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Solar Battery Sizing Calculator — Canada

Size an energy reserve for an explicitly selected critical load, rather than assume that the battery can supply every household circuit. CAD planning view; stated limitations apply.

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Inputs

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Result

Updates as valid inputs change.

Calculated locally
Illustrative defaults are not local quotes or verified legal rules. Dated reference components and user-entered assumptions are explicitly distinguished. Professional review is pending.
Middle cost scenario
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Required nameplate storage, kWh
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Whole battery modules
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Installed nameplate storage, kWh
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Modeled usable delivered energy, kWh
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Material cost
—
Labor allowance
—
Delivery allowance
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Other specified costs
—
Entered tax allowance
—
Low cost scenario
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High cost scenario
—

Saved locally, explained clearly

Drafts, calculations, scenarios, and workflow progress stay in this browser unless you export them.

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Calculation steps

Follow what happened from the selected formula to the displayed answer.

Show substituted values and intermediate working
Calculate current inputs to see the working.
  1. 1

    Formula selected

    The calculator uses the following formula or method.

    required nameplate kWh = critical load × days ÷ (usable fraction × discharge efficiency).

    Inputs are converted to canonical units before evaluating this stated formula.

  2. 2

    Values entered

    Your values are placed into the calculation.

    Enter values to see what is used in this step.

  3. 3

    Result calculated

    The formula or method produces the following result values.

    Results will appear after a successful calculation.

  4. 4

    Answer formatted

    Displayed values are rounded and formatted using each output’s configured precision.

Scenario comparison

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Recent calculations

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Data and privacy

How it works

Size an energy reserve for an explicitly selected critical load, rather than assume that the battery can supply every household circuit.

This is the Canada planning view, with monetary inputs and outputs in CAD. A currency label does not establish that a tax rate, construction price, coverage rule or legal limit has been verified locally. The inputs and limitations below describe the actual scope.

Input query strings and outputs

Use an input name in this page’s URL as ?name=value, and join additional inputs with &. Portable shared links may instead use the compact ?ac= state parameter.

Input query strings

12
  • ?criticalDailyUse= Critical daily load, kWh

    Number · Required · Default: 10

  • ?autonomyDays= Target autonomy, days

    Number · Required · Default: 1

  • ?usablePercent= Usable depth of discharge

    Percentage · Required · Default: 90

  • ?dischargeEfficiency= Discharge efficiency

    Percentage · Required · Default: 95

  • ?moduleCapacity= One battery module, nameplate kWh

    Number · Required · Default: 5

  • ?unitRate= Material price per module

    Money · Required · Default: 0

  • ?laborCost= Total labor allowance

    Money · Required · Default: 0

  • ?deliveryCost= Delivery allowance

    Money · Required · Default: 0

  • ?otherCost= Other fixed costs

    Money · Required · Default: 0

  • ?costMultiplier= Material/labor multiplier

    Number · Required · Default: 1

  • ?spreadPercent= Low/high sensitivity around the entered total

    Percentage · Required · Default: 15

  • ?taxRate= Explicit tax allowance

    Percentage · Required · Default: 0

Outputs

12
  • requiredNameplate Required nameplate storage, kWh

    Number

  • modules Whole battery modules

    Number

  • installedCapacity Installed nameplate storage, kWh

    Number

  • deliveredEnergy Modeled usable delivered energy, kWh

    Number

  • materialCost Material cost

    Currency · Currency: CAD

  • laborCost Labor allowance

    Currency · Currency: CAD

  • deliveryCost Delivery allowance

    Currency · Currency: CAD

  • otherCost Other specified costs

    Currency · Currency: CAD

  • tax Entered tax allowance

    Currency · Currency: CAD

  • low Low cost scenario

    Currency · Currency: CAD

  • mid Middle cost scenario

    Currency · Primary output · Currency: CAD

  • high High cost scenario

    Currency · Currency: CAD

Formula

required nameplate kWh = critical load × days ÷ (usable fraction × discharge efficiency).

Calculations retain numeric precision internally. Displayed values are rounded for readability. Quantities that must be purchased as whole units are rounded up only where the formula explicitly requires it.

