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Solar Electricity

Solar Autonomy Calculator

This page handles the arithmetic for autonomy duration while leaving room to review units, limits, and source conditions.

Set up the Solar Autonomy case

Solar Autonomy updates live after each input change.

kWh

Enter usable battery energy in kWh.

kWh

Enter daily load in kWh.

The Solar Autonomy equation

days = usable energy ÷ daily load

Read the Solar Autonomy equation from the units on this page. A familiar symbol can shift meaning between DC, AC, energy, component, or billing work.

A clean Solar Autonomy result confirms the arithmetic for autonomy duration; it does not prove the equipment rating or source data is the right one.

Only the entries shown on Solar Autonomy feed autonomy duration. If another correction factor matters, keep it in the notes or make a separate run.

Sample Solar Autonomy run

Using the sample values, Usable battery energy = 18 kWh; Daily load = 6 kWh, the primary result is 3.00 days.

Baseline3.00 days
Change Usable battery energy15.3 kWh
New result2.55 days

This Solar Autonomy one-input test is a scale check, showing direction and sensitivity without turning the changed case into a recommendation.

If the changed usable battery energy comes from a real measurement, keep the original Solar Autonomy run so the source of the difference remains clear.

Source notes for Solar Autonomy

Treat the Solar Autonomy input panel like a short measurement log. If usable battery energy is assumed rather than measured, label it before copying autonomy duration.

EntryExampleCheck before use
Usable battery energy18 kWhEnter usable battery energy in kWh.
Daily load6 kWhEnter daily load in kWh.

If the next step shifts toward Off-Grid Battery Bank, keep that as a separate worksheet instead of forcing the numbers into Solar Autonomy.

What not to assume from Solar Autonomy

Solar input during the outage is excluded.

  • Temperature derating
  • Shading
  • Winter sun hours

When autonomy duration is close to a rating, use the stricter review path instead of relying on the extra decimals shown by Solar Autonomy.

Off-Grid Solar Array is a separate worksheet; carry over autonomy duration only with its units and source note.

Reading autonomy duration

If autonomy duration is near a limit, preserve the calculated value from Solar Autonomy and apply required margin after the calculation.

Solar Autonomy should stay tied to sun-hours, array orientation, controller limits, battery voltage, and seasonal assumptions.

Audit trail for autonomy duration

Save location assumptions, array tilt, controller model, battery voltage, and weather basis for Solar Autonomy.

If a later Solar Autonomy run changes only usable battery energy, label it as sensitivity work. Several changed conditions deserve a new baseline.

Use Solar Battery Charging for that neighboring calculation rather than adding unstated assumptions here.