1. Using Load Research Data Analysis to Determine Number of Electric Heating Customers AEIC Load Research Committee Meeting Marco Island, Florida June 10, 2002 Rick A. Voytas Manager-Corporate Analysis Ameren Services

2. Senior Management’s Request A count of residential electric heating customers, and if possible, provide a breakdown by type of electric heat.

3. Three Ways to Track Heating Usage? » Customer Information System »CIS »CSS » Transformer Load Management (TLM) »tracks a “heat code” for each residential meter » AMR System Load Snapshot »gathers a snapshot of individual customer demand during peak time load periods

4. Issues with Obtaining Information From Traditional Sources Customer Information System » Customer Information System »CIS- electric heating codes have not been maintained »CSS- does have an electric heating premise but it is unsupported Transformer Load Management (TLM) » Transformer Load Management (TLM) »does not create heat saturation tape for CIPS »cannot differentiate the different types of electric heating » AMR System Load Snapshot (SLS) » can only be used for AmerenUE customers »cannot differentiate the different types of electric heating

5. Issues with Obtaining Information From Traditional Sources » Both SLS and TLM can be used to track electric heat but Does not cover the whole company (just AmerenUE) and neither has the ability to differentiate the different types of electric heat

6. Let’s Review the Situation Customer Information System » Customer Information System »CSS-no »CIS-no » Transformer Load Management »yes but not for CIPS »AMR System Load Snapshot »yes but not for CIPS

7. So What Can We do to Determine How Many Electric Heating Customers Ameren has???

8. Utilize our existing residential load research customersHow?

9. 1. Develop a demographic survey for RES load research sample 2. Identify RES LR sample customers by heating type 3. Determine winter/summer energy ratios for RES sample 4. Expand to RES population Our Approach Using Load Research Data

10. Demographic Survey

11. Entry Card Completing the survey made each family eligible for a drawing to receive a check for the amount of their highest electric bill during Summer 2001

12. Responses About 50% of the load research customers returned a completed response

13. Utilizing the Demographic Survey » Separated each customer by electric and non-electric heating and further by their type (baseboard, resistance, or heat pump) » Using LodeStar calculated winter/summer ratios for each customer »Winter (December, January, and February) »Summer (June, July, and August) »Using LodeStar’s Load Analysis Subsystem (LAS) each category was ran as a 100% sample to calculate each customers winter and summer kilowatt-hour

14. Results from Survey » winter/summer ratio > 1.32 = Electric Heating Customer »winter/summer ratio <= 1.32 = Non-Electric Heating Customer The results from the survey were used to calculate a winter/summer breakpoint, the significance was tested using a Z-statistic at the 90% confidence level

15. Sanity Check CIPS 1996 Demographic and Appliance Survey » CIPS 1996 Demographic and Appliance Survey » In 1996, 20% of CIPS residential population were electric and 80% were non- electric heating Results from using 1.32 as the breakpoint » Results from using 1.32 as the breakpoint » 23% of CIPS 2001 residential population are electric heating customers and 77% are non-electric heating customers »this check shows that after 4 years there has been accordingly a slight growth in CIPS residential electric heating customers

16. Breakpoints for the Different Electric Heating Technologies An attempt to find the breakpoints among the different electric heating technologies was inconclusive

19. Conclusion By effectively utilizing Load Research data a count of residential electric heating customers was successfully obtained. A more valid sample size is appropriate to further breakdown by the different types of electric heat.

20. Questions???