1. RARF QnA Session November 1, 2007

2. General Information EDS 4-1 RARF due on Friday, November 9, 2007. This includes pink, blue, white cells. (Also should include EDS 3 data) EDS 4-2 RARF due later this year. This includes gray cells.

3. Reference Information Guide and white papers available at http://nodal.ercot.com/readiness/rq/docum ents/index.html http://nodal.ercot.com/readiness/rq/docum ents/index.html http://nodal.ercot.com/readiness/rq/docum ents/index.html Optional help sessions available 9-12 M-F through November 9. Send email to nodalmarkettransition@ercot.com to request a time. nodalmarkettransition@ercot.com

4. Resource Parameter Questions –How do we fill this out for wind resources? N/A for now; how RUC works with wind resources is still a question. –How do we fill this out for combined cycle resources, as breaker close is before we reach LSL and before the steamer is on? –What if there are multiple breakers? –Are these times additive or overlapping? –If I enter zero as minimum online time, will I get startup costs if I am pulled offline before I close the breaker? Enter a 1 to ensure you run. –All time is in hours.

5. Resource Parameter Questions –How do I fill this out? Sample in the guide –Does every point have to be filled in? No. The systems will extend the rates of the first MW back to zero and the last MW to infinity. All numbers are positive. –What if my normal and emergency ramp rates are the same? That is ok. Please enter same information in both sections –How does the Reasonability Ramp Rate fit in? It is used for data validation.

6. Seasonal Net Max Ratings What are the seasonal sustainable and emergency ratings? –PMAX. Net = Generation less auxiliary. The ones in pink is used in Nodal systems while the rest are planning numbers How are these used by Nodal systems?

7. Reactive Capability Questions Where do I get this curve? –Generator manual, known as the D-curve. We will put an example in the guide. What is the Net Maximum Leading/Lagging Operating Capability? –Need to determine if this is still required.

8. Transformer Questions What if there is one transformer for multiple units? –Enter data once What if there are multiple transformers for one unit? –Attach additional information Where would I find the transformer information? –Nameplate, manual, test records

9. Planning Questions Auxiliary load –Define large and small motor –Accuracy of this data –Where do we define the total MW/MVAR of Aux Load?

10. Planning Questions Subsynchronous Resonance –Please provide additional information on what this is and when it will be used. Does not have to be submitted by end of year, but please include a plan on what/how/when you may obtain the data. ERCOT will include additional information in the guide.