Thermowatt Ltd. has been using a patented innovation to generate power from wastewater heat (patent date: September 2010). We offer a solution that makes building operation cheaper in terms of energy costs.

This is a state-of-the-art, environmentally friendly and cost-effective solution for heating and cooling buildings. The system is based on a heat pump, an equipment now commonly used for supplying heat energy to buildings. 


Technology process

Part of the wastewater is channelled from the main collector to a reinforced concrete chamber. This chamber can be located in- or outside the building above or below the ground. The chamber is a unit separate from the main collector line but it should be placed as close to it as possible.

The water flowing into the chamber passes through a filter station that removes solid particles from it. Solid particles enter a closed system and are subsequently returned to the main collector line. They are washed back to the sewage network by heat-extracted wastewater returning to the line. As a result, the solid particles of wastewater need to be neither deposited nor transported, while permanent water flow makes the system completely odourless.

The filtered water enters high-performance heat exchangers. Filtering aims to prevent the blocking of heat exchangers.

Filtered raw wastewater is running through the primary side of the heat exchanger, while the medium (water, water with glycol, etc.) is running through its secondary side. The heat energy recovered from the wastewater is transferred to the medium of adequate temperature by a water/water heat pump with a compressor unit.

Otherwise, the engine room of the heat pump has the components of a standard engine room.

As performance requirements and average wastewater loads are not the same at all times, a buffer storage tank may be required to manage the differences.

The system is easy to access and easy to maintain which is a key benefit for operators. 

Bisnode is well-known for providing up-to-date and reliable information on companies all over Europe. In Sweden, Bisnode controls the world's first credit-evaluation system for companies, launched in 1989. In 2014 Bisnode qualified THERMOWATT Ltd. as a creditworthy company.