PKS-THERMPIPE^® System | Wastewater heat utilisation

Energy recovery from wastewater and the ground

Wastewater contains significant potential that should not go to waste: thermal energy. PKS-THERMPIPE^® sewer pipes with an integrated heat exchanger enable the use of this renewable energy source for environmentally friendly heating and cooling of buildings. Within the framework of municipal heat planning, PKS-THERMPIPE^® provides a sustainable solution by combining wastewater heat recovery and geothermal energy in a single system.

The system primarily utilises the thermal energy of the surrounding ground, while the wastewater provides an additional heat boost. If the generated thermal energy exceeds current demand, it is transferred to the ground and stored there—similar to a battery. This principle allows the system to operate independently of daily fluctuations or irregular wastewater flow, ensuring a continuous and reliable energy supply.

Heating and cooling with up to 50% less energy

Wherever people live and work, wastewater is produced. In most cases, it is discharged into the sewer system without being utilised, even though it contains residual heat at an average temperature of around 15 °C. With PKS-THERMPIPE^®, this freely available energy can be used directly on site. The innovative sewer pipe system extracts thermal energy from both wastewater and the surrounding soil, transferring it via a secondary heating circuit to a heat pump. This enables nearby buildings—such as offices, hotels or entire residential districts—to be heated and cooled efficiently. As a result, primary energy consumption can be reduced by up to 50%.

Plan ahead today and save in the future

Even if wastewater heat utilisation is not initially considered during the planning phase of a sewer system, the heat exchanger function can be activated at a later stage. Until then, PKS-THERMPIPE^® can be operated as a conventional sewer pipe system. All PKS sewer systems are designed for a service life exceeding 100 years, making them a sustainable long-term investment.

3-in-1 function

PKS sewer pipe + wastewater heat + geothermal energy = PKS Thermpipe^® system

Profiled PKS sewer pipes have been successfully used worldwide for decades, ensuring high operational reliability in wastewater transport. Manufactured from recyclable PE 100, these plastic pipes are durable, resistant to breakage, permanently weldable and require minimal maintenance.

PKS-THERMPIPE^® pipes offer the same advantages, with the additional capability of functioning as heat exchangers. This is achieved by utilising the support pipe integrated into the outer pipe profile as a secondary heating circuit, which runs spirally around the pipe. A heat transfer fluid (brine) circulates within this system, transporting thermal energy through a fully welded PE pipe system to the heat pump.

Consistent energy supply

The primary energy source for PKS-THERMPIPE^® is the heat from the surrounding ground, complemented by additional energy input from wastewater. If more thermal energy is generated than required, it is stored in the ground for later use, similar to an energy storage system. This ensures independence from daily demand variations and irregular wastewater inflows, guaranteeing a stable energy supply.