Joint Meeting Data Work Group – Modeling Work Group

1. Joint MeetingData Work Group – Modeling Work Group Net Qualifying Capacity (NQC) September 10, 2013

2. Status report on NQC related discussions and what to use for generator Pmax? • Jamie Austin

3. What to use for Generator Pmax? • Potential use of Net Qualifying Capacity (NQC) in TEPPC Modeling • What is NQC? • Who reports it and why? • Where to use NQC? • What does Pmax means in the different databases (e.g., EIA, CEMS, LRS, Powerflow, etc.). • Modeling of non-dispatchable Supply (e.g., QF, co-gen, and renewables - non hourly shapes) • Mapping of Databases_ Pmaxcomparison • Should we explore applying hourly temperature correction instead of just using seasonal de-rates?

4. What does Pmax mean in different DBs? • EIA-860: Reported by operator as expected summer and winter rating • Assuming: Expected summer rating • Link: http://www.eia.gov/electricity/data/eia860/index.html • CEMS: Continues Emission Monitoring System (CEMS) established in the Clean Air act of 1990 for elect gen greater than 50 MW w/smoke stack. • Reports gross hourly generation; Station service needs to be subtracted to produce net generation to grid. • Issues: Some reported data is net • Link to ZIP files: ftp://ftp.epa.gov/dmdnload/emissions/hourly/ • LRS: Reported directly to WECC by area coordinator • PowerFlow:

5. Pmax: Gross generation – Kevin Harris • Use published data, EIA-860, if WECC can make available the LRS data reported to EIA, then use LRS data. Ben Brownlee • Start with name plate as proxy values, using LRS values and what’s reported to EIA • Apply summer and winter de-rates • Use NQC for QFs, Co-gen, biomass, geothermal, etc.

6. Consensus Reached – E3 Recommended: • Generally, NQC values become handy when modeling behind-the–meter generation, where data is scarce - one of the major challenges in modeling these units is determining the appropriate split between on-site use (which is embedded in the load forecast) and exports to the grid (which should be modeled as generation resources).

7. Consensus Reached – (continued) Xiaobo had suggested the following for Pmax: • Use NQC for California geothermal and for QF CHPs (i.e., co-gens); • Outage-related de-rate • Do not advocate using NQC, as we already model outages using EFOR. • Transmission-deliverability-limited de-rate • Strongly suggest not to use NQC, because using NQC would unfairly depress generator output in off-peak time. • Ambient-temperature-related de-rate.Do not to use NQC, preferred to apply system wide consistently, rather than just for California.

8. Other consideration for Pmax(Ron Schellberg) • Pmaxstability limit, the true operating limit; it can be higher than nameplate. Also, • 2) Pmax adjusted for machine losses, slightly lower than stability Pmax. Ultimately, we need to answer what is the objective of the Pmax number? Ron shares my view, using historic data to set Pmax can be a trap. As the ultimate goal is, we’re trying to determine plant capacity that contributes to congestion in PCM modeling.

9. Remaining • Recommendation to TAS • NQC Webinar

10. Final Questions & Comments