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Energy mass balanceCostingHydrogen

Hydrogen diaphragm compressor for 350/700 bar refuelling

One diaphragm compressor at a 350 or 700 bar station (20-200 bar suction, 450-950 bar discharge): stage count under a per-stage ratio limit, real-gas isentropic work with the NIST compressibility equation, specific energy and absorbed power, heat to the coolers, N+1 availability, installed CAPEX from NREL 2014 vendor quotes on a 0.66 law or a customized figure, and the levelized cost of compression in EUR/kg.

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Open Jack

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  • CurrencyEUR 2013
  • Battery limitinstalled
  • 101 documented assumptions
  • Updated2 Nov 2026

Mass and energy balance

What the asset draws and delivers for the case and load you choose.

Reference case

Share of the year at design throughput. Default 80 %, the mature-station value of DOE Record 18003. Capped by the availability: 85 % with one machine.

Flows

  • In: Hydrogen at suction pressure—
  • In: Electricity—

Asset

Hydrogen diaphragm compressor (350/700 bar station)

  • Out: Compressed hydrogen at discharge pressure—

Annual quantities at the current usage.

Design hydrogen flow of one machine. Chain it on the electrolyser, purifier or tube-trailer output. Default 100 kg/h, the Burckhardt MD10 rating; the Howden TFC90 is 90 kg/h. The cost anchors are 32 and 35 kg/h (NREL 2014), so above about 100 kg/h the 0.66 law is extrapolated.

Absorbed electrical power
— kW
Number of stages
— -
Heat to the coolers
— kW
Installed CAPEX
— EUR

CAPEX

Specific cost at this size, what backs it, and how it behaves with scale.

Specific CAPEX at this size

—

Reference size 32 kg/h

NREL 2014

Model value: the NREL 2014 quote of the pressure class, scaled with the 0.66 exponent. Customized: your own figure, typed below, used as is at every size. A customized CAPEX is no longer sourced by this calculator.

Specific CAPEX by hydrogen throughput

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  1. Ex-factory
  2. Installed· this figure
  3. Fully financed
CAPEX at the battery limit—
Working capital, contingencyproject level

Included

  • Equipment
  • Installation, civil works and engineering

Not included

  • Working capital
  • Contingency

Added at project level

  • Working capital layer, from the project settings
  • Contingency, from the project settings

Project figures

Values passed to project mode when this asset is added to a project.

Concept sketch, not to scale · drag to rotate

Hydrogen at suction pressure in
—
Electricity in
—
Compressed hydrogen at discharge pressure outMain product
—
CAPEX to the battery limit
—
Fixed O&M
—
Variable O&M, excluding feedstocks
0 EUR/year
Asset lifetime
10 years

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Levelized cost of compression

A standalone indicator for a quick read. Project mode recomputes it for the whole system.

—

  • Capital share—
  • O&M share—
  • Electricity share—

Linked to the balance above

Share of the year at design throughput. Default 80 %, the mature-station value of DOE Record 18003. Capped by the availability: 85 % with one machine.

Pressure at the compressor inlet: about 20 bar from a pressurised electrolyser (the DOE Record 9013 basis), up to 200 bar from a tube trailer or medium-pressure storage.

450 bar for 350 bar fills, 950 bar for 700 bar fills. Up to 550 bar the CAPEX uses the 500 bar quote, above it the 875 bar hybrid quote; above 875 bar the cost is extrapolated, as no source prices an all-diaphragm 950 bar machine.

Largest ratio accepted on one diaphragm head. Default 6, derived from the NREL Vendor A machine (20 to 120 bar first stage). 10 is the PPI/Sundyne printed maximum. Below 4, 20 to 950 bar would need a fourth stage, outside the machine class.

Diaphragm machines need heavy maintenance. N+1 buys a second identical machine: CAPEX and O&M double, availability rises from 85 % to 97.75 %.

Default 0.18 EUR/kWh, the EU average non-household price of H1 2026 (Eurostat, 500-2,000 MWh band, excl. VAT). It is used as typed, while the CAPEX stays in EUR 2013.

Yearly maintenance, diaphragms and valves included. Default 4 %, the DOE target for small compressors, optimistic for a diaphragm machine: NREL 2014 shows maintenance from 0.11 to 0.71 USD/kg depending on the time between failures.

Default 7 %, the station discount rate of DOE Record 18003, read as real since costs are constant euros.

