Stratification

1
Stratification Sampling of Electricity Consumer
Data forOutage Cost Determination
Daniel Andrew Sen (SE 20240) 10 July 2007
2
Project Overview

• Customer Requirements
• To calculate the VoLL for the Malaysian
  Electricity Supply Industry
• Aims Objectives
• To determine the outage costs
• To determine weightings of each customer class
• To compute the Malaysian VoLL

• Project Background
• This research is Phase I, which ran for 13
  months. It is limited to finding the system wide
  outage cost (OC)
• In Phase II, the Reliability Cost can be
  determined
• In Phase III, the TC Curve can be determined.
  Then, system reliability can be optimized
• Deliverables
• A complete methodology on determining the VoLL
• Grouping of consumers based on their energy
  demand
• A questionnaire which allows TNB to quickly
  assess the outage cost to consumer
• Data on outage costs over the range of consumers
  investigated
• The Value of Loss Load

3
Research Methodology
4
Research Methodology

• Definitions
• Customer Outage Cost the economic cost to
  customers following a loss of supply. This can
  can include the cost of wasted raw material,
  labour, time, contractual loss, prestige etc.
• Reliability Cost investments or operational
  cost spent to increase the level of network
  reliability
• Value of Loss Load is an aggregated economic
  cost from a group of customers following a loss
  of supply.

5
Research Methodology

• Literature Survey
• Assumptions
• Accounting Cost vs. Economic Cost (tangible costs
  only)
• Fixed Environment (outages assessed occur at
  typical times and load levels)
• Questionnaire Development
• Based on EPRI model
• Questionnaire is then Malaysianised (e.g. no
  winter data required, no postal feedback done)

6
Research Methodology Customer Weighting

• Customer Weights
• TNB Billing Data
• Computation of VoLL
• Based on Energy Consumption (EPRI study) and not
  on peak load
• peaking load will not reflect weighting correctly
  as it is temporary
• Important to reflect each customers influence on
  the overall VoLL
• Based on
• Customer Type
• Domestic
• Commercial
• Industrial

7
Research Findings Domestic Stratification

• Domestic Strata
• Bungalow
• High-rise
• Kampong
• Terrace

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Research Findings Commercial Stratification

• Commercial Strata
• Accommodation
• Agriculture
• Communication
• Construction
• Financial Institution
• Insurance
• Real Estate/Business Services

• Recreation
• Residential Shop House
• Retail
• Social Services
• Transport
• Wholesale
• Others

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Research Findings Industrial Stratification

• Industrial Strata
• Electrical Electronics
• Paper, Printing Publishing
• Chemical Petrochemical
• Iron Steel
• Non-ferrous Metal
• Transport Equipment
• Food
• Wood
• Textiles

• Clay-based Non-metallic
• Plastics
• Rubber
• Tobacco
• Furniture Fixtures
• Palm Oil Palm Kernel Oil
• Pharmaceuticals
• Machinery
• Others

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Research Methodology VoLL Calculations

• Generalized formula
• where
• a is customer weighting
• n is number of strata
• Custn is losses incurred by customer n

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Research Findings VoLL Calculations

• Specific formula for Domestic VoLL
• where
• VoLLD is the composite VoLL for all domestic
  strata
• VoLLDn is the VoLL of the nth domestic stratum
• kWhDn is the kWh consumption for the nth domestic
  stratum
• nD is the integer number of domestic strata

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Research Findings VoLL Calculations

• Specific formula for Commercial VoLL
• where
• VoLLD is the composite VoLL for all commercial
  strata
• VoLLDn is the VoLL of the nth commercial stratum
• kWhDn is the kWh consumption for the nth
  commercial stratum
• n is the integer number of commercial strata

13
Research Findings VoLL Calculations

• Specific formula for Industrial VoLL
• where
• VoLLD is the composite VoLL for all industrial
  strata
• VoLLDn is the VoLL of the nth industrial stratum
• kWhDn is the kWh consumption for the nth
  industrial stratum
• n is the integer number of industrial strata

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Research Findings VoLL Calculations

• Specific formula for Composite VoLL
• where
• VoLLmy is the composite VoLL for Peninsular
  Malaysia
• VoLLD is the composite VoLL for all domestic
  strata
• VoLLC is the composite VoLL for all commercial
  strata
• VoLLI is the composite VoLL for all industrial
  strata
• kWhmy is the kWh consumption for the Peninsular
  Malaysia
• kWhD is the kWh consumption for the nth domestic
  stratum
• kWhC is the kWh consumption for the nth
  commercial stratum
• kWhI is the kWh consumption for the nth
  industrial stratum
• n is the integer number of consumer groups

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Composite VoLL
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Conclusion

• Stratification process allows accurate
  representation of Peninsular Malaysia electricity
  customers demographics
• The VoLL for Peninsular Malaysia is RM22.72/kWh
  interrupted for a one hour power outage

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• The End