Ireland version
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 Ireland planning view, with monetary inputs and outputs in EUR. 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
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?criticalDailyUse=Critical daily load, kWhNumber · Required · Default: 10
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?autonomyDays=Target autonomy, daysNumber · Required · Default: 1
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?usablePercent=Usable depth of dischargePercentage · Required · Default: 90
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?dischargeEfficiency=Discharge efficiencyPercentage · Required · Default: 95
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?moduleCapacity=One battery module, nameplate kWhNumber · Required · Default: 5
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?unitRate=Material price per moduleMoney · Required · Default: 0
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?laborCost=Total labor allowanceMoney · Required · Default: 0
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?deliveryCost=Delivery allowanceMoney · Required · Default: 0
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?otherCost=Other fixed costsMoney · Required · Default: 0
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?costMultiplier=Material/labor multiplierNumber · Required · Default: 1
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?spreadPercent=Low/high sensitivity around the entered totalPercentage · Required · Default: 15
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?taxRate=Explicit tax allowancePercentage · Required · Default: 0
Outputs
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requiredNameplateRequired nameplate storage, kWhNumber
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modulesWhole battery modulesNumber
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installedCapacityInstalled nameplate storage, kWhNumber
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deliveredEnergyModeled usable delivered energy, kWhNumber
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materialCostMaterial costCurrency · Currency: EUR
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laborCostLabor allowanceCurrency · Currency: EUR
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deliveryCostDelivery allowanceCurrency · Currency: EUR
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otherCostOther specified costsCurrency · Currency: EUR
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taxEntered tax allowanceCurrency · Currency: EUR
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lowLow cost scenarioCurrency · Currency: EUR
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midMiddle cost scenarioCurrency · Primary output · Currency: EUR
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highHigh cost scenarioCurrency · Currency: EUR
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.
| Input | Example value |
|---|---|
| Critical daily load, kWh | 10 |
| Target autonomy, days | 1 |
| Usable depth of discharge | 90 |
| Discharge efficiency | 95 |
| One battery module, nameplate kWh | 5 |
| Material price per module | 0 |
| Total labor allowance | 0 |
| Delivery allowance | 0 |
| Other fixed costs | 0 |
| Material/labor multiplier | 1 |
| Low/high sensitivity around the entered total | 15 |
| Explicit tax allowance | 0 |
| Output | Calculated result |
|---|---|
| Required nameplate storage, kWh | 11.6959 |
| Whole battery modules | 3 |
| Installed nameplate storage, kWh | 15 |
| Modeled usable delivered energy, kWh | 12.825 |
| Material cost | EUR 0 |
| Labor allowance | EUR 0 |
| Delivery allowance | EUR 0 |
| Other specified costs | EUR 0 |
| Entered tax allowance | EUR 0 |
| Low cost scenario | EUR 0 |
| Middle cost scenario | EUR 0 |
| High cost scenario | EUR 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.
Are the starting amounts verified Ireland prices or legal rules?
No. Numeric defaults are illustrative unless an input or dated reference explicitly identifies a researched component. Currency is EUR; 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.