LED Signage Electricity Consumption and Running Costs

Use the complete system's input power

Watts describe power; kilowatt-hours describe energy used over time. A power supply's rated output capacity is not automatically the installation's actual consumption. Ask the supplier for the input power of the complete sign, including power supplies and any controllers, at the intended lighting setting.

If the figure covers only LED modules, ask what else must be included. If it is a maximum rather than an expected operating value, record that distinction in the estimate. RGB settings, changing brightness and controllers can make a single operating figure less representative.

Power also does not tell you how legible a finished sign will be. Germany's Verbraucherzentrale explains the distinction between power in watts and light output in lumens in its LED lighting guide (German).

Calculate kWh before calculating the cost

Energy in kWh = total input power in watts ÷ 1,000 × operating hours. Electricity cost = energy in kWh × price per kWh. For an annual estimate, multiply the hours per operating day by the number of operating days in the year.

For example, 100 W ÷ 1,000 × 8 hours = 0.8 kWh per day. At an assumed €0.30 per kWh, that is €0.24 per day. If it runs on 300 days, the result is 240 kWh and €72 per year.

Replace the assumed tariff with your own price per kWh and use a consistent tax basis. This calculation covers consumption charges; it excludes standing charges, maintenance and other project costs. Where schedules or tariffs vary, calculate each period separately and add the totals.

Worked examples with different operating schedules

The following are hypothetical calculations, not measured product specifications or current electricity offers. Each uses an assumed €0.30 per kWh. The wattages describe total system input power.

• 60 W × 8 hours × 300 days ÷ 1,000 = 144 kWh per year; €43.20.
• 120 W × 10 hours × 365 days ÷ 1,000 = 438 kWh per year; €131.40.
• 240 W × 12 hours × 365 days ÷ 1,000 = 1,051.2 kWh per year; €315.36.

Assess operating hours and dimming

At the same input power, fewer operating hours reduce consumption in direct proportion. In the 120 W example, changing from ten to eight hours on 365 days reduces use by 87.6 kWh, worth €26.28 at the assumed tariff. Choose a schedule that fits the intended visibility and the conditions agreed for the site.

Do not assume a dimmer marked 50% makes the complete installation consume exactly half the power. Ask for an operating value at the chosen setting or have consumption measured. Include any standby consumption outside the illuminated hours separately.

For a permanent outdoor installation, agree how controls and power supplies can be accessed for service. Signage installation planning should cover this before the sign is manufactured.

Request the figures with the signage quote

Ask for the complete system's input power, the lighting setting used for that figure, whether it is measured or estimated, and whether standby consumption is included. Add your planned operating hours, operating days and tariff to make the estimate specific to your business.

For several locations, calculate each site's sign quantity, power and schedule separately before adding the results. A repeated brand design does not necessarily mean identical sign dimensions or running hours at every address.

Use the illuminated signage overview to compare suitable sign types. For the initial purchase, the custom signage cost guide covers design, construction, delivery and mounting; keep those costs separate from electricity consumption.