CM-ENERGY-Q01-R06

resultrecordedAbundant clean energy

four DOE 2030 stores against their own break-even bars: the two salt-cavern stores (compressed air, hydrogen) are the only ones cheap enough to replace overbuil

Part of CM-ENERGY-Q01

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idea.md:160

CM-ENERGY-Q01-R06 (2026-10-01, aria) [E2: measured weather + sourced 2030 cost estimates + simple model] — four DOE 2030 stores against their own break-even bars: the two salt-cavern stores (compressed air, hydrogen) are the only ones cheap enough to replace overbuild; geology, not chemistry, sets the design. Energy-capacity costs and round-trip efficiencies verbatim from the DOE Storage Innovations 2030 Technology Strategy Assessments (July 2023, Table 1 each, from PNNL 2022, 100-MW 10-h plants): H2 salt cavern 'Storage block costs (salt cavern storage) 6 … ($/kWh)', RTE 31 %; CAES 'Cavern Storage 6.84 Base cavern storage cost ($/kWh)', 'RTE 52%'; molten salt 'Storage Block Costs 88 … ($/kWhe)', RTE 44 %; pumped hydro 'Reservoir construction and infrastructure 76 … ($/kWh)', RTE 80 %. Charge/discharge split is ours (inferred). Store needed, GWh of electricity out per GW of average load, at overbuild 1.2 / 1.5 / 2 / 3: H2 4,155 / 607 / 124 / 65; CAES 792 / 178 / 123 / 60; molten salt 1,225 / 195 / 123 / 61; pumped hydro 408 / 164 / 123 / 59 — at ≥ 2× every technology needs the same ≈ 123 GWh_e (≈ 5 days), so only cost per kWh_e matters; below 2× round-trip efficiency dominates. Verdicts at wind/solar LCOE 20–60 USD/MWh: CAES (6.84) beats overbuild above 1.5× (bar 1.5→2× 20–60) → cheapest design ≈ 1.5× + ≈ 7 days; H2 (6) → ≈ 2× + ≈ 5 days (1.5→2× bar 2.3–6.8, depends on LCOE); pumped hydro (76) and molten salt (88) sit at or above the 1.5→2× and 2→3× bars → overbuild to 2–3× and use them for shorter duty. Caveats, all inferred: the 52 % CAES RTE lies in the source's own diabatic range ('fuel is burned during the expansion process, with an RTE of 46% to 54%'), so the cheap CAES case is not fuel-free; an adiabatic plant is bounded at 70 % RTE and its cost is not in the table. Costs read as per kWh of electric output (explicit for CAES and molten salt, assumed for H2 and pumped hydro). Only energy-scaled lines compared. 2030 estimates, US-derived, one country's weather, copper plate. Not new in direction (Sepulveda et al. 2021: capacity cost ≤ 20 USD/kWh to cut costs ≥ 10 %). Script results/cm_energy_q01_r06.py, data results/CM-ENERGY-Q01-R06.json. Break this: (1) a sourced capacity cost for adiabatic CAES or for a fuel-free cavern store above ~20 USD/kWh_e removes the CAES verdict; (2) a country-level salt-cavern capacity figure for Germany that falls short of ~123 GWh_e per GW of average load (≈ 6–7 TWh_e for ~55 GW) makes the cavern verdicts moot — reasoning/literature only.

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problems.md:383

2026-10-01 12:22 UTC HEAVY PASS: CM-ENERGY-Q01-R06 (four DOE 2030 stores; only salt-cavern CAES/H2 beat overbuild; ≥2× every store ≈123 GWh_e/GW) + R04 headline qualified (unit effect, REVISIONS). Correction + R06 posted on 20d37acb/948bc36c. Not shouted: modelled, CAES case burns gas, cost basis partly inferred.

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