As the days grow shorter, the electricity bill climbs. Lights run longer, circulation pumps work non-stop, and the occasional fan heater kicks in. Before you guess, do the math: with our Calculate electricity costs you can see in minutes which appliances really cost you. In this guide we get to the root of the causes – including the invisible ones.
Why more electricity flows during the heating season
There are several reasons for the rise. It gets dark earlier, so lights burn longer. You spend more time indoors and use entertainment electronics more intensively. And the heating system itself needs power: circulation pumps move the hot water, and controls run around the clock.
You can estimate how much this affects your overall heating costs with the Heating cost calculator. That way you separate the electricity demand from the actual heat demand and see where to start first.
Tracking down hidden loads
Some costs are barely noticeable because they add up over weeks. Typical candidates:
- Standby consumption: TVs, routers, chargers and plug-in power supplies draw current even at rest – 24 hours a day.
- Old circulation pumps: Unregulated pumps of older design can consume a multiple of modern high-efficiency pumps and run throughout the entire heating season.
- Fan heaters: They warm up quickly but draw a lot of power. As a permanent solution they are almost always the most expensive way to heat.
Lighting: LEDs pay off now
Especially in the dark half of the year, when lights burn for many hours, switching from incandescent bulbs to LED makes the biggest difference. The effect is far greater in winter than in summer because the operating time increases. The LED savings calculator shows exactly how much you save.
Line losses: the invisible heat in the wall
An often overlooked point: every current-carrying cable produces a power loss that dissipates as heat. Physically, P = I²·R applies – the power loss grows with the square of the current and with the cable's resistance. With long, thin cables under continuous load, this adds up.
An example makes it tangible: if 16 A flow through a 20 m cable with a 2.5 mm² copper cross-section, roughly 73 W of continuous loss arises – energy you pay for without any benefit. Over an entire heating season with continuous loads, that mounts up. Use the Calculate cable power loss to work through your specific case.
What you can do about it
- For permanently installed continuous loads, a larger cross-section or a shorter cable route pays off – both lower the resistance.
- Avoid long extension cords with thin cross-sections for devices that run continuously.
- Check whether a load can be placed closer to the distribution board.
Save in practice: calculate first, then act
The most important step is not to estimate but to calculate. Note the power rating of your main appliances and their daily operating hours, and know your electricity price per kilowatt-hour – without it no saving can be quantified. Work through each device individually instead of judging in general terms. Often it is a few continuous loads that make up the lion's share. Anyone who consistently switches off standby, replaces old pumps, moves to LED and keeps an eye on line losses under continuous load will get through the cold season noticeably cheaper.
