In times of high electricity costs, many people are anxious to save as much energy as possible. However, it is particularly difficult to save electricity in the autumn and winter months because the days are short and we need artificial light more often. LEDs have been advertised as power-saving miracles for years, but how much power do LEDs actually use? Here we clarify.
Saving electricity everywhere: LEDs are more widespread than ever before
LEDs are now used in many possible and impossible places.
Image: © Pexels/Matheus Bertelli 2022
LEDs (Light-Emitting Diodes) have been used in more and more devices and areas for years: in mobile phone displays, in televisions or monitors, in car headlights and, of course, in interior and exterior lighting.
The turnover of the global LED lighting industry is said to be noisy according to a study by Strategies Unlimited 2022 at more than 45 billion dollars. Sales have more than doubled since 2017. There are two main reasons why LEDs are used so frequently: firstly, their extremely small size, and secondly, their comparatively high efficiency. No other modern illuminant converts so little energy into so much light. That was not always so.
LEDs have been around since 1962, but only further developments in light output and color in the last 20 years have led to their triumphant advance.
Reduced consumption due to less heat
Due to new EU regulations, the sale of many types of lamps is now prohibited. The first victim was the classic filament lamp, whose time finally came to an end at the end of 2012. It got its name with good reason: it produced light by making a metal thread glow and thus glow.
Surely you have tried to unscrew such a lightbulb immediately after switching off the lamp. You have probably experienced the inefficiency of this light source firsthand. Because most of the energy, approx. 95 percent, is converted into heat instead of light – and is lost for the actual purpose.
The efficiency of a light bulb is only about 5 percent. Halogen lamps achieve a doubling to around 10 percent, energy-saving lamps achieve an efficiency of up to 25 percent. LED lamps are 30 to 40 percent.
The manufacturer Philips offers LED lights that replace 60-watt light bulbs.
Image: © Philips 2022
Because there were no other common light sources for a long time, the power of incandescent lamps was usually given in watts (W). So the 60-watt lightbulb was the standard we all knew. Such comparative information can still be found on many packaging today.
But because these 60 watts indicate the energy supplied and LEDs produce much more light from less energy, this specification no longer applies today. In the meantime, the actual light output in lumens (lm) is also on the packaging – a much more appropriate value. Together with the actual energy output (W), it is easy to compare which illuminant achieves the same brightness with less energy consumption.
How much electricity do LED lamps use?
When it comes to power consumption, the old light bulb doesn’t stand a chance against an LED.
Image: © Adobe Stock/Gualtiero Boffi 2019
The efficiency of an LED light results from two factors:
- Light output (lm)
- Energy output (W)
A more efficient lamp uses less electricity for the same amount of light. If the actual energy output is not specified on the bulb’s box or you are not sure whether the information is correct, use an energy meter or a smart socket with a measuring function. But keep in mind that the lamp and the cable can also have a certain loss of power and the measured value can be slightly higher as a result.
A calculation example
A conventional 60-watt light bulb generated a light output of around 720 lumens with these 60 watts, while a comparable Philips LED lamp around 806 lumens with 6.5 watts (according to the manufacturer’s information). This means that the light bulb consumes almost ten times as much electricity as the comparable LED light!
In terms of annual consumption, it looks like this: The light bulb consumes 0.06 kilowatts (kW) per hour. If it is switched on 6 hours a day, 365 days a year, that results in 131.4 kWh. With an average electricity price of 42 cents per kWh (as of the second half of 2022), the costs are just over 55 euros per year.
The comparable LED light consumes only 14.2 kWh for the same service life and thus costs a little less than 6 euros per year.
You can calculate the annual electricity consumption of a lamp using the following formula:
Power (in watts) × operating time (in hours) × 365 (days) = annual consumption (in watt hours)
To calculate the annual electricity costs for this lamp, you first divide the watt-hour value by 1,000 to get kilowatt-hours. You multiply this value by the current electricity price per kilowatt hour.
New energy label helps with LED selection
Green light for the new electrical device: Look out for the EU energy label when buying.
Image: © viperagp – stock.adobe.com 2021
Even if LEDs are very efficient compared to other light sources, there are differences in efficiency between the various models. The energy label renewed by the EU, which makes the differences much clearer and no longer provides a “+” sign in the energy efficiency classes, helps with the selection.
According to the old label, all LEDs had at least energy efficiency class A, and many also had A+ or A++. With the new energy label, many lamps are classified significantly lower because the limit values of the individual classes have risen sharply and have been divided up more finely.
With the EU energy label tool you can easily compare several lamps with each other. It may turn out that a model with high energy efficiency is more economical overall despite the higher purchase price. The website also provides detailed information on the efficiency classes.
- Lightbulbs converted most of the energy into heat rather than light.
- The efficiency of LED lamps compared to incandescent bulbs is many times higher.
- When buying, pay attention to the new EU energy label with the energy efficiency classes from A to G.
- Use the EU’s energy label tool to compare multiple light sources.
- Calculate the power consumption of a light bulb per year based on power and usage time.
- Use a power meter or smart sockets to determine the exact power consumption.