PacifiCorp IRP Operating Impacts Study Update

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PacifiCorp IRP Operating Impacts Study Update
Planning for Wind Workshop Portland,
Oregon December 3, 2003
Ken Dragoon ken.dragoon_at_pacificorp.com
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Background

• PacifiCorp integrates approximately 300 MW of
  wind generation on system of 8,300 MW capacity
  (3.6).
• At outset of IRP process, wind integration costs
  thought to be small with low penetration, but
  rising in unknown ways with higher installed
  capacity.
• Analysis done for IRP exposed to public comment
  as well as vetting with wind experts in field
  (DeMeo, Milligan, Caldwell, Hirst).
• Analysis suggested costs associated with holding
  additional reserves and system dispatch
  (imbalance costs).

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Imbalance Cost Increases with Installed Wind
Capacity
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Reserve Requirements Increase with Wind Capacity
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Reserve Requirement Cost Formula

• Cw Reserve requirement cost (/MWh)
• Pw Installed wind capacity
• f Wind capacity factor
• A, B constants (B/f 1/MWh)
• Formula assumes cost of reserves increases
  linearly with reserve requirement.

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Site-Specific Integration
Cost Calculation Examples
System Capacity Factor Imbalance
Reserve Total East 500 MW 35
1.75 1.51 3.26 West 500 MW
35 2.10 1.39 3.49 East
1,000 MW 30 3.25 2.72 5.97
West 1,000 MW 30 2.95
2.04 4.99
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IRP Results

• IRP identified 1,400 MW of additional wind
  capacity (14) as part of lowest cost resource
  portfolio over first 10 years of study.
• PacifiCorp expects to release RFP for renewables
  (not just wind) in December.

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Improving on IRP Analysis

• Two pronged approach
• Improve analytical technique
• Improve modeling capability
• Refine hourly sigma analysis
• Address sub-hourly issues
• Address capacity credit question
• Examine actual operating experience
• Operators kept hourly log of wind affects on
  system for couple months earlier this year.

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Value of Wind Forecasts

• Wind output can be forecast
• Not as well as temperature
• Better than precipitation
• PPM Energy sells wind output on a firm basis,
  backed up with cash market transactions and
  options as necessary.
• State of wind generation forecast technology
  rapidly improving.

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Sample Wind Forecast Data
Data courtesy PPM Energy and 3Tier Group
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Logjam Effect

• Initially many severe skeptics-- but experience
  is breeding acceptance.
• Operators beginning to understand that their
  headache with accommodating wind earns money for
  the company.
• Our study is motivating others to pragmatically
  study costs.
• Early studies were long on theory, without
  resulting in actual costs calculations.

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Conclusions

• Getting past analysis paralysis is resulting in
  real resource acquisition.
• Much work to be done to improve the analysis--
  want to keep analysis in touch with operating
  experience.
• Experience has helped wind resource to achieve
  acceptability among operators and managers.
• Wind forecast technology is improving and
  providing significant help in managing wind on
  power systems.

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41 MW Combine Hills Project in NE Oregon