Default 10 years, the station analysis period of DOE Record 18003. No source for the physical service life of a diaphragm compressor was established.

Levelized cost of compression by utilization

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Benchmarks

This model's figures against published references and reference cases.

Specific energy, kWh/kg

1.47 DOE Record 9013

1.7 DOE Record 9013

3 DOE Record 9013

6.4 DOE Record 9013

8.3 NREL 2014

Reference cases at this size and usage

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All results

Every model output at the current settings, grouped, with the sensitivity charts.

49 outputs · 6 groups · 13 also shown above, dimmed

Cost of compression

10
Levelized cost of compression
ComputingEUR/kg
Capital share
ComputingEUR/kg
O&M share
ComputingEUR/kg
Electricity share
ComputingEUR/kg
Electricity in the levelized cost
Computing%
Capital recovery factor
Computing1/year
Annualised CAPEX
ComputingEUR/year
O&M per year
ComputingEUR/year
Electricity cost per year
ComputingEUR/year
Total annual cost
ComputingEUR/year

Staging

7
Number of stages
Computing-
Pressure ratio per stage
Computing-
Overall pressure ratio
Computing-
First stage discharge
Computingbar
Second stage discharge
Computingbar
Third stage discharge
Computingbar
Stage discharge temperature
ComputingdegC

Real gas and energy

12
Specific energy
ComputingkWh/kg
Compressibility at suction
Computing-
Compressibility at discharge
Computing-
Real-gas penalty factor
Computing-
Isentropic work
ComputingkWh/kg
Isentropic work, ideal gas
ComputingkWh/kg
Shaft work
ComputingkWh/kg
Isentropic efficiency
Computing%
Isothermal work, ideal gas
ComputingkWh/kg
Isothermal efficiency
Computing%
Compression energy in LHV terms
Computing%
NIST Z equation check
Computing-

Power and heat

6
Absorbed electrical power
ComputingkW
Shaft power
ComputingkW
Heat to the coolers
ComputingkW
Motor losses
ComputingkW
Electricity per year
ComputingMWh/year
Heat and losses per year
ComputingMWh/year

Operation

4
Availability
Computing%
Delivered utilization
Computing%
Full-load hours
Computingh/year
Hydrogen compressed per year
Computingt/year

CAPEX

10
Installed CAPEX
ComputingEUR
Specific CAPEX
ComputingEUR/(kg/h)
Specific CAPEX, model value
ComputingEUR/(kg/h)
Specific uninstalled cost, USD 2013
ComputingUSD/(kg/h)
Uninstalled cost, USD 2013
ComputingUSD
CAPEX per kW absorbed
ComputingEUR/kW
CAPEX anchor pressure
Computingbar
Discharge above the CAPEX anchor
Computingbar
Throughput over the CAPEX anchor
Computing-
Machines installed
Computing-

Sensitivities

6 charts
Cost of compression components vs utilization

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Cost of compression by reference case (1 NREL diaphragm 80 %, 2 DOE base 65 %, 3 NREL pessimistic 50 %)

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Specific energy and stage count vs suction pressure

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Compressibility and real-gas penalty vs discharge pressure

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Cost of compression and specific CAPEX vs throughput

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Cost of compression vs electricity price

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Sources

101 documented assumptions · 8 sources

About

Calculator context

Sizes and costs one hydrogen diaphragm compressor at a refuelling station, from its suction flange to its discharge flange. Suction runs from 20 bar (a pressurised electrolyser, the DOE Record 9013 basis) to 200 bar (tube trailer or medium-pressure storage); discharge is 450 bar for 350 bar fills or 950 bar for 700 bar fills. Storage, dispensers, pre-cooling and purification stay outside. The throughput input, h2_throughput in kg/h, is the one a catalogue product rates: Burckhardt MD10 (100 kg/h) and Howden TFC90 (90 kg/h).

Physics. The number of equal-ratio stages is the smallest that keeps each stage under the maximum ratio you accept (default 6:1, derived from the NREL Vendor A machine; PPI/Sundyne print up to 10:1). Every stage starts at 300 K after its intercooler. Its isentropic work uses k = 1.41 (derived from NIST WebBook data) and the mean compressibility at its suction and discharge, from the NIST standardized equation for hydrogen (Lemmon, Huber and Leachman 2008), reproduced on its published test point. Z is about 1.28 at 450 bar and 1.61 at 950 bar, so an ideal-gas model would miss a large part of the work: the real-gas penalty factor shows how much. Shaft work follows from the isentropic efficiency of the reference case (80 % NREL diaphragm judgement, 65 % DOE base, 50 % pessimistic), electricity from a 92 % motor. The shaft work goes to the intercoolers and after-cooler, the motor losses to the room.

