Microgrid Black Start Fuel Autonomy Calculator

Estimate how many hours a microgrid can sustain black start operations based on stored fuel, generator specific consumption, contingency reserve, and unusable inventory.

Usable diesel, renewable diesel, or jet fuel stored onsite for black start.
Generator fleet average liters per kilowatt-hour at the planned loading point.
Aggregated kW of loads that must be energised during black start sequencing.
Defaults to 0%. Adds spinning reserve or contingency allowance on top of the critical load.
Defaults to 0%. Accounts for heel volume, sludge, or regulatory minimum inventory.

Resilience planning aid—validate against OEM black start procedures and regulatory requirements before updating contingency plans.

Examples

  • Fuel inventory 18,000 liters, specific consumption 0.23 L/kWh, critical load 2,200 kW, reserve margin 15%, unusable fuel 5% ⇒ Usable fuel: 17,100.00 liters. Hourly fuel demand: 581.90 liters/hour. Black start autonomy: 29.39 hours (1.22 days), delivering 74.04 MWh.
  • Fuel inventory 9,500 liters, specific consumption 0.27 L/kWh, critical load 1,400 kW, reserve margin left blank, unusable fuel 3% ⇒ Usable fuel: 9,215.00 liters. Hourly fuel demand: 378.00 liters/hour. Black start autonomy: 24.38 hours (1.02 days), delivering 34.13 MWh.

FAQ

How do I model multiple generator sets with different specific consumptions?

Compute a weighted average specific fuel consumption based on each unit’s planned kW contribution, or run the calculator per dispatch scenario and document the limiting case.

Can I include battery or renewable support in the autonomy calculation?

Yes. Reduce the critical load input by the firm contribution you expect from batteries or renewables during the black start window. Recalculate whenever storage availability or solar forecasts change.

Why is some fuel treated as unusable?

Storage tanks typically maintain heel volume to avoid drawing contaminants or violating regulatory minimums. Deducting unusable fuel ensures autonomy estimates remain realistic and auditable.

How should I reflect cold weather derates?

Increase the reserve margin input to capture expected derates or viscosity penalties, or adjust the specific fuel consumption value using cold-weather test data.

Additional Information

  • Result unit: hours of autonomous operation with equivalent days and delivered megawatt-hours for reporting.
  • Specific fuel consumption should reflect the loading point planned during black start sequencing, not nameplate efficiency.
  • Reserve margin input inflates both load and fuel demand to ensure spinning reserve is maintained.

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