How much can you save by replacing fluorescent lights with LED?
The difference can be substantial in spaces where lights are on for many hours a day. Here is a simple way to estimate the savings.
READ MORE ↓LED lighting often uses much less electricity than older fluorescent lighting. The result depends on the existing luminaires, ballasts, illumination requirements and the LED solution selected.
The European Commission has estimated typical savings from replacing fluorescent lighting with LED at around 25–40% in homes and up to 52% in commercial buildings. These are indicative figures, not a guarantee of specific savings for every project.
Example: 100 lights in a commercial building
Assume that each older luminaire consumes 80 W in total, including the ballast, and that a new LED luminaire consumes 40 W. There are 100 lights, operating for 3,000 hours per year.
| Lighting | Power per luminaire | Annual consumption |
|---|---|---|
| Older fluorescent lighting | 80 W | 24,000 kWh |
| New LED lighting | 40 W | 12,000 kWh |
| Estimated savings | 40 W per luminaire | 12,000 kWh · 50% |
If the total electricity price is, for example, ISK 25/kWh this corresponds to annual savings of ISK 300,000 in this example. The electricity price is illustrative only. Use your company's actual total electricity price to estimate savings in ISK. Purchase costs, installation and maintenance are not included in this figure.
Calculate the savings for your premises
Annual savings in kWh = (old wattage − new wattage) × number of lights × operating hours per year ÷ 1,000
Then multiply the kWh savings by the total electricity price per kWh to estimate the financial savings.
What should you check before choosing LED lighting?
Power consumption of the whole system
A ballast is electrical equipment that controls and limits the current through a fluorescent tube. It also consumes electricity, so the total power consumption may exceed the wattage printed on the tubes. It is important to measure or confirm the actual power consumption of the whole system.
Light output and distribution
Do not compare wattage alone. Also consider lumens, light distribution, glare and illuminance on work surfaces.
LED tubes or new luminaires
In some cases, LED tubes can be installed in existing luminaires, but ballast compatibility varies. Replacing the entire luminaire may offer a better long-term solution. Changes to electrical equipment require assessment and implementation by appropriately qualified professionals.
Controls and sensors
Motion sensors, daylight controls and timers can further reduce consumption where lights would otherwise remain on unnecessarily.
Sources: European Commission, assessment of energy savings from LED replacement. This example was prepared by Lúxbert and is based on the assumptions set out above.
See also what lumens tell you about light output and how DALI controls work.