Operation. One machine is available 85 % of the year (DOE target); N+1 buys a spare, doubling CAPEX and O&M and raising availability to 97.75 %. The hydrogen delivered follows the utilization (default 80 %, DOE Record 18003), capped by availability.

Economics. The uninstalled cost scales the NREL 2014 quote of the pressure class with NREL's 0.66 exponent: 376,000 USD for a 35 kg/h two-stage diaphragm to 500 bar (used up to 550 bar), 514,000 USD for a 32 kg/h hybrid diaphragm plus dry-piston machine to 875 bar (used above). It is converted at NREL's 1.35 USD per EUR and multiplied by NREL's 1.3 installation factor: an installed figure in EUR 2013, with no escalation. O&M is a share of installed CAPEX (default 4 %, the DOE target, optimistic for diaphragms). The levelized cost of compression is annualised CAPEX at a real rate plus O&M over the hydrogen delivered, plus specific energy times the electricity price; it excludes the value of the hydrogen itself.

Extrapolations, flagged in the outputs. No source prices an all-diaphragm 20 to 950 bar machine: above 875 bar the cost is extrapolated. The 0.66 exponent comes from two machines about three times apart and is stretched up to 15 times the anchors. CAPEX follows throughput and pressure class only, not suction pressure or stage count. The 80 % efficiency is expert judgement; Humboldt State measured 8.3 kWh/kg on a small single-stage diaphragm unit, far above the model. The standalone cost mixes 2013 capital with the electricity price you type.

Model

159 variables — inputs, calculations and outputs, with their dependencies.

159 variables shown of 159
VariableValueUnitDepends on
100kg/h—
1——
20bar—
950bar—
6——
0——
80%—
0.18EUR/kWh—
4%—
0——
10500EUR/(kg/h)—
7%—
10years—
VariableFormulaUnitDepends on
if((<=)+(>)+(<=)+(<=)+(<=)+(>)+((!=)*(!=)*(!=))+((!=)*(!=))+((!=)*(!=))+((>=)*((<)+(>)))+(<=)+(>)+(<)+(<)+(<)+(>=)+(<)+((>)*(>)*(ceil(ln(max(/max(,),+))/ln(max(,+)))>))>,,)bool
+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^-
+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^-
/(/)J/(kg.K)
**/(-)*(^((-)/)-)/kWh/kg
(+)**kWh/kg
if(>=,(+)**,)kWh/kg
if(>=,(+)**,)kWh/kg
*kg/year
if(<=,,)USD
if(<=,,)kg/h
*ratio
VariableFormulaUnitDepends on
/max(,)-
max(,ceil(ln(max(,+))/ln(max(,+))))-
^(/)-
min(*,)bar
min(*^,)bar
min(*^,)bar
+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^-
+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^+*(/)^*(()//)^-
(+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^+*(/)^*(/)^)/-
++kWh/kg
*kWh/kg
/max(,)-
if(==,,if(==,,))%
/(*)kWh/kg
/(*)kWh/kg
*(+(^((-)/)-)/(*))-degC
**ln(max(,+))/kWh/kg
/max(,)*%
/*%
*kW
*kW
kW
-kW
if(==,(-(-*)^)*,)%
min(,)%
**h/year
/t/year
**MWh/year
MWh/year
if(<=,,)bar
/*(/)^(-)USD/(kg/h)
/*EUR/(kg/h)
if(>=,,)EUR/(kg/h)
if(==,,)-
**EUR
/*USD
/max(,)EUR/kW
max(,-)bar
/-
if(<,/max(,),(*(+)^)/max((+)^-,))1/year
*EUR/year
**EUR/year
**EUR/year
++EUR/year
/max(,)EUR/kg
/max(,)EUR/kg
/max(,)EUR/kg
++EUR/kg
/max(,)*%

Assumptions

101 assumptions used in the calculations

  • BOUNDARY. One diaphragm compressor package at a 350 or 700 bar refuelling station, from the suction flange (electrolyser outlet, tube trailer or medium-pressure storage, 20 to 200 bar) to the discharge flange (450 bar for 350 bar fills, 950 bar for 700 bar fills). Inside: one to three intercooled diaphragm stages, the after-cooler, the motor and the package installation. Outside: storage, dispensers, pre-cooling, purification and the station building. A diaphragm machine is hermetic, so no hydrogen loss is modelled: the hydrogen leaving equals the hydrogen entering.

