You’re probably familiar with it: your smartphone’s power adapter is always neatly plugged in on the sideboard or bedside table. But what about the energy costs if the power adapter is left plugged in all the time? And is this perhaps even a fire risk? nextpit looks into this and reveals the answer in this article.
How much does a power supply unit really cost?
The fact is: Every power adapter draws power as long as it is plugged into the socket, regardless of whether the smartphone is charging or not. The reason? The integrated transformer, which converts the current from the 230 volts in the socket to the reduced voltage for your device, even in standby mode.
Here’s the good news: if you use a high-quality power supply from a reputable manufacturer, the costs for standby mode are negligible. An EU regulation stipulates that power supply units with an output of 50 watts or less may consume a maximum of 0.3 watts in standby mode. That’s around 2.6 kilowatt hours per year, which costs you around one euro.
This regulation was made even stricter in 2020: Power supply units up to 50 watts may now only consume 0.1 watts in standby mode. This means around 0.9 kilowatt hours or around 40 cents per year. Power supply units with a higher output must comply with a maximum standby consumption of 0.21 watts.
Individually, the costs per smartphone are therefore minimal and hardly noticeable on your electricity bill. Looking at the global perspective, however, there is considerable potential for savings: if only all 69 million smartphone users in Germany were to unplug their adapters after charging, over 27 million euros could be saved every year.
Is a plugged-in power adapter really dangerous?
With high-quality power adapters from well-known manufacturers, you can rest assured: These are designed so that they do not overheat in standby mode. However, you should be careful with no-name products. They often skimp on materials and fire protection. If your power supply unit gets unusually warm or makes a humming noise, you should definitely stop using it.
The original power supply units from the manufacturers are generally harmless, but the same applies here: pay attention to authenticity when buying, as counterfeits, especially Samsung and Apple power supply units, are widespread. In addition to the manufacturers themselves, brands such as Anker also offer high-quality power adapters that can improve your safety and charging experience.
