Can we get energy from hot water?

Hot water consumption per person

  • Optimize hot water consumption per person

    Find out in our guide how high the hot water consumption per person is in this country and how you can calculate the costs yourself. You can also read why it makes sense to reduce consumption in the long term.

In order to be able to optimize the hot water consumption, you first have to know it. The hot water consumption per person in this country accounts for 25 to 40 percent of the total water consumption. With an average total consumption of water of 121 liters per day (BDEW for 2018) it is 30 to 48 liters. The large range is due to the fact that hot water is used very differently from person to person.


The hot water consumption in numbers

Daily personal hygiene accounts for the largest share of hot water consumption per person in a household. This includes showering, bathing, washing your face, etc. The above average value of 30 to 48 liters refers to this nott on the total amount of water that accumulates when showering or bathing, for example. What is meant is only the amount that is made available by a water heater such as the heater or a solar thermal system. Those who bathe more often have a higher consumption of hot water and thus also a higher total water consumption than someone who only takes a short shower every day. Because the cold water is added to the warmed up warm water.

The following figures show how closely hot water consumption (warm water) in particular and water consumption (warm and cold water) in general are related:

● Flushing the toilet accounts for almost 30 percent of total water consumption. As expected, this is cold, unheated water from the tap.
● Laundry washing accounts for a little more than 10 percent of total water consumption. In contrast to flushing the toilet, the water is partially heated - usually directly in the washing machine and with the help of electricity.
● Similar to washing clothes, some of the water is warmed up when washing the dishes. The share here is around 6 percent of the total water consumption.

Hot water consumption, drinking water consumption, useful and virtual water consumption

Anyone looking for the average hot water consumption per person will sooner or later come across corresponding terms such as drinking water, industrial water, virtual water or water footprint. But what do they mean in detail? The number of 121 liters per day mentioned at the beginning refers only to the drinkable and directly used water from the tap. Industrial water, on the other hand, also takes into account the amount that arises in the production of food or other goods - and that goes beyond national borders. This indirectly Experts also call used water virtual water. Its amount exceeds that of drinking water many times over. The Federal Environment Agency has determined a daily consumption of 117.2 billion cubic meters for Germany. This equates to the equivalent of 3.9 cubic meters or 3,900 liters per person. For the calculation of the actual Water consumption per person must therefore take into account the amount of direct and indirect water. The term water footprint is used for this.