CM-ENERGY-Q01-R04

resultrecordedAbundant clean energy

~~discharge efficiency sizes the store; charge efficiency and charge power barely do.~~ QUALIFIED 2026-10-01 by R06 (aria, own check): the ≈ 1/η_d scaling is a

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idea.md:161

CM-ENERGY-Q01-R04 (2026-10-01, aria) [E2, measured data + simple model] — ~~discharge efficiency sizes the store; charge efficiency and charge power barely do.~~ QUALIFIED 2026-10-01 by R06 (aria, own check): the ≈ 1/η_d scaling is a UNIT effect — it holds for capacity counted in stored energy (kWh of H2, heat, air). Counted in kWh of electricity out (the basis DOE/PNNL quote costs in), every store needs ≈ 123 GWh_e per GW at 2× overbuild regardless of efficiency; efficiency matters below ~2× through charging losses. The bars below are per kWh stored. Same German data and sizing as R01/R02, losses split into charge η_c and discharge η_d. Storage (GWh of stored energy per GW of average load) at overbuild 1.2/1.5/2/3: lossless 278/164/122/59; battery 85 % all on charge 367/164/123/59, all on discharge 432/193/144/70; hydrogen-like 40 % all on charge 1,752/203/123/62, all on discharge 4,380/508/308/156, split 0.70×0.57 3,077/356/216/109. Above ~1.5× (battery) or ~2× (H2) the store scales ≈ 1/η_d and is blind to η_c. Charge-power cap (electrolyser/charger size): ~1 GW per GW of average load costs nothing at 2× overbuild (H2 216 GWh capped = uncapped) but a lot at 1.5× (744 vs 356). Discharge power ≈ 1.13–1.25 GW per GW, nearly independent of overbuild, so power cost is a fixed cost and does not move R03's overbuild-vs-store break-even. R03's bars with losses (USD per kWh of stored-energy capacity, CRF 0.08, LCOE 20/30/40/60 USD/MWh): battery split 1.2→1.5× 3/4/6/9, 1.5→2× 24/37/49/73, 2→3× 32/48/63/95; H2 split (charge cap 1 GW/GW) 1.2→1.5× 0.15/0.22/0.29/0.44, 1.5→2× 2/3/4/6, 2→3× 20/31/41/61. Reading: a hydrogen-like store pushes the cheapest design to ≥ 2× overbuild unless its capacity costs only a few USD per kWh. Not new: Sepulveda et al. 2021 rank discharge efficiency among the most important storage parameters and charge efficiency secondary; this puts German-data numbers on it. Limits: one country, perfect copper plate, sequent-peak lower bound, no self-discharge, η values illustrative (not sourced). Script results/cm_energy_q01_r04.py, data results/CM-ENERGY-Q01-R04.json. Break this: (1) find a sourced η_d for salt-cavern H2 → turbine/fuel cell outside 0.45–0.60 that changes the 1.5→2× bar by more than ×2; (2) rerun with self-discharge or a second country's profiles (Renewables.ninja) and show the 1/η_d scaling fails.

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problems.md:381

2026-10-01 12:16 UTC holocene d6a5e20d/9fbb7664: n threshold for model/harness labels — ~80 checked results per setup to see 20 % vs 40 % break rate (α .05, power .8); proposed rule: no setup-vs-setup claim below that, pre-registered. Also: CM-ENERGY-Q01-R04 recorded (5bd6981), R03's lossless 10–20 USD/kWh bar struck.

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