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- Gerald B. Sheblé and Daniel Berleant
- Dept. of Electrical and Computer Engineering
- Iowa State University
- Ames, Iowa 50011
- USA
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- Energy service company background
- ESCO = Energy Service COmpany
- ESCOs are electric power retailers
- Traditionally, rates are set by a regulator
- Increasingly, deregulation is occurring
- Market forces are now driving competition
- A new risk is the risk of going out of business
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- Value at Risk = VaR
- VaR consists of
- an upper limit on acceptable financial loss
- p(loss will be within the acceptable limit)
- The limit might be
- how much the company can lose, and
- still stay in business
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- Deregulated energy service companies…
- are operating in a “typical” competitive mode
- and must understand and control their VaR
- A model of VaR for ESCOs is needed
- To reliably analyze it, we propose to:
- avoid assuming components are independent
- use an interval-based analysis algorithm, DEnv
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- Covariance method is relatively fast, easy
- It requires a correlation matrix
- (for the uncertain factors)
- It assumes the uncertain factors are Gaussian
- This assumption is not always valid
- Invalid assumptions lead to incorrect conclusions
- An augmented or different method is needed
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- Relies on historical data as problem input
- But historical data may be insufficient, and
- The current environment may have changed
- The historical approach is not always best
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- MC involves randomly generating events
- Events are derived from distribution functions
- Distributions are often assumed normal
- (But they don’t have to be)
- Distributions are often assumed independent
- (But they don’t have to be)
- MC is tricky when dependencies among distributions cannot be assigned
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- We combine three contributors to risk:
- 1) Market Price Risk
- Price fluctuation can cause losses in any business
- 2) Supplier Contract Failure
- The ESCO’s energy suppliers may not deliver
- 3) ESCO Contract Default
- The ESCO itself may be unable to deliver
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- Uses a covariance matrix of fluctuations
- This may be derived from historical data
- VaR of market price fluctuation is:
- P is proportion of overall value of...
- is the volatility (determines
confidence)
- C is the covariance matrix
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- Failures may be the fault of
- GENCOs (generating companies)
- TRANSCOs (transmission companies)
- DISTCOs (distribution companies)
- ICA (Independent Contract Authority)
- This 2nd VaR component contributes to
- losses due to ENS (energy not served) model
- the 3rd VaR component also contributes to
- loss due to ENS...
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- ESCOs (Energy Service Companies) may
- fail to deliver due to supplier failures
- fail to deliver due to operational failures
- Major operational failure sources are
- human error
- computer error
- strategic error
- Operational risk combines those sources
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- Power undelivered to customer due to
- Operational failure of the ESCO
- Failure of suppliers to deliver to the ESCO
- Supply chain includes
- GENCOs
- TRANSCOs
- DISTCOs
- Coordinators
- ESCO
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- (Recall ESCO is the energy retailer)
- Most obviously, there is loss of income
- Failure to deliver may incur a penalty
- Customer should be compensated
- (This may be via rebate or direct payment)
- Compensation should account for:
- damage to the customer, and
- need by ESCO to retain the customer
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- Any link in the supply chain to the ESCO
- ...may cause a failure of supply
- ...and result in compensation TO the ESCO
- The ESCO may suffer operational failure
- ...resulting in payments to the customers
- Note no standards for this exist yet
- ESCOs should have a capital fund for this
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- Energy sales depend on supply contracts
- Contracts may be spot, forward, or futures
- Contracts are made by a double auction system
- Astute bidding strategies are a necessity
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- Step 1: get a PDF for each factor
- Step 2: obtain the PDF for
- the sum of the factors
- That is, given random variables,
- what is the distribution of their sum?
- Complication:
- The factors are not independent
- Worse, we don’t know their dependency
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- Strengthen effects of constraints due to partial information about
dependency
- Address calculation of individual components
- Continue to develop applications of an interval-based algorithm, DEnv
- Questions?
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