Engineering tool · 02

What does storage pressure really cost?

Wall thickness in a pipeline scales with design pressure — Barlow's formula. Because a water-sealed cavern holds a constant, low pressure, the connecting transmission pipeline can be built lighter, and the compressor disappears entirely. This model puts numbers on that difference. Every figure is indicative and intended for discussion, not for investment decisions.

Your scenario

Storage pressure30 bar

Water-sealed caverns: 30–50 bar. Steel-lined: up to ~200 bar.

Number of caverns4

Caverns are built in multiples on one site.

Volume per cavern200 000 m³

Excavation cost900 SEK/m³

Pipeline length120 km

Pipe diameter (DN)600 mm

Steel grade (SMYS)415 MPa

X42 = 290 · X60 = 415 · X80 = 555

Turnovers per year50

Complete fill–empty cycles; drives the energy cost.

Electricity price600 SEK/MWh

Economic life40 yr

The cavern lasts 100+ years; choose the horizon you calculate on.

Levelised cost

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SEK per kg cycled

Wall thickness

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Barlow, ASME B31.12

Storage capacity

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total working gas

Total capital

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caverns + pipeline

Wall thickness vs storage pressure

Barlow: t = (P · D) / (2 · SMYS · F · E · T), with design factor F = 0.5 for hydrogen service. The marker shows your selected pressure.

Cost breakdown

Steel price assumed 14 000 SEK/tonne of line pipe; welding, coating and installation taken as a factor on material cost plus 2.8 MSEK/km. Compression energy 2.5 kWh/kg where compressors are needed; water pumping 0.3 kWh/kg where they are not.

Compared with a 200-bar steel-lined reference

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