retail_rate_calculations.py: KeyError 'res_marg_ann_flow' (single-region?), no retail_rate_components.csv

[ty-fi]

Summary

The retail-rate module crashes with KeyError: 'res_marg_ann_flow' when interpolating between solve years, so retail_rate_components.csv is never produced. This appeared on a single-region (single-BA) ND run and is likely because that run has no interregional reserve-margin flows — but it should be confirmed against a multi-region run before assuming it is single-region-specific.

Traceback (from runs/v20260707_213749_ND_small/gamslog.txt)

retail_rate_calculations.py | 21:50:12 | ERROR | File ".../retail_rate_module/retail_rate_calculations.py", line 2337, in <module>
    main(
retail_rate_calculations.py | 21:50:12 | ERROR | File ".../retail_rate_calculations.py", line 534, in main
    interp_between_solve_years(
retail_rate_calculations.py | 21:50:12 | ERROR | File ".../retail_rate_calculations.py", line 111, in interp_between_solve_years
    df_pivot_solve_years.update(df.pivot(index='t', columns=region_type, values=value_name))
retail_rate_calculations.py | 21:50:12 | ERROR | KeyError: 'res_marg_ann_flow'

Diagnosis

In interp_between_solve_years, df.pivot(..., values='res_marg_ann_flow') fails because that column is absent from the frame. The most likely cause: the ND run is a single balancing area, so there are no interregional reserve-margin (res_marg_ann_flow) records to carry that column. A guard for the empty/absent case (skip or create an empty component) would let the module finish.

Impact — missing output

• outputs/retail_rate_components.csv is not produced.

Everything upstream of retail rates is fine — the model solved all years optimally and core outputs (cap, gen, systemcost, reeds-report) are present.

Code references

• postprocessing/retail_rate_module/retail_rate_calculations.py:111 — the failing df.pivot(..., values='res_marg_ann_flow')
• postprocessing/retail_rate_module/retail_rate_calculations.py:534 — interp_between_solve_years(...) call in main

Suggested next step

Reproduce on a multi-region case. If it only fails single-region, guard interp_between_solve_years (or the caller) so a missing/empty res_marg_ann_flow is handled gracefully rather than raising. Upstream code (postprocessing/retail_rate_module/), so also a candidate to report upstream once the scope is confirmed.

[ty-fi]

Did NOT reproduce on a multi-region run — this is single-region-specific

Ran v20260708_143931_Pacific (cendiv/Pacific, aggreg, 11 BAs — multi-region). The retail-rate module completed cleanly: retail_rate_calculations.py logged Finished retail_rate_calculations.py (gamslog.txt:7857) and produced outputs/retail/retail_rate_components.csv. No KeyError: 'res_marg_ann_flow'.

So the crash is specific to single-region (single-BA) runs like ND_Small: with only one balancing area there are no interregional reserve-margin flows, so the res_marg_ann_flow column is absent when interp_between_solve_years tries to pivot on it.

Rescoping: lower priority (multi-region runs are unaffected), and the fix is a guard in interp_between_solve_years (retail_rate_calculations.py:111) — skip or emit an empty component when res_marg_ann_flow isn't present rather than raising.