    Market range Not applicable.

    —
    Brief perimeter

  • METHOD 1, STAGES. n = ceil(ln(P2/P1) / ln(r_max)), at least 1, and r = (P2/P1)^(1/n) for every stage (equal ratios). r_max is the largest ratio the user accepts on one diaphragm head: default 6 (derived from the NREL Vendor A first stage, 120/20), slider 4 to 10 (10 is the PPI/Sundyne printed maximum). The slider stops at 4 because 20 to 950 bar would then need a fourth stage, which no diaphragm machine in the sources has. The brief suggested 3 to 4 per stage; the sources print more, so the default is 6.

    Market range Vendor A about 6:1 and 4.2:1; PPI up to 10:1.

    —
    Equal-ratio staging rule

  • METHOD 2, REAL GAS. Z(p, T) = 1 + sum over i = 1..9 of a_i (100 K / T)^b_i (p / 1 MPa)^c_i, with the NIST Table 1 coefficients. Z is about 1.28 at 450 bar and 1.61 at 950 bar (300 K): the ideal-gas assumption is not acceptable above about 300 bar. Each stage uses the mean of Z at its suction and its discharge pressure, both at 300 K. This averaging is a modelling choice, not sourced.

    Market range Not applicable.

    —
    NIST equation, averaging choice

  • METHOD 3, WORK. Every stage starts at 300 K (perfect intercooling, the reference temperature of DOE Record 9013). Stage isentropic work w_i = Z_stage x (R/M) x T1 x k/(k-1) x (r^((k-1)/k) - 1), with R = 8.314472 J/mol/K, M = 2.01588 g/mol and k = 1.41. Shaft work = sum of w_i / isentropic efficiency; electricity = shaft work / motor efficiency (92 %). Absorbed power = specific energy x throughput. The real-gas penalty factor is the ratio of the real-gas to the ideal-gas (Z = 1) isentropic work.

    Market range Not applicable.

    —
    Isentropic stage work

  • METHOD 4, HEAT. Heat to reject in the intercoolers and after-cooler = shaft power. Motor losses = absorbed power - shaft power. All the electricity therefore ends as heat (the heat and losses output), at a temperature too low to chain as a product. The stage discharge temperature is T1 x (1 + (r^((k-1)/k) - 1) / isentropic efficiency).

    Market range Not applicable.

    —
    First-law approximation

  • METHOD 5, AVAILABILITY. One machine is available 85 % of the year (DOE target). With N+1 redundancy a second identical machine is bought, and the pair is available 1 - (1 - 0.85)^2 = 97.75 % (independent failures, a modelling choice). The hydrogen delivered follows the utilization you set, capped by that availability: above 85 % utilization a single machine cannot keep up.

    Market range Not applicable.

    —
    DOE target plus independence

  • METHOD 6, CAPEX. Uninstalled cost = C_ref x (throughput / Q_ref)^0.66, USD 2013. Discharge up to 550 bar: C_ref = 376,000 USD for 35 kg/h (two-stage diaphragm, 20 to 500 bar). Above 550 bar: C_ref = 514,000 USD for 32 kg/h (hybrid two-stage diaphragm plus dry-running piston, 875 bar cascade). Then / 1.35 USD per EUR (NREL's rate) and x 1.3 installation (NREL panel), x 2 with N+1. The result is an installed figure in EUR 2013, battery limit installed: project mode adds only its working-capital layer and contingency. A customized specific CAPEX, per kg/h of one machine, replaces the model value at every size.

    Market range Not applicable.

    —
    Vendor quotes, NREL exponent

  • EXTRAPOLATIONS. (a) No quote covers an all-diaphragm 20 to 950 bar machine: above 875 bar the cost is extrapolated (output: discharge above the CAPEX anchor). Catalogue diaphragm products reach about 550 bar (Burckhardt MD10, Howden TFC90). (b) The 0.66 exponent is used from 5 to 500 kg/h, up to 15 times the anchors (output: throughput over the anchor). (c) CAPEX follows throughput and pressure class only: within one class, a one-stage 200 to 450 bar machine costs the same as a three-stage 20 to 450 bar one, which overstates the cost of high-suction duties. (d) The 80 % isentropic efficiency is NREL expert judgement; Humboldt State measured 8.3 kWh/kg on a single-stage diaphragm from 13 to 430 bar.

