The source of energy lies directly below us.
The largest energy leak in a house is the wastewater!
The sewage canals and treatment of wastewater is one of the great achievements of the modern world. In the canals, all of the wastewater flows together, which is produced in private households and in the industry and trade.
Five thousand people already ensure there is a continuous stream of wastewater, which reaches 15 litres per second. The temperature of the water that leaves the households, after it has been used to shower, wash or to flush the toilets, amounts to approximately 20 degrees Celsius. From this, around 70kW of energy can be recovered.
In the industry, significantly warmer wastewater is produced: at temperatures of over 30 degrees Celsius. This temperature is downright predestined for the recovery of energy from wastewater, since heat pumps can work here extremely efficiently.
But also in wastewater treatment plants, similar efforts are worthwhile. At 10 degrees, the temperature of the treated wastewater is lower than when it is fed into the canals, but the amount of water is many times higher. In a treatment plant with 500,000 liters of wastewater hourly, a theoretical heat potential of 1,700 kW is available. This can heat around 300 single-family homes.