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RbD Subgroup Dean Johnson 8 th April 2008. Agenda. RbD Verification Update Presentation of updated analysis Discussion of declining DMP sample Options available RbD Forecasting. RbD Verification Analysis. Per DMP Customer: Cumulative Billed, Actual & Difference (Billed-Actual).
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Agenda • RbD Verification Update • Presentation of updated analysis • Discussion of declining DMP sample • Options available • RbD Forecasting
RbD Verification Analysis Per DMP Customer: Cumulative Billed, Actual & Difference (Billed-Actual) • Analysis period reflective of MOD152V timescales (Apr-04 to Mar-08) • Trend – avg. cumulative over bill per DMP customer of 1,293 kWh for the period (323 / year) • BUT: Recent trend indicates an under bill per SSP customer (cumulative difference) • Pending analysis and receipt of further reconciliation and DMP data (up to 6 months)
RbD Imbalance – Causes Billed-Actual Difference 4 Year History (April 2004 to March 2008) • Items removed or adjusted to reflect the amended analysis period (MOD152: 4 years)
RbD Imbalance Summary Comparison: Mar08 / Sep07 / Feb07 • Imbalance current 15.76 TWH - reduction from previous (21.64TWH – September 07)
Declining DMP Sample Size Feb98 10,689 Jan08 5,094 • BGT DMP sample utilised in RbD Verification process from February 1998 • 50% reduction in sample size since DMP inception • Significant reduction since 2004, more apparent in last 1 to 2 years • Potential issues regarding confidence in RbD verification results…
Declining DMP Sample Size • DMP sample of 10,000 meter points represents a 0.95% margin of error • i.e. The results presented are accurate to within +/- 0.95%, 95% of the time • Current DMP sample size is 5,094 • Represents 1.37% margin of error • DMP sample is imperative to the RbD verification process • Confidence in results not currently regarded as an issue • BUT – sample reduction needs to be addressed and maintained going forward • Additional interest is being placed on verification results • Headings quoted - MOD194 ‘Correct Apportionment of NDM Error – Energy’ • xoserve & BGT have discussed the DMP sample issues • Options are available to address the declining DMP sample numbers…
Declining DMP Sample Size: Options • Option 1: BGT to boost DMP sample numbers • BGT solely responsible boost and maintain going forward • Option 2: Additional Shipper involvement • Additional samples from customer base, replicate BGT established process • Option 3: Do nothing • Sample numbers still good, error margin good, but sustainable? • Option 4: Transporters / xoserve run own DMP sample • Central operation and maintenance • Option 5: Combine DMP with Demand Estimation data recorder sample • Established sample - 3,440 data recorders currently installed on SSP sites • Manual collection twice a year – used in deriving NDM Algorithms for allocation • Combined; 8,600 sample (1.06% margin of error) • Available data allows initial analysis - indicates following results…
Declining DMP Sample Size: Data Recorders Cumulative Billed, Actual & Difference (Billed-Actual) Per DR Customer • Identify billed values and actual value for recorders (replicate DMP analysis) • Data recorder analysis shows a different trend to DMP • DMP indicates SSP Billed >Actual (over): DR indicates SSP Billed < Actual (under) • Further investigation required, data available May
DMP Sample Size – Declining: Options • RbD Sub Group to consider options: • Option 1: BGT to boost DMP sample numbers • Option 2: Additional Shipper involvement • Option 3: Do nothing • Option 4: Transporters / xoserve run own DMP sample • Option 5: Combine DMP with Demand Estimation datarecorder sample