    Market range Not applicable.

    —
    Published gaps

  • METHOD 7, LEVELISED COST. CRF = i / (1 - (1 + i)^-N), or 1/N at i = 0. Levelised cost of compression = (installed CAPEX x CRF + O&M) / hydrogen delivered per year + specific energy x electricity price. It is a service cost: it excludes the value of the hydrogen compressed (no loss on a diaphragm machine). Costs are constant EUR 2013 with no escalation and the rate is read as real; the electricity price you type is used as is, so the standalone figure mixes 2013 capital with today's power price (HICP indexing not applied, as in the brief).

    Market range Not applicable.

    —
    DOE levelised cost convention

  • CHAINING. Chain the hydrogen inlet on the electrolyser, purifier or trailer output, and the outlet on the high-pressure storage or dispenser. Electricity is an inlet (MW, average over the year), priced by the project; the fixed O&M is the only opex line.

    Market range Not applicable.

    —
    Meta contract

  • Guards divisions and logarithms.

    Market range Not applicable.

    0
    Numerical constant

  • Unit multiplier in the guard, the staging and the CRF.

    Market range Exact.

    1
    Numerical constant

  • Neutral value in the guard and the switches.

    Market range Exact.

    0
    Numerical constant

  • Mean of the Z factor at the suction and discharge of a stage.

    Market range Exact.

    0.5
    Numerical constant

  • Percent to fraction.

    Market range Exact.

    0.01
    Unit conversion

  • Fraction to percent, and the 100 % limit of the guard.

    Market range Exact.

    100%
    Unit conversion

  • Annualises the hydrogen delivered and the electricity.

    Market range 8760 or 8784 h.

    8760h/year
    Time convention

  • kWh to MWh.

    Market range Exact.

    0.001MWh/kWh
    Unit conversion

  • kg to t for the annual hydrogen.

    Market range Exact.

    1000kg/t
    Unit conversion

  • Molar mass in g/mol to kg/mol.

    Market range Exact.

    1000g/kg
    Unit conversion

  • Specific work in J/kg to kWh/kg.

    Market range Exact.

    3600000J/kWh
    Unit conversion

  • Pressure in bar to MPa for the NIST equation.

    Market range Exact.

    10bar/MPa
    Unit conversion

  • Kelvin to degrees Celsius for the discharge temperature.

    Market range Exact.

    273.15K
    Unit conversion

  • Index of the second stage (active when n >= 2).

    Market range Not applicable.

    2
    Index

  • Index of the third stage (active when n = 3).

    Market range Not applicable.

    3
    Index

  • Reference case 1: NREL 2014 diaphragm, 80 % isentropic.

    Market range Not applicable.

    1
    Selector code

  • Reference case 2: DOE base case, 65 % isentropic.

    Market range Not applicable.

    2
    Selector code

  • Reference case 3: NREL pessimistic case, 50 % isentropic.

    Market range Not applicable.

    3
    Selector code

  • Redundancy 0: one duty machine (N).

    Market range Not applicable.

    0
    Selector code

  • Redundancy 1: duty plus spare machine (N+1).

    Market range Not applicable.

    1
    Selector code

  • Machines bought with N.

    Market range Not applicable.

    1
    Count

  • Machines bought with N+1: one duty, one identical spare.

    Market range Not applicable.

    2
    Count

  • Coefficient a_1 of the NIST Z equation.

    Market range Exact as printed.

    0.058885
    NIST Table 1

  • Temperature exponent b_1 of the NIST Z equation.

    Market range Exact as printed.

    1.325
    NIST Table 1

  • Pressure exponent c_1 of the NIST Z equation.

    Market range Exact as printed.

    1
    NIST Table 1

  • Coefficient a_2 of the NIST Z equation.

    Market range Exact as printed.

    -0.061361
    NIST Table 1

  • Temperature exponent b_2 of the NIST Z equation.

    Market range Exact as printed.

    1.87
    NIST Table 1

  • Pressure exponent c_2 of the NIST Z equation.

