2026 Common Case Pre-Release Notes1
2026 Common Case Element / What is Included in Version 0.1 / Summary of Changes from 2024 Common Case / Work to be Completed for Version 1.0- Loads
1.1.Load Year / From actual 2009 / Updated from 2005, Using CEC data for California areas, including DG and PV / None
1.2.Area-Level Loads / Same Areas as 2024 CC / Same Areas as 2024 CC / Update Alberta data to reflect new oil prices.
1.3.Pumping Loads / From actual 2009 / Updated from 2005 / None
1.4.DR, EE, DSM / 2024 DG units / None / Update 2009 NREL data. Update based on LBNL tool. Update EE data based on new load shapes.
1.5.Load Factors / Checked to see if viable / Viable load factors in all TEPPC forecasts / None
1.6.Non-Conforming Loads / Not modeled / Same / None
1.7.Station Service Load / Zeroed out / Same / None
1.8.Seasonal Bus Distribution / Seasonal bus distribution included for HS, HSP,HW, / Updated from 2024 / None
- Resources
2.1.Use of 2025 HS Power Flow Case / Imported into PCM by NTTG / Updated 2023 to 2025 / None
2.2.Use of 2024 Common Case / Basis for resource portfolio / None
2.3.Use of NTTG 2026CC Power Flow / Added CCTA topology, re-imported / Addition of 2026 CCTA topology / None
2.4.Wind and Solar Shapes / 2005 shapes (2024CC) / None / Update to 2009 shapes
2.5.Wind and Solar Capacity Factors / Based on 2005 shapes (2024CC) / None / Update based on 2009 shapes
2.6.Distributed Generation / Updated Per CEC/E3 recommendations via DWG / Capacity Changes / Update 2009 NREL data. Update load bus distribution
2.7.Hydro Year / 2009 / Updated where data is available from 2005 / Update Columbia hydro system for combined 2008 and 2009. Get data for BC Hydro.
2.8.Hydro Profiles / 2009 / Updated where data is available from 2005 / Update Columbia hydro system for combined 2008 and 2009. Get data for BC Hydro.
2.9.Pumped Storage Facilities / Same as 2024 / None / None
2.10.Thermal Facilities / Heat rates pending / No changes from 2024 / Validate
2.11.Plant Retirements / Based on draft list / A few more retirements / Determine how to incorporate Canadian retirements
2.12.Plant Additions / Similar to 2024 / Some removed / Reconcile resource additions
2.13.RPS Compliance Check / Pending / New targets & loads / Implement when complete (currently in progress)
2.14.RA Compliance Check / Pending / New tool / Run RECAP to calculate RA gap and add/remove resources from CC
2.15.FRM Compliance Check / 2024 flex shapes / None / Contract work by ABB to recalculate flex shapes
2.16.Reserve Modeling / FERC 789 implemented / New requirements / Needs to be validated
- Transmission
3.1.Trading Hubs / 2024 / None / None
3.2.Hurdle Rates / Updates from CISO and IID / None / None
3.3.CCTA / 2026 CCTA, topology added to powerflow model / Updated CCTA topology / None
3.4.Modeling Branch Ratings / Same as 2024 CC / None / None
3.5.Nomograms / Same as 2024 CC / None / Remove Southern California “Min Gen” Nomograms except LDWP, apply new CAISO nomogram
3.6.Monitored Lines / Same as 2024 CC / None / None
3.7.Phase Shifters / Same as 2024 / None / None
- Other Data
4.1.Fuels Pricing / NG price pending / Updated / Implement upon decision on NG
4.2.Emission Rates / 2024 / None / None
4.3.Inflation and Discount Rates / Moody’s / New series / Need to be validated
4.4.Reference Year for Pricing / 2016 / Change 2014 to 2016 / None
Western Electricity Coordinating Council