Add input for ElectricStorage SOC timeseries

[adfarth]

Added

• Add ElectricStorage inputs field fixed_soc_series_fraction and fixed_soc_series_fraction_tolerance to allow users to fix the SOC timeseries within a chosen absolute tolerance

Changed

• ElectricStorage state_of_health to state_of_health_series_fraction

Cherry-picked from branch h2-tldrd-mpc by @lixiangk1 with a few small mods

[lixiangk1]

I reviewed the changes and ran some tests and everything seems to make sense. I was wondering if you've noticed in your runs that the cases with the fixed SOC dispatch returns a slightly lower LCC compared to the fixed sizes but unconstrained dispatch? We'd expect it to be slightly higher if results are different right? Is that just a mathematical tolerance thing?

[adfarth]

I reviewed the changes and ran some tests and everything seems to make sense. I was wondering if you've noticed in your runs that the cases with the fixed SOC dispatch returns a slightly lower LCC compared to the fixed sizes but unconstrained dispatch? We'd expect it to be slightly higher if results are different right? Is that just a mathematical tolerance thing?

@lixiangk1 I've found that if I have a run1 with fixed PV and BESS sizes, then do a run2 where the SOC is fixed to run1 SOC with a 1-5% tolerance (and all else held equal):

• the LCC is lower in run2 than run1 due to lower electricity costs (the % diff is a fraction of a %)
• I think this is because the min_soc gets ignored in the second case, so the model can go below the default 20% min as long as it's in the tolerance range.
• So, I think this is okay and makes sense

[adfarth]

changing for consistency in how we index storage

[Copilot]

Pull request overview

Adds support for fixing ElectricStorage state-of-charge (SOC) as a time series (with tolerance), and updates degradation-related naming for battery results.

Changes:

• Add fixed_soc_series_fraction and fixed_soc_series_fraction_tolerance inputs for ElectricStorage, plus corresponding dispatch constraints to enforce a fixed SOC trajectory within tolerance.
• Rename ElectricStorage degradation output state_of_health to state_of_health_series_fraction.
• Add a new scenario + test coverage for fixed SOC behavior.

Reviewed changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
test/scenarios/fixed_pv_bess.json	Adds a simple PV+BESS scenario used by the new fixed-SOC test.
test/runtests.jl	Adds a HiGHS testset validating fixed SOC behavior.
src/constraints/storage_constraints.jl	Implements fixed SOC constraints (and refactors a power-capacity constraint).
src/core/energy_storage/electric_storage.jl	Adds ElectricStorage inputs for fixed SOC series and tolerance; adjusts SOC-related defaults when fixed series is provided.
src/core/utils.jl	Extends JSON/Dict key conversion list to include fixed_soc_series_fraction (and degradation segment arrays).
src/results/electric_storage.jl	Renames degradation output key to state_of_health_series_fraction.
src/results/thermal_storage.jl	Clarifies docstrings to describe outputs as “average year.”
src/results/electric_utility.jl	Fixes formatting/indentation around storage-dependent results.
src/mpc/structs.jl	Adds fixed SOC series/tolerance fields to MPC electric storage structs.
src/mpc/model.jl	Minor variable naming fix in a storage loop.
src/core/reopt.jl	Minor loop variable rename and updates a degradation-related log message.
src/core/electric_tariff.jl	Docstring tweak (adds unit detail for wholesale export rate).
src/core/scenario.jl	Minor docstring list adjustment in Scenario docs.
CHANGELOG.md	Records the new inputs and the degradation output rename.

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[Copilot]

The fixed-SOC constraints only apply for ts in p.time_steps and do not constrain dvStoredEnergy[b, 0]. In MPC (and any case where soc_init_fraction isn’t auto-aligned to the fixed series), this can allow an inconsistent initial SOC or force a large first-step correction that may make the problem infeasible. Consider also constraining dvStoredEnergy[b, 0] to match the first fixed SOC value (within tolerance), or aligning soc_init_fraction automatically whenever a fixed series is provided.

[adfarth]

soc_init_fraction is set equal to fixed_soc_series_fraction[1] in electric_storage.jl. @lixiangk1 does this approach work for MPC?