    Market range Exact as printed.

    1
    NIST Table 1

  • Coefficient a_3 of the NIST Z equation.

    Market range Exact as printed.

    -0.00265
    NIST Table 1

  • Temperature exponent b_3 of the NIST Z equation.

    Market range Exact as printed.

    2.5
    NIST Table 1

  • Pressure exponent c_3 of the NIST Z equation.

    Market range Exact as printed.

    2
    NIST Table 1

  • Coefficient a_4 of the NIST Z equation.

    Market range Exact as printed.

    0.002731
    NIST Table 1

  • Temperature exponent b_4 of the NIST Z equation.

    Market range Exact as printed.

    2.8
    NIST Table 1

  • Pressure exponent c_4 of the NIST Z equation.

    Market range Exact as printed.

    2
    NIST Table 1

  • Coefficient a_5 of the NIST Z equation.

    Market range Exact as printed.

    0.001802
    NIST Table 1

  • Temperature exponent b_5 of the NIST Z equation.

    Market range Exact as printed.

    2.938
    NIST Table 1

  • Pressure exponent c_5 of the NIST Z equation.

    Market range Exact as printed.

    2.42
    NIST Table 1

  • Coefficient a_6 of the NIST Z equation.

    Market range Exact as printed.

    -0.001151
    NIST Table 1

  • Temperature exponent b_6 of the NIST Z equation.

    Market range Exact as printed.

    3.14
    NIST Table 1

  • Pressure exponent c_6 of the NIST Z equation.

    Market range Exact as printed.

    2.63
    NIST Table 1

  • Coefficient a_7 of the NIST Z equation.

    Market range Exact as printed.

    0.000096
    NIST Table 1

  • Temperature exponent b_7 of the NIST Z equation.

    Market range Exact as printed.

    3.37
    NIST Table 1

  • Pressure exponent c_7 of the NIST Z equation.

    Market range Exact as printed.

    3
    NIST Table 1

  • Coefficient a_8 of the NIST Z equation.

    Market range Exact as printed.

    -0
    NIST Table 1

  • Temperature exponent b_8 of the NIST Z equation.

    Market range Exact as printed.

    3.75
    NIST Table 1

  • Pressure exponent c_8 of the NIST Z equation.

    Market range Exact as printed.

    4
    NIST Table 1

  • Coefficient a_9 of the NIST Z equation.

    Market range Exact as printed.

    0
    NIST Table 1

  • Temperature exponent b_9 of the NIST Z equation.

    Market range Exact as printed.

    4
    NIST Table 1

  • Pressure exponent c_9 of the NIST Z equation.

    Market range Exact as printed.

    5
    NIST Table 1

  • Reducing temperature of the NIST Z equation.

    Market range Exact.

    100K
    NIST Eq. 3

  • Reducing pressure of the NIST Z equation.

    Market range Exact.

    1MPa
    NIST Eq. 3

  • Published test value used by the NIST Z check ratio output.

    Market range Exact as printed.

    1.243048
    NIST Table 2

  • Temperature of the NIST test point.

    Market range Exact.

    400K
    NIST Table 2

  • Pressure of the NIST test point.

    Market range Exact.

    50MPa
    NIST Table 2

  • Suction temperature of every stage (perfect intercooling back to 300 K).

    Market range Real intercoolers leave 5 to 15 K approach; not modelled.

    300K
    DOE Record 9013

  • Isentropic exponent of hydrogen in the stage work.

    Market range 1.386 to 1.41 between 2 and 100 MPa at 300 K.

    1.41
    Derived from NIST WebBook

  • Specific gas constant of hydrogen.

    Market range Exact as printed.

    2.01588g/mol
    NIST Table 1

  • Specific gas constant of hydrogen.

    Market range Exact as printed.

    8.314472J/(mol.K)
    NIST Table 1

  • Expresses the compression energy as a share of the hydrogen LHV.

    Market range 33.3 to 33.33 kWh/kg.

    33.3kWh/kg
    DOE Record 9013

  • Isentropic efficiency of reference case 1 (default).

    Market range 50 to 80 % (NREL 2014 section 4.2.2).

    80%
    NREL 2014

  • Isentropic efficiency of reference case 2.

    Market range 50 to 80 %.

    65%
    NREL 2014

  • Isentropic efficiency of reference case 3.

    Market range 50 to 80 %.

