How much can LED save a business?
Replacing fluorescent fittings with LED typically saves around 30–60% of lighting energy, and replacing metal halide high bays often 50–70%. The saving in pounds depends mostly on how many hours the lights are on and what you pay per kWh.
How the calculation works
Energy saved per year equals the number of fittings, multiplied by the watts saved per fitting, multiplied by hours per year, divided by 1,000. The bill saving is that figure multiplied by your unit rate. Simple payback is the installed cost divided by the yearly saving. It ignores maintenance savings, controls and finance, which usually improve the picture.
Worked example
A £100 installed LED panel replacing a 72 W fluorescent panel with a 36 W LED saves 36 W. At 2,500 hours a year that is 90 kWh, worth £22.50 at 25p per kWh, so simple payback is about 4.4 years before maintenance savings and controls.
Make the saving bigger
- Add presence sensors in rooms, toilets and aisles that are often empty
- Use daylight dimming near windows and roof lights
- Prioritise areas with the longest hours first
- Replace complete luminaires rather than fitting LED tubes into old gear