Quick answer: Smart lighting saves energy by reducing unnecessary operating time and light output. According to the DesignLights Consortium, networked controls saved an average of 47% of lighting energy in its building sample, excluding savings from changing the light source (DLC report).
That average is a comparison point, not an industrial-site forecast. This guide separates fixture replacement from controls, compares the available evidence, and shows how to turn an assumed reduction into an electricity-cost estimate. Warehouse findings are identified separately from broader commercial-building research.
Separate LED replacement savings from controls savings
Calculate the fixture change and the controls change against clearly defined baselines. According to the DLC report, its controls analysis covered 114 North American buildings and excluded light-source replacement savings. The sample was not random, so its results do not establish an average for every building.
For a project estimate, compare the existing lighting with replacement fixtures operating on the same schedule. Then apply an assumed controls reduction to the replacement lighting's energy use. Adding percentages calculated against different baselines overstates the result.
Use the LED savings calculator for a preliminary lamp-replacement comparison. Keep the controls estimate separate, and use the proposed fixture wattages when preparing the project budget. A controls percentage describes lighting energy, not the entire facility bill.
Choose the control strategy that matches the space
Match the control to the avoidable use. According to the federal lighting-controls guide, occupancy sensing, time scheduling, daylight dimming, bi-level switching and demand limiting are distinct strategies with different suitability by space. Daylight dimming uses ambient-light sensors to adjust nearby lights.
The table provides research context for comparing strategies. All savings figures below are from a single Lawrence Berkeley National Laboratory meta-analysis; they are alternatives to compare, not percentages to add.
| Strategy | What it adjusts | Best-estimate average savings, according to LBNL |
|---|---|---|
| Occupancy sensing | Lighting in response to occupied or vacant space | 24% |
| Daylighting | Electric lighting in response to available daylight | 28% |
| Personal tuning | Light output to suit individual preferences | 31% |
| Institutional tuning | Light output to suit the organisation's requirements | 36% |
| Multiple approaches | Combined control strategies | 38% |
According to LBNL's study, these estimates drew on 240 savings estimates from 88 papers and case studies about commercial buildings. They are not an industrial-only dataset. Use the categories to identify what your proposal actually includes before comparing its savings claim with the research.
Prioritise warehouse zones with variable occupancy
Start the assessment where lighting hours and occupied hours differ most. According to the DLC report, the greatest savings occurred at sites with long operating hours, large swings in occupancy and less than full occupancy.
The same DLC report found savings of 75% to 88% in four warehouses using two networked-control products across multiple end users. That is a small sample, not a promise for another warehouse or a manufacturing line.
For an assessment, separate continuously occupied production areas from intermittently visited storage aisles. Ask whether the proposed zoning lets those spaces respond independently. A warehouse result is a useful reason to investigate idle lighting; it is not a substitute for your own occupancy schedule and baseline consumption.
Treat daylight savings models as estimates
Budget from the distinction between measured and modelled results. According to the LBNL meta-analysis published by ACEEE, daylighting savings in actual installations were 28%, compared with 48% in simulations and calculations.
A proposal based on a daylight model should therefore identify its assumptions and how the installed result will be measured. For your own comparison, isolate the daylight-responsive area and compare its lighting consumption under comparable operating conditions. Do not apply a daylight-zone estimate to the whole building without accounting for the remaining zones.
That research comparison does not supply a universal correction factor. It shows why an attractive simulation result and a measured electricity reduction should be presented as different kinds of evidence.
Make commissioning part of the savings plan
The enabled features and settings are part of the result. According to the DLC report, high-end trim has a substantial effect on savings, shorter occupancy timeouts save more than longer ones, and poor configuration can leave controls with minimal savings or even increased energy use.
High-end trim sets an upper output limit; an occupancy timeout determines how long the lights remain on after the last detection. Evaluate both against the work performed in the space. A useful acceptance check is whether lighting responds correctly during occupied work, vacancies and manual overrides, while providing the required task illumination.
Request a demonstration of those behaviours before accepting the savings estimate. Buying the control hardware alone does not establish which functions are enabled or what energy reduction they deliver.
Work out the electricity savings with assumed numbers
Multiply lighting energy saved by the electricity rate. The electricity cost calculator uses watts × quantity × hours ÷ 1,000 for daily kWh, then daily kWh × days per month for monthly energy. Its annual estimate multiplies monthly energy by 12.
Assumed inputs: 40 existing LED fixtures at 100 W each, operating 10 hours per day for 30 days per month, electricity at $0.15/kWh, and a controls-only energy reduction of 30%. These are example inputs, not measured performance or a tariff quote. Using the calculator's planning figure of 30 days per month gives 30 × 12 = 360 operating days for this annualised example.
- Total power = fixture watts × quantity = 100 × 40 = 4,000 W.
- Daily energy = total watts × hours ÷ 1,000 = 4,000 × 10 ÷ 1,000 = 40 kWh.
- Monthly energy = daily energy × days = 40 × 30 = 1,200 kWh.
- Annual energy = monthly energy × 12 = 1,200 × 12 = 14,400 kWh.
- Baseline annual cost = annual energy × rate = 14,400 × $0.15 = $2,160.
- Controls energy saved = baseline energy × assumed reduction = 14,400 × 0.30 = 4,320 kWh/year.
- Remaining energy = baseline minus saved energy = 14,400 − 4,320 = 10,080 kWh/year.
- Annual cost saved = saved energy × rate = 4,320 × $0.15 = $648.
- Remaining annual cost = remaining energy × rate = 10,080 × $0.15 = $1,512.
This calculation covers lighting electricity at the assumed flat rate. It excludes installation, maintenance, subscription costs and demand charges. Keep those outside the energy calculation, then include applicable costs in the project budget.
Check compatibility and scheduling before ordering
Decide whether the space needs a timer, sensors or dimming before specifying hardware. According to FEMP's occupancy-sensor guide, spaces occupied steadily during the day and empty on a predictable nightly schedule may be better served by timer controls. The guide also says adding dimming or bi-level capability to most fluorescent and LED lamps requires a suitable multi-level ballast or driver replacement.
- Compare the proposed schedule with actual occupied and unoccupied periods.
- Identify which zones need occupancy response and which need daylight response.
- Confirm that the fixture's driver supports the specified dimming function.
- Include configuration and an occupied-space demonstration in the installation scope.
Use a qualified electrician for mains-voltage wiring or driver replacement.
FAQ
How much will smart lighting save in my factory?
There is no factory-wide percentage established by this evidence. According to the DLC report, site characteristics strongly influence controls savings; use your lighting consumption and occupancy pattern to build the estimate.
Do LED lamps automatically include smart controls?
Treat the fixture and its control functions as separate specification items. According to FEMP, adding dimming or bi-level operation can require a different ballast or driver, so an LED replacement alone does not establish that capability.
Can I add occupancy and daylight savings percentages?
No: that can count the same avoided energy twice. According to LBNL, multiple approaches averaged 38%; this was a separate category, not the sum of the individual strategy averages.
Should every warehouse use occupancy sensors?
Choose from its operating pattern. According to FEMP, a predictable occupied-day and empty-night schedule may favour timers instead.
Why might a system save less than its sales estimate?
Settings and enabled functions can change the outcome. According to the DLC report, poor configuration can produce minimal savings or even increase consumption; verify the installed behaviour and measure the result against the stated baseline.
Jack Shi
Founder & editor, LEDaskJack Shi builds and writes LEDask, an independent LED-lighting tools project operated by clooms. He designs the calculators, checks their formulas and reference values against published engineering data, and writes the guides across the site.
