Aquathermal energy

Aquathermal energy is the collective term for sustainable heating and cooling using water. It involves thermal energy from surface water (TEO) or from wastewater (TEA). We use the heat from surface water or wastewater and allow colder water to flow back into the water system or sewer system.

Aquathermal energy is increasingly seen as a sustainable alternative to natural gas. The technology is becoming more prominent in the spotlight. As a water manager, HHNK is keen to promote aquathermal projects that use heat from surface water and wastewater.

TEO makes it possible to utilize heat or cold from lakes and water. TEA uses heat from sewers, sewage pumping stations, pressure pipes, and sewage treatment plants. In both cases, renewable heat and/or cold is extracted from water.

How does aquathermal energy work?

Heat is extracted from water using a heat exchanger. The heat is upgraded using a heat pump to a usable temperature for heating homes and buildings. This can be done using a collective or individual heat pump, which requires electricity. Heat is transported via a heat network.

TEO is often combined with thermal energy storage (TES). This means that hot water is stored in the summer for use in the winter. During this period, the surface water temperature is too low for heat extraction. An additional advantage of TES is that it can be used to cool a home as well as heat it. With TEA, water temperatures remain relatively high in winter, so the use of thermal energy storage is not always necessary.

Advantages

Aquathermal energy has several advantages. Starting with the energy balance. Aquathermal energy generates four times as much energy as is needed to extract the heat. This means you actually 'earn' energy.

In addition to the energy balance, aquathermal energy also has advantages for water quality. This technology not only allows dead-end ditches to flow again, but also cools them down. It also increases the oxygen content in the water, reducing the likelihood of blue-green algae growth. Cooling surface water in the summer is also beneficial for water quality in general. Finally, aquathermal energy is also very easy to integrate spatially.

This explains the increasing popularity of this heat source among municipalities, project developers, energy cooperatives, and water boards. Due to the positive effects on water quality and the general public interest, HHNK actively supports aquathermal initiatives with knowledge and advice.  

How can HHNK help you?

We have developed a viewer that allows you to discover for yourself how much heat can be extracted neighbourhood water in your neighbourhood . We also advise municipalities on aquathermal energy in the heat transition. Project developers and energy cooperatives can also contact us for tailored advice and support. We regularly perform targeted quick scans for neighborhoods or new construction sites.

It is also important to know what the consequences of aquathermal energy are for aquatic life. Due to the relative novelty of the technology, not everything is known about this yet. We are therefore conducting research into the consequences of aquathermal energy on water quality and ecology.

Viewer

HHNK developed this viewer in collaboration with the province of North Holland, the AGV Water Board, and the Rijnland Water Authority. Thanks to this collaboration, the viewer contains a wealth of information that is relevant to the application of aquathermal energy. For example, HHNK provided data on the water system and wastewater. The province also provided information on, among other things, year of construction, energy labels, new construction plans, and housing densities. Finally, the viewer includes an analysis tool that shows whether sufficient heat from water is available for a selected location. 

Aquathermal viewer

Sample projects

• HHNK recently collaborated on the development of theZaanse Heldenin Zaandam. This apartment complex will be heated entirely using aquathermal energy from the Zaan River. 
• Aquathermal energy is now also being installed in theHolenkwartierdistrict in Hoorn. 

More information

For frequently asked questions and more detailed information about aquathermal energy, please visit theAquathermal Energy Network website at.