double gating for sluice or leaf gates
  • Provide for stop logs
  • Use multiple gates and large gates

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Tainter Gate

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Project Layout – Silt Chambers or Desanders PROBLEM – High Cost – Questionable Value Not all projects need them They are expensive Primary use – keep sand and abrasive material from the turbine What is at risk? Runner and seal wear in the turbine

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Project Layout – Silt Chambers or Desanders SOLUTIONS: ASK - Do you need one at all? Is sand present? Will proposed structure remove it? Is it less expensive to have turbine spares? Use the diversion pond as primary desander Use a head pond as secondary desander

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Layout: Flow Velocity and Losses PROBLEMS: Some velocities in canal and penstock are too high Excessive losses – Unstable flow Surge problems Losses often not correctly calculated Surge relief for penstocks inadequate

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Layout: Flow Velocity and Losses SOLUTIONS Pay strict attention to designs Double check hydraulic losses and surge Canal Velocity should be 0.7 m/sec and no more than 1 m/sec Double check any calculations for penstock surge Check Turbine Manufacturer for pressure rises

  • n trips

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Project Layout – Head Pond Hydraulics PROBLEMS:

Head ponds are not designed adequately:

  • Inadequate submergence of penstock opening
  • Hydraulically unfriendly

Result:

  • Vortices
  • “Starved” intakes

= LOST ENERGY

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Project Layout – Head Pond Hydraulics SOLUTIONS:

  • Substantial submergence for penstock inlet
  • Hydraulic transition at penstock intake
  • Large head pond to still flow and maintain operations
  • Have head pond reviewed by experienced hydraulic engineer
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Project Layout – Tailrace Construction PROBLEM:

  • Like Powerhouse – Tailrace well above river level
  • Barrier in tailrace to produce back pressure

Result – Lost potential energy from the site

SOLUTION:

  • Tailrace should be set by river level with gates to shut off

turbines for maintenance and repair.

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WATER CONVEYANCE – Canals, Penstocks, Tunnels PROBLEM: Significant construction cost over runs and other difficulty in constructing canals

  • Excavation Materials unknown
  • Massive cuts without sufficient spoil areas
  • Unstable slopes
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WATER CONVEYANCE – Canals, Penstocks, Tunnels PROBLEM: Significant construction cost over runs and other difficulty in constructing canals

  • Canal Design and Cost Estimates leave out:
  • Geotechnical Exploration
  • Slope Stability
  • Drainage crossing
  • Public safety
  • Foundation stabilization
  • Rock excavation
  • Structural lining
  • Proper Spoil
  • Room for Access Road
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WATER CONVEYANCE – Canals, Penstocks, Tunnels PROBLEM: Canal Dynamics make Complex Operations

  • Flow changes cannot be made quickly
  • Instrumentation is often missing
  • Elevation changes in head pond/canal/intake only

way to change flow

  • Inefficient operations when not at full output
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Project Elements – Diversion and Intake

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WATER CONVEYANCE – Canals, Penstocks, Tunnels SOLUTIONS:

  • Buried Penstocks- reduce cut and slope problems
  • Tunnels where feasible
  • Combination of canal/Tunnel
  • Use all costs in selecting conveyance design
  • Consider operating efficiency
  • Penstocks and tunnels can operate under

pressure and simplify operations

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WATER CONVEYANCE – Canals, Penstocks, Tunnels ADVANTAGES OF PRESSURIZED SYSTEM

  • Only handle/clean water once
  • Eliminate head pond
  • Simplify operations
  • Quick response by system to river change
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WATER CONVEYANCE – Canals, Penstocks, Tunnels DISADVANTAGES OF PRESSURIZED SYSTEM

  • Cost might be higher
  • Surge relief still needed for Francis Turbines
  • Underground works (tunnel) also have

construction risk

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Construction Issues

PROBLEM: Construction Contracts do not Allocate Risk Contractors do not provide fixed cost contracts

  • Project not well defined before “EPC”
  • Owners do not provide detailed information to fix

prices;

  • Owners do not want to pay contractors risk

premium;

  • Cost expectations of projects are not realistic
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Construction Issues

PROBLEM: Construction Contracts do not Allocate Risk

RESULT:

  • Cost Over-Run
  • Schedule delay
  • Changes in middle of construction
  • Disappointing Quality
  • Little control by Owner over Contractor
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Construction Issues

SOLUTIONS – Contracts that Allocate Risk

  • Contractors are in the best position to manage it
  • Sufficient information from the developer is

necessary – more details than now provided

  • Risk Premium included in pricing
  • Negotiations for risk understanding and sharing
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Construction Issues– Environmental Damage

PROBLEM: Poor Protection of Environment

RESULT:

  • Poor practices result in landscape scars
  • Accidents and landslides

SOLUTIONS

  • Diligence on part of Owner’s team
  • Contract for and enforce Environmental

Protection

  • Penalty Clauses
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Construction Issues

SOLUTIONS:

  • Better Project Preparation
  • Analysis of Water Conveyance Options
  • Discussion of Risk Allocation with Contractors
  • Develop proper bid documents that allocate risks
  • Negotiate Risk Sharing
  • Keep Design Engineer involved
  • Site Presence by Owner and Design Engineer
  • Formal Quality Control Program
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Allocating Risk in Civil Contracting In order for an Owner to allocate risk to a Good Contractor:

  • Define EPC clearly
  • Provide a performance specification and

definition

  • Clarify project constraints
  • Substantial topography, cleared areas and good

geotechnical data. EXACTLY WHAT ARE YOU BUYING?

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EQUIPMENT CONTRACTING PROBLEM: Poor E&M Equipment or Controls = Excessive Outage

  • “Project can’t afford expensive equipment”
  • “Instrumentation not necessary”
  • Components and auxiliaries questionable quality
  • High outage rates and marginal efficiencies are

not economic

  • Replacement of equipment prematurely is very

expensive

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EQUIPMENT CONTRACTING SOLUTIONS:

  • Develop relationships with better manufacturers
  • Equipment quality not by country of origin but by

manufacturer

  • If there is any question, go see installation
  • Provide clear specifications of what is needed

including quality

  • Ask for instrumentation to operate plant
  • Know bill of materials before signing the contract
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EQUIPMENT CONTRACTING SOLUTIONS:

  • Buy internationally available components
  • Buy components by manufacturers with

reputations

  • Put instrumentation in the project
  • Automate as possible – it is inexpensive
  • Electronic components continue to get cheaper
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Excitation 1990 Excitation 2012

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OPERATIONS ISSUES

  • Cooling water systems
  • Poor equipment components
  • Limited operation information
  • Grid Connection and Quality
  • High outage rates
  • Spare Parts
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Operations – Cooling Water System PROBLEM: Cooling water system shuts down causing

  • utage
  • Usually once-through cooling water is designed
  • Water is warm and has many micro organisms
  • Filters clog regularly

SOLUTION: Implement a recirculating system from the beginning

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Operations: Poor equipment components PROBLEM: Poor components cause shutdown, high maintenance, damage to other components, questionable efficiency SOLUTIONS:

  • Most post-commissioning problems are painful to

solve

  • Replace poor parts with higher quality
  • Avoid these problems by paying for good value
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Operations: Limited data for Operations PROBLEM: Actually knowing site operation efficiency is impossible SOLUTIONS:

  • Level sensors at key components, diversion,

desander, head pond

  • Instrumentation for pressures and temperatures
  • SCADA system
  • Automation
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Operations: Grid Connection Quality and Issues PROBLEM: High transmission losses and outage rates

  • Voltage and frequency changes
  • Long 20 KV interconnection
  • Generating unit cycling off and on

SOLUTIONS:

  • Interconnection Guidelines
  • Help PLN have a stable line
  • Provide good controls for reaction of generator
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Operations: Spare Parts PROBLEM: Plant outage without proper spares SOLUTIONS:

  • Do risk analysis of components to consider what to

buy

  • Insist on internationally available components
  • Replace spares as used
  • Have suppliers on hand for emergency needs
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SMALL HYDROPOWER SECTOR FIVE UNIQUE OPPORTUNITIES IN INDONESIA

1. Huge resource of good sites 2. Power is needed and

  • ffsetting expensive

power 3. Capital is available 4. Permitting reasonably easy 5. Getting a PPA is relatively simple

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Successful Risk Management = Long Term Asset

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