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Joint Meeting Data Work Group – Modeling Work Group. Net Qualifying Capacity (NQC) September 3, 2013. Overview. What should be used for generator Pmax in the TEPPC databases? Should we use generator nameplate, Powerflow Pmax , CEMS or EIA data for Pmax in the PCM databases?
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Joint MeetingData Work Group – Modeling Work Group Net Qualifying Capacity (NQC) September 3, 2013
Overview • What should be used for generator Pmax in the TEPPC databases? • Should we use generator nameplate, Powerflow Pmax, CEMS or EIA data for Pmax in the PCM databases? • Where should NQC be used? • Does CAISO already use NQC for Pmax in Powerflow cases?
What is Net Qualifying Capacity? • Jamie Austin
Net Qualifying Capacity (NQC“California Exclusive” substitute for Pmax • NQC is the amount of capacity that can be counted from each resource toward meeting Resource Adequacy (RA). • NQC is established by the CAISO and represents the MINIMUM of: • Deliverability - the ability of the output of a generating resource to be delivered to aggregate load . • QC - the only difference between QC and NQC is the deliverability of the resource to aggregate California ISO load. • Outage Derates- scheduled outages greater than 25% of days in a month reduce the amount of NQC: “Planned” with a duration greater than seven days and “Forced” of any duration. • Availability Test - resource’s most recent maximum power plant output (PMax) based on testing by California ISO (not required to intermittent resources)
Net Qualifying Capacity • NQC is calculated as an average rating on hot afternoon summer day at which time wind and hydro will not hold full capacity. • Ambient temperatures and altitudes derates are reflected in Summer\Winter ratings. • Delivery restriction such as transmission (e.g., restrictions do to single pole switching- SPS, N-1 and N-2, mainly N-2); if used in production cost modeling these could result in “double-dipping” as such factors are also reflected in transmission ratings.
CAISO – 2012 Annual Report on Market Issues & Performance Study
CAISO – 2012 Annual Report on Market Issues & Performance Study
CAISO – 2012 Annual Report on Market Issues & Performance Study
NQC application • NQC values are intended for scarcity analysis and resource adequacy. • Resource adequacy – to determine incremental resources to fill the gap • Reserves determination, part of the planning margin calculation • Not applicable in Production Cost Modeling. • Howerver, there are exceptions to the rule; NQC values become handy when modeling behind-the-meter generation, where data is scarce. As E3 summarizes, “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 a generation resource)”.
What Does Pmax means in the different databases (e.g., EIA, LRS, Powerflow)? • Kevin Harris
Defining Max Rating • What does Pmax means in different DB: • 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:
Modeling of non-dispatchalbe Supply (e.g., QF, co-gen, and renewables – non hourly shapes) • Kevin Harris
Modeling of Non-Dispatchable Supply • WECC TEPPC data set for 2022 contains 25,802 MW of Non-Dispatchable supply with a dispatch range of 13,300 MW • Recommended modeling of non-dispatchable supply: • Allow no dispatchable range (Min Cap = Max Cap) • Model as flat monthly shape • Order of selecting monthly shape (max rating) • Use NQC monthly shapes for QF & CG • Use multi year historic avg monthly gen (aMW) • Shape aMW by month, On-Peak & Off-Peak • No EFOR or SOF (implied in above aMW) From TEPPC 2022 Data Set
Dispatchable CG • When its determined that a plant is dispatchable with a min generation requirement model the pieces to represent the net operation of the plant • For example modeling of SCA CG II (2x1 CCGT)
ISO Condition for Turbines • (ISO)International Organization for Standardization • The standard used for gas turbine is ISO 3977: • Ambient Temp: 59.0˚F (15.0˚C) • Elevation: Sea level (14.696 psia) • Relative Humidity: 60% • Heat Rates are reported in: • LHV (Lower Heating Value): Heat rate without any degradation do to fuel burned • HHV (Higher Heating Value): Adjusted heat rate to account for any degradation do to the fuel burned • For NG: HHV:= LHV * 1.1111
Converting manufacture data to summer HR Chart for Siemens:
Mapping of Databases_Pmax Compare • Ben Brownlee
NQC Use in Powerflow Cases • Following is a summary response to Ben’s survey of California Area Coordinators concerning the NQC use in the powerflow cases. • Southern California: “Annual NQC” (derived somehow from the monthly NQC values) is used as the PMAX of all existing generators. Generator owner’s reported physical capability is used as the PMAX for planned/future units. • Northern California: NQC is used as the PGEN (dispatch) of generators. Generator owner’s reported physical capability is used for the PMAX of existing and planned/future units.
Should we explore applying hour temperature corrections instead of just using seasonal de-rates? • Xiaobo Wang
Xiaobo’s Recommendation • Actual output capability of California geothermal units important to use NQC values (or concept) to apply de-rate multipliers to maximum capacity. • Normal output of California QF CHPs (i.e. co-gens)necessaryto use NQCvalues (or concept) to apply de-rate multipliers to maximum capacity. • 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.I suggest not to use NQC, because I would rather do it system wide consistently, rather than just do it for California.
Ambient temperature de-rate on generatorsA proposed modeling approach • In each area, select some representative locations and maintain a library of temperature profiles for the database characteristics year (e.g. 2005). The temperature data shall be easy to get from public domain. • Let each thermal generator carries an algebraic equation:d(t) = at2 + bt + cwhere:t is ambient temperatured is de-rate multipliera, band care coefficients provided by the modeler • Use dto scale each generator’s heat-rate blocks, not just the maximum capacity
Ambient temperature de-rate on generatorsPros and cons Pros: • Generic functionality using generic data (or specific data) • Once the model is built, no need to keep on chasing data • 8,760 hourly de-rate is better than seasonal de-rate • Locations are better reflected • Merely input data processing, no penalty on run time • The temperature library can also be used for other purposes, e.g. temperature-affected transmission limits* Cons: • The existing S/W needs to be enhanced to model this * In the production simulation model, the CAISO is already using a temperature-affected transmission limit. One application is on modeling the dynamic rating of Path 15 based on the CAISO’s operating procedure
Ambient temperature de-rate on generatorsRecommendations To do: • Need some more research to establish ‘typical’ parameters to be used as default coefficientsExample: d(t) = 1 - b(t – t0) • It is possible that the coefficients vary slightly(?) for different types of generators (CT, CC, ST, etc.) Recommendations: • No hurry to implement this temperature model • Focus on fundamentals of building the new 2024 dataset • This model can be implemented after the 2024 dataset is released, as an add-on in a later DB revision Quoted from a literature: “Each 1oC increase in ambient air temperature, the power output will decrease by 0.74%”