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Wind ELCC Calculation Comparisons and ERCOT’s NERC LTRA Capacity Forecasts GATF Meeting, June 24, 2014. Summer Season Wind ELCC Calculation Comparisons. Wind ELCC Calculation Comparisons. Two peak-hour averaging methods
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Wind ELCC Calculation Comparisons and ERCOT’s NERC LTRA Capacity Forecasts GATF Meeting, June 24, 2014
Wind ELCC Calculation Comparisons • Two peak-hour averaging methods • “Annual Top 20 Peak Hours” approach (NPRR 611): For top 20 peak hours for a given year, divide the sum of all unit HSLs by the sum of the installed capacities. • “Summer Daily Peak Hours” approach: Sum the HSLs for summer peak season days for hours ending 15:00-18:00, where the summer peak season = June 1 through September 30; divide the sum of the HSLs by the sum of the installed capacities. • Multi-year averaging: • Computed average annual wind ELCC for several time periods: • Two years, 2012-2013 • Three years, 2011-2013 • Four years, 2010-2013 • Five years, 2009-2013 • ERCOT-wide vs. regional breakdown, Coastal and Non-coastal. Note: All calculations use units that are commercially operating as of January 1 of the given year.
Annual ELCC Variability for the Two Peak-hour Averaging Methods, Summer Non-coastal Summer Daily Peak Hour Method Annual Top 20 Peak Hour Method
Annual ELCC Variability for the Two Peak-hour Averaging Methods, Summer Coastal Summer Daily Peak Hour Method Annual Top 20 Peak Hour Method
Annual ELCC Variability for the Two Peak-hour Averaging Methods
Wind ELCC Computation Comparison • Table below compares (1) the two methods of selecting peak hours, (2) different averaging periods, and (3) regional disaggregation vs. ERCOT wide:
Capacity Forecasts for the 2014 NERC Long Term Reliability Assessment
LTRA Resource Categories • Existing-Certain • “Where energy-only markets exist, unit must be a designated market resource eligible to bid into the market” • Planned, Tier 1 • “Resource construction is underway or complete (not in commercial operation)”, or • “Resource has been designated or approved by a market operator and an Interconnection Service Agreement has been signed” • Planned, Tier 2 • ...“Generation Interconnection has been requested”, and apply a confidence factor up to 50% • Planned, Tier 3 • “Capacity that does not meet the requirements of Tier 2”, and apply a confidence factor up to 10%
How ERCOT Addresses Each Resource Category • Existing-Certain • Includes CDR (1) operational resources, (2) hydro capacity contribution, (3) PUN capacity contribution, (4) available switchable capacity, (5) summer/winter available mothball capacity • DC tie capacity contribution treated as imports • Unavailable mothball capacity is categorized as “Existing-Other”, and contributes to NERC’s Prospective Planning Reserve Margin • Planned, Tier 1 • All CDR-eligible new resource capacity • Planned, Tier 2 • Derived and applied (1) annual commercial operation success rates to capacity in the interconnection request queue that is not CDR-eligible, and (2) assumptions concerning timing of those capacity additions through 2024; approach summarized in the next few slides. • Planned, Tier 3 • Derived and applied a 5% annual commercial operation success rate to ERCOT’s list of “conceptual” projects
Project Commercial Operations Success Rates • Data pulled from ERCOT’s GINR database on May 14, 2014
Operations Success Rates by Interconnection Study Phase • Derived annual operations success rates reflecting each project’s status in the interconnection study queue • Interpretation: • 19% of projects with a signed IA will enter commercial operations in any given year during the 10-year LTRA assessment period • 13% of projects in the FIS phase will enter commercial operations in any given year during the 10-year LTRA assessment period • 5% of projects in the SS phase will enter commercial operations in any given year during the 10-year LTRA assessment period
Planned Tier 2 Capacity Derivation • Applied study phase retention rates to applicable project capacity for years 2015-2018 (no projects have CODs beyond 2018). This new capacity totals 2,681 MW by 2018. • Assumed that 19% of all non-CDR-eligible capacity in the interconnection request queue was eventually placed in service by 2024; this amount is 4,905 MW. • Deducting capacity additions for years 2015-2018 leaves 2,224 MW to allocate to years 2019 through 2024; assumed that this amount was distributed equally (371 MW for each year). • Reasonableness check: LTRA Planned Tier 1 and 2 capacity more than keeps pace with the CDR load increase from 2015 through 2024 • Need 9,254 MW by 2024 to keep pace with the CDR forecasted load increase plus make up for DT Deely plant loss in 2019. • LTRA Planned Tier 1 plus Tier 2 totals 10,555 MW.
Planned Tier 2 Capacity Derivation • Table below shows year by year derivation of the Planned Tier 2 confidence factors and resulting capacity amounts
LTRA Capacity Summary • The table below is an extract of the LTRA data form showing the resource capacity section; the data is considered “draft”. • Final data is due June 27, 2014.