    50%
    NREL 2014

  • Electric motor efficiency, shaft to electricity.

    Market range Industrial motors 90 to 96 %.

    92%
    DOE Record 9013

  • Upper limit of the stage ratio slider; a larger value is refused.

    Market range 6:1 (NREL Vendor A) to 10:1 (PPI).

    10
    Vendor page

  • A duty needing more than 3 stages is refused.

    Market range 2 to 3 stages.

    3
    NREL 2014 and brief

  • Availability of one machine; N+1 raises the pair to 97.75 %.

    Market range No measured diaphragm fleet value cited.

    85%
    DOE target

  • Uninstalled cost anchor of the 500 bar class (discharge up to 550 bar).

    Market range No second quote in the same class cited.

    376000USD
    Vendor quote in NREL 2014

  • Reference throughput of the 500 bar class anchor.

    Market range Not applicable.

    35kg/h
    NREL 2014

  • Discharge pressure of the 500 bar class anchor, for the extrapolation output.

    Market range Not applicable.

    500bar
    NREL 2014

  • Uninstalled cost anchor of the 700 bar class (discharge above 550 bar).

    Market range No all-diaphragm 950 bar quote cited.

    514000USD
    AI

  • Reference throughput of the 700 bar class anchor, and reference size of the scaling law at the default discharge.

    Market range Not applicable.

    32kg/h
    NREL 2014

  • Discharge pressure of the 700 bar class anchor; above it the cost is extrapolated.

    Market range Not applicable.

    875bar
    NREL 2014

  • Discharge above which the 700 bar class anchor is used.

    Market range Diaphragm products in the catalogue top out at about 550 bar.

    550bar
    Modelling choice

  • Size exponent of the uninstalled cost: specific CAPEX per kg/h falls as throughput^(0.66 - 1).

    Market range 0.6 (six-tenths rule) to 0.7 in the hydrogen literature.

    0.66
    NREL 2014

  • Uninstalled to installed cost.

    Market range 1.2 (DOE) to 1.3 (NREL panel).

    1.3
    NREL 2014

  • USD 2013 to EUR at the NREL report rate.

    Market range ECB 2013 average about 1.33 USD/EUR (not cited here).

    1.35USD/EUR
    NREL 2014

  • Upper limit of the throughput; above it the input is refused.

    Market range Not applicable.

    500kg/h
    Brief

  • Lowest customized specific CAPEX accepted.

    Market range Not applicable.

    2000EUR/(kg/h)
    Input range

  • Highest customized specific CAPEX accepted.

    Market range Not applicable.

    30000EUR/(kg/h)
    Input range

  • Benchmark of the specific energy: theoretical floor of a 20 to 880 bar duty.

    Market range 1.05 to 1.47 kWh/kg from 20 bar to 350-880 bar.

    1.47kWh/kg
    DOE Record 9013

  • Benchmark of the specific energy at 880 bar.

    Market range 2.23 (440 bar) to 3.0 kWh/kg (880 bar).

    3kWh/kg
    DOE Record 9013

  • Benchmark: lowest measured station compression energy.

    Market range 1.7 to 6.4 kWh/kg.

    1.7kWh/kg
    DOE Record 9013

  • Benchmark: highest measured station compression energy.

    Market range 1.7 to 6.4 kWh/kg.

    6.4kWh/kg
    DOE Record 9013

  • Benchmark: a measured small diaphragm unit.

    Market range One measurement.

    8.3kWh/kg
    NREL 2014

  • Reference order of magnitude for the levelised cost of compression (not converted).

    Market range 1.48 to 1.54 USD 2007/kg.

    1.54USD/kg
    NREL 2014

  • Default of the maximum stage ratio input.

    Market range 4.2:1 to 10:1.

    6
    Derived from NREL 2014

  • Default utilization.

    Market range Early stations 10 to 50 %; mature 80 %.

    80%
    DOE Record 18003

  • Default discount rate.

    Market range No independent range cited.

    7%
    DOE Record 18003

  • Default economic life, also exported as the asset life.

    Market range No service-life source established.

    10years
    DOE Record 18003

  • Default electricity price.

    Market range 0.05 to 0.30 EUR/kWh across EU bands and countries.

    0.18EUR/kWh
    Eurostat

  • Default O&M share of installed CAPEX.

    Market range Above 4 % for diaphragm units (NREL 2014 maintenance range).

    4%/year
    DOE target