Competitive advantages compared to existing processes: 

- Reheating largely uses renewable energy 

- Requires about 25% less electrical energy than a conventional heating rod 

- Little space required (similar to an under-counter device) 

- No noise emissions 

- Simple electrical installation

More and more houses are covering their energy requirements with renewable energies such as solar thermal energy and heat pumps. These processes involve water from a buffer tank heated to a fairly low temperature. To raise the temperature for showering, for example, the conventional method is an electrical heating rod or a second fossil-fueled heat generating system. 

The new thermoelectric water heat pump from a German university uses existing (renewable) energy from the buffer tank to provide potable water at higher temperatures. Cold potable water is first preheated with heat exchangers to almost the buffer tank temperature. Then thermoelectric elements use the buffer tank heat to bring the water to the desired higher temperature. For existing energy to be used as efficiently as possible, the thermoelectric element arrangement is similar to that of countercurrent heat exchangers. The water to be heated flows along a series of thermoelectric elements while the water from the buffer tank flows in the opposite direction. The buffer tank water cools down more and more while the potable water is warmed more and more by the thermoelectric elements.

The technology is suitable for heating water with low flow temperature to a higher desired temperature such as for showering. This is useful when the water is heated with solar thermal energy, heat pumps, low-temperature networks, or geothermal heat. In such cases, the heating rod normally used for reheating water is replaced by the thermoelectric heat pump described here. 

The university offers a license agreement to companies active in the heat pump technology, warm water treatment and flow heater and water boiler manufacturers or thermoelectric element manufacturers. If there is interest in further development of the process, the university also offers technological cooperation. 

The university offers a license agreement to companies active in the heat pump technology, warm water treatment and flow heater and water boiler manufacturers or thermoelectric element manufacturers. If there is interest in further development of the process, the university also offers technological cooperation.