[v3.11.11] SAM-EM MCY Levelized Metrics Update

[softwareengineerprogrammer]

Description

1. Addresses SAM-EM Multiple Construction Years: SAM SME Design Review NatLabRockies/GEOPHIRES-X#444 (comment)
2. Adds full cash flow CSV link to SAM-EM MCY documentation per SAM-EM Multiple Construction Years: SAM SME Design Review NatLabRockies/GEOPHIRES-X#444 (comment)

SME Review

Questions

1. Why does SAM report LCOE in Year 0 instead of Year -1? Should GEOPHIRES follow the same convention (even for long construction periods where Year -N vs. Year 0 LCOE is significantly different)?
   1. A: Basis for question was incorrect, SAM does not have Year -1
2. What other rows (if any) should be considered for backfilling? (e.g. pre/after-tax returns)
   1. A: Heuristic: backfill rows directly related to levelized metrics.
   2. Implementation decision: Backfilling AFTER-TAX LCOE AND PPA PRICE rows; not backfilling pre-/post-tax return rows

Demonstrations of backfill calculations

Generated at d69798b:

1. https://gist.github.com/softwareengineerprogrammer/64bffe886046ccf70b2871369dcb14e9#file-sam-em-mcy-levelized-metrics_2026-01-26-2_separate-backfilled-rows-csv-L112:

2. https://gist.github.com/softwareengineerprogrammer/6e54cdf9cc9456790b01695027353855#file-sam-em-mcy-levelized-metrics_2026-01-26-2_native-backfilled-rows-csv-L112

TODO

1. CHANGELOG entry
2. 🚧 Sync web interface examples/schema
3. Regenerate FPC5 sensitivity analysis once web interface backend has been updated (otherwise shared result LCOEs will be out of sync/incorrect): https://github.com/softwareengineerprogrammer/GEOPHIRES/pull/132/commits/fbe041cdca79aedd939003780475b85dae9c6fa7a
4. Update LCOE tooltip text (if necessary/applicable - pending review of current content): Not necessary for now, "For SAM economic models, this is the nominal LCOE value (as opposed to real)." remains accurate. Created tangentially-relevant tracking issue: SAM-EM LCOE/Electricity breakeven price field name discrepancy NatLabRockies/GEOPHIRES-X#459
5. Add sanity-check-level unit tests: a99b942
6. Sync SAM-EM MCY documentation: 7956432, 1648289, 3e68325
7. Update examples: 4431a0d
8. LPPA: 43bc438
9. Update LCOE extraction logic: 1ce5e73
10. Backfill pre/after-tax returns (?) (See Questions section above)

Testing & Verification

1. Unit tests added: test_post_processed_levelized_metrics
2. Unit tests updated: Regenerated affected examples (https://github.com/softwareengineerprogrammer/GEOPHIRES/pull/132/changes#diff-afd6405a1fe39334a3befccfb8e1c2a6de10076dcef2731c48a7f0cf11aca3ac). Note that example LCOE/metrics are unaffected and some cash flows are only negligibly different due to trivial differences in rounding conventions for backfilled line items (per relevant commit messages).
3. Manual testing: Manually tested locally and with web interface

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Change Checklist:

Observe the following checklist items if your change includes a new version (see versioning notes and version management docs).

Before merging:

1. Add a CHANGELOG entry (example). RST Template:

M.m.P: `TITLE <https://github.com/NREL/GEOPHIRES-X/pull/PR-NUMBER>`__ | `release <https://github.com/NREL/GEOPHIRES-X/releases/tag/vM.m.P>`__

After merging:

1. Push tag(s) to GitHub: git push origin refs/tags/vM.m.P
2. Post a change announcement to the GEOPHIRES Change Announcements Discussion (example). Markdown template:

M.m.p: [TITLE](https://github.com/NREL/GEOPHIRES-X/pull/PR-NUMBER) | [release](https://github.com/NREL/GEOPHIRES-X/releases/tag/vM.m.P)

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Additional metadata such as TODO items or link to your initial self-review (PR into your own fork created prior to submission)