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Lighting Retrofit Payback Calculator

Simple payback, lifetime net saving, and return on capital for a lighting upgrade, with incentive support.

Inputs

Scope

Luminaires in the project scope.

Existing input watts minus retrofit input watts, per fixture.

Sets typical annual hours and a national average energy price.

Leave 0 to use the operating hours of the selected profile.

Leave 0 to use the national average price in the selected profile.

Costs

Fixture, driver, and accessory cost per position, delivered to site.

Installed labour per position, including access, disposal, and commissioning.

Utility or programme incentive received for the project.

Whole-life

Annual saving from longer life and fewer service visits. Leave 0 for an energy-only case.

Years over which lifecycle saving is measured.

Result

Net saving over the period
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Simple payback
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Return over the period
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Annual energy saving
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Energy saved
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Average monthly saving
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Total annual saving
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Installed cost
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Net cost after incentive
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Operating hours used
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Energy price used
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Reading this payback
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What to check

  • Installed cost including access equipment, disposal, control commissioning, and downtime
  • Savings verified after commissioning, not the modelled saving in the proposal
  • Incentive terms: pre-approval requirements, measurement rules, and payment timing

Related calculators

This calculator is a first-pass screen using simple payback without discounting. Verify installed cost from contractor returns, savings from a post-commissioning measurement, and the incentive terms before the project is committed to a budget.

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Keep the assumptions with the result.

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