Live Demo — LED Energy Consumption Calculator
Enter your luminaire power, LED driver efficiency, unit count and multi-period dimming schedule to get the daily energy load instantly.
LED Energy Consumption Calculator
Free professional calculator for LED luminaire energy consumption, the starting point of every solar street lighting load design. Input the luminaire rated power, LED driver efficiency and number of units, then define your night-time dimming schedule to compute daily, system and monthly energy consumption in watt-hours, and see how smart dimming cuts the panel and battery budget.
Key Features
Luminaire Parameters
Set rated power (W), LED driver efficiency and the number of luminaires in the single-unit or full system.
Multi-Period Dimming Schedule
Model up to three operating periods with duration (h) and power ratio (0-100%) to reflect real late-night dimming.
Daily Energy Calculation
Calculates daily watt-hours including driver losses using E_daily = P_rated/η_driver × Σ(ti × di).
System & Monthly Totals
Scales the result to the whole lighting system (n luminaires) and to a 30-day monthly energy figure.
PV / Battery Matching
Checks the daily charging requirement from system efficiency and estimates battery capacity from autonomy days.
Engineering Reference
Built-in table of common powers and recommended dimming profiles for arterial, secondary, branch and residential roads.
Technical Specifications
| Platform | HTML5 Web App | Android (via WebView) |
| Core Calculation | E_daily = P_rated / η_driver × Σ(ti × di) |
| Luminaire Power | 15 - 120W typical (user-defined) |
| Driver Efficiency | 88% - 92% |
| Dimming Periods | Up to 3 periods, power ratio 0 - 100% |
| Lighting Time | Per-period duration, up to 11h/day |
| Number of Luminaires | Single or system (n units) |
| System Efficiency | Approx. 0.8 (PV / battery matching) |
| Monthly Energy | E_month = E_total × 30 |
| Industry Standards | IES LM-79-19, EN 13201, IEC 63103 |
| Output | Daily / system / monthly energy (Wh and kWh) |
Frequently Asked Questions
How is daily LED energy consumption calculated?
The actual driving power is computed as P_rated / η_driver to include LED driver losses, then multiplied by the lighting schedule: E_daily = (P_rated / η_driver) × (t1×d1 + t2×d2 + ... + tn×dn), where ti is each period duration in hours and di its power ratio.
Why does the LED driver efficiency matter?
The driver converts mains or battery power with an efficiency of roughly 88-92%, so the actual input power is higher than the luminaire rating. A 60W luminaire with 0.9 driver efficiency draws about 66.7W, and ignoring this loss would understate the real system load.
How much energy does dimming save?
Smart late-night dimming typically saves 40-50% of energy without compromising traffic safety. For example an 11h schedule at 100%, 50% and 30% consumes 6.1 equivalent full-power hours versus 11, reducing daily energy from about 734 Wh to 407 Wh for a 60W luminaire.
Why is this the starting point for solar system sizing?
The luminaire load determines the daily charging energy (E_charge = E_total / η_sys) and battery capacity (C = E_total × N / (V × DOD)). Precise energy consumption directly drives the required solar panel and battery size in the rest of the system design.
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