Enforce minimum generation level for biopower plants

[shashwatsharma24]

Summary

This PR applies a minimum generation level for biopower available capacity in ReEDS and extends the minimum generation constraint to apply to all historical years (2010-2025). Currently this constraint applies only to nuclear and nuclear SMR plants when GSw_MingenFixed = 1.

Technical details

Comparing technology-level annual generation values from ReEDS default case against reported Form EIA-930 reveals significant differences for historical years. ReEDS under-generates from biopower plants in the default case.

This is at least partly attributable to a mistmatch in biopower fleet capacity between ReEDS and EIA (Form 860):

To close this gap, we enforce a minimum generation level of 50% for biopower plants for all historical (2010-2025) and modeled (2026-) years. This value is consistent with annual capacity factor values ~55-60% for biopower plants reported by EIA.

Implementation notes

We apply a default minimum generation value of 0.5 for biopower to inputs/plant_characteristics/mingen_fixed.csv.

In c_model.gms, eq_mingen_fixed(i,v,r,h,t) enforces minimum generation for the available capacity of technologies listed in mingen_fixed.csv. To apply this for historical years, we remove the conditional for yeart(t)>=Sw_StartMarkets which has a default value of 2026 (operational constraints apply from this year onward).

Relevant sources or documentation

• Capacity Factors for Utility Scale Generators Primarily Using Non-Fossil Fuels, EIA

Validation, testing, and comparison report(s)

Below are plots comparing generation (TWh) mix for ReEDS default case and differences before and after applying minimum generation values of 0.5 (ReEDS_BioMinGen-p5) and 0.7 (ReEDS_BioMinGen-p7) for biopower plants. For the 0.5 case, annual biopower generation increases between 3-8 TWh for historical years, with slight increase in nuclear generation starting 2020 onwards. This mostly replaces coal and gas-CC generation from the mix.

Checklist for author

Details to double-check

• Charge code provided to reviewers
• Included comparison reports for appropriate test cases
• Documentation updated if necessary
• If input data added/modified:
  • Dollar year recorded and converted to 2004$ for GAMS
  • Units are specified
• Code formatting standardized

General information to guide review

• Zero impact on results of default case
• No large data file(s) added/modified
• No substantive impact on runtime for full-US reference case
• No substantive impact on folder size for full-US reference case
• No change to process flow (runreeds.py, reeds/core/solve/solve.py)
• No change to code organization
• No change to package requirements (environment.yml or Project.toml)

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Tag points of contact here if you would like additional review of the relevant parts of the model