Read the inputs before calculating

  • Critical daily load, kWh: Enter the quantity described by the label.
  • Target autonomy, days: Enter the quantity described by the label.
  • Usable depth of discharge: Enter the quantity described by the label.
  • Discharge efficiency: Enter the quantity described by the label.
  • One battery module, nameplate kWh: Enter the quantity described by the label.
  • Material price per module: Zero means unpriced, not free. Enter a current, scoped supplier quote.
  • Total labor allowance: Enter the quantity described by the label.
  • Delivery allowance: Enter the quantity described by the label.
  • Other fixed costs: Enter the quantity described by the label.
  • Material/labor multiplier: Use a verified regional index only when supplied. 1 is an unadjusted scenario, not a researched index.
  • Low/high sensitivity around the entered total: Enter the quantity described by the label.
  • Explicit tax allowance: Enter the quantity described by the label.

Reproducible worked example

The following is a fictional arithmetic example, not a local quote, a verified claimant or a market forecast. Its values are included so the formula can be checked. The form does not automatically confirm any verification checkbox.

InputExample value
Critical daily load, kWh10
Target autonomy, days1
Usable depth of discharge90
Discharge efficiency95
One battery module, nameplate kWh5
Material price per module0
Total labor allowance0
Delivery allowance0
Other fixed costs0
Material/labor multiplier1
Low/high sensitivity around the entered total15
Explicit tax allowance0
OutputCalculated result
Required nameplate storage, kWh11.6959
Whole battery modules3
Installed nameplate storage, kWh15
Modeled usable delivered energy, kWh12.825
Material costCAD 0
Labor allowanceCAD 0
Delivery allowanceCAD 0
Other specified costsCAD 0
Entered tax allowanceCAD 0
Low cost scenarioCAD 0
Middle cost scenarioCAD 0
High cost scenarioCAD 0

Interpreting a changed assumption

Start with one complete scenario and change only one input when diagnosing a difference. Recheck units, the period of every rate, whether an amount is recurring or one-off, and whether a cost is already included elsewhere. A larger calculated benefit is not evidence that an assumption is more likely to occur.

Limitations

  • Material is unpriced. A zero material price is not evidence that the material is free.
  • Prices and the tax allowance are user-entered planning assumptions, not a verified local quote. Low/high outputs are sensitivity scenarios, not market confidence limits.
  • The multiplier applies only to material and labor; delivery and fixed costs are not multiplied.
  • Energy capacity does not establish inverter power, surge capability, transfer-switch compatibility, or safe backup duration in severe weather.

Frequently asked questions

What does this Solar Battery Sizing result represent?

Size an energy reserve for an explicitly selected critical load, rather than assume that the battery can supply every household circuit. It applies the displayed formula to your inputs; it does not infer omitted facts.

No. Numeric defaults are illustrative unless an input or dated reference explicitly identifies a researched component. Currency is CAD; local quotes, eligibility and unsupported rules must be entered and verified separately.

What must I check before relying on the result?

Check the input units, supplier or authority evidence, the stated model exclusions and the period used for costs. This arithmetic does not supply missing site-specific design or local legal rules.

Can I compare or share different assumptions?

Change one assumption at a time and use the browser-local project or share controls. A shared URL contains the encoded input values; do not include information you do not wish to disclose.

Sources and reference scope

  • DOE energy-use arithmetic — retrieved 2026-09-24. Energy consumption versus power; not a local tariff or an approval of this implementation.
  • PVWatts: site-specific solar estimation — retrieved 2026-09-24. External site-yield model. AskCalculators uses your entered yield; it does not call or reproduce PVWatts.
  • DOE insulation overview — retrieved 2026-09-24. Insulation and thermal resistance concepts; not structural or code approval.

These references support only their stated scope. They are not evidence that every local rule or price needed by the master expansion has been loaded.

Sources
Limitations
  • Illustrative defaults are not local quotes or verified legal rules. Dated reference components and user-entered assumptions are explicitly distinguished. Professional review is pending.
  • Inputs are converted to canonical units before evaluating this stated formula.
  • Material quantities are estimates. Confirm site dimensions, product coverage, waste, and local requirements before ordering or construction.
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