Inputs

Connected lighting load W Enter a numeric project value in W at or above 0.01. Baseline operating hours h/day Enter a numeric project value in h/day between 0 and 24. Operating days per year days/year Enter a numeric project value in days/year between 1 and 366. Daylight-affected hours h/day Enter a numeric project value in h/day between 0 and 24. Dimming reduction during daylight hours % Enter a numeric project value in % between 0 and 100. Control effectiveness % Enter a numeric project value in % between 0 and 100. Energy tariff $/kWh Enter a numeric project value in $/kWh at or above 0.

Baseline annual energy -- kWh/year

Controlled annual energy -- kWh/year

Annual energy savings -- kWh/year

Annual cost savings -- $/year

Calculation details

Baseline annual energy: -- kWh/year
Controlled annual energy: -- kWh/year
Annual energy savings: -- kWh/year
Annual cost savings: -- $/year
Effective daylight reduction: -- %

Important notes

Daylight availability, commissioning settings, override behavior, and tariffs are dated planning assumptions.
Use measured operating data or daylight modelling where project decisions require stronger evidence.

Formulas

$\displaystyle \eta_{\mathrm{effective}} = r_{\mathrm{dimming}} \times \eta_{\mathrm{control}} / 100$
$\displaystyle h_{\mathrm{daylight}} = \min(h_{\mathrm{daylight}}, h_{\mathrm{baseline}})$
$\displaystyle S_E = P \times h_{\mathrm{daylight}} \times d \times \eta_{\mathrm{effective}} / 100000$

Estimate annual lighting energy and cost savings from daylight-linked dimming assumptions and a dated tariff.

Daylight Control Savings Calculator is a planning aid. Keep the target source, product data, measurement method, and project assumptions with the result. Confirm compliance, installation, certification, and safety decisions with the responsible professional.

Inputs

Results

Formulas

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