"Don't throw the baby out with the bathwater" which means 'Don't discard something valuable along with something undesirable'
This saying fits perfectly with wastewater heat recycling. The water may be dirty, but the energy within it is clean!
Don't throw out the clean energy with the dirty water!
You set the policy direction and priorities to transition to a low carbon future. You develop strategies and action plans to reach the goals and set out the time frames for this to happen. You draw the high level map to follow.
You decide how buildings will keep the occupants comfortable. How heating & cooling will be done and what energy will be used. Buildings last for a long time so your choices are important.
You provide and maintain the infrastructure to collect and transport used water to treatment facilities. You also receive and control the thermal energy contained within wastewater. You are therefore a potential energy source.
Note: The terms 'Wastewater' and 'sewage' are both used on this site and refer to the same thing.
The amount of thermal energy available within wastewater is enormous (typically 20%-35% of total housing energy + up to 40% of low temperature heat used in commercial & industrial sectors gets turned into hot water which then goes into a city's sewers). So there are enormous amounts of low carbon heat available in every city's wastewater network. This heat energy is reliable, predictable, stable and flows through pipes located in the city (where heating & cooling energy is needed), and is contained within infrastructure which is already built.
But this energy is invisible and sadly normally simply flushed away everyday. For a sustainable world, we need to stop this energy waste and recycle the heat.
This heat energy is also increasingly a valuable asset. Recently the high level value of this energy was estimated for a large UK water utility at around £30 Million/year (based on actual prices being paid for wastewater heat energy at a UK site, applied to the possible energy available from the total sewage volumes managed by the Utility).
This website is a freely accessible and easily usable information portal, to display wastewater network heat maps showing in detail the thermal energy available within wastewater networks of any city in the world. The maps also shows where case studies are located and this portal provides supporting information on how to capture and recycle this energy.
We want to show how:
Our goal is that the wastewater energy available in every city in the world will be displayed here! An ambitious goal perhaps, but we simply ask "Why not?"
Currently we have wastewater network heat maps for three cities on the portal. These cities are: Christchurch - NZ, Dunedin - NZ, Nelson - NZ and we want more!
Our experience is that the barriers to recycling of this energy are:
1. Lack of awareness - many people just don't know about wastewater heat recycling. So it does not get included in policy development and energy planning processes.
2. Disconnects between different sectors. There are different sectors (we like to call them 'worlds') that need to come together to help each other and stop this tragic energy wastage. These worlds can be described as:
Simply put, the water world has this energy supply available but doesn't really have uses for it. The buildings world has uses for the energy, but doesn't know where it is located or how much there is available. Energy policy planners typically don't know about it so they ignore it in their planning processes.
To bring these worlds together, we need a bridge. This information portal and these heat maps are the bridge.
There is lots of great supporting information on wastewater heat recycling available on the FAQ page. These topics include:
Read how wastewater can be used for sustainable heating and cooling. How it can help cities transition away from fossil fuels. How it can help reduce urban heat island, improve air quality, save valuable water and in seismic regions, how it can help make buildings more seismically resilient.
Jump straight to the maps here
Information on how to navigate and use the heat maps is available on the Using The Heatmaps Page
Case studies showing operating examples of wastewater energy recycling are shown on the Case Studies Page
All of the data displayed in the heatmaps on this portal has been provided to wastewaterheat.online by the respective city.
Wastewaterheat.online cannot therefore be held responsible for the accuracy of any said data.
Case studies have been assembled either from publicly available information or personal knowledge of the site authors. If there are any corrections needed to the information provided on case studies please just contact us and let us know. If you have a case study that you would like to have added to the site, also please just let us know.
The people behind this site are a network of engineers and map makers who have extensive global expertise in this topic. We have people located in Europe, North America, Asia and Australasia. We are passionate about recycling wastewater heat. We have provided help to international organizations such as the UN, we have provided advice to national governments and national industry bodies. We have presented at many many conferences around the world and we want to help cities to help themselves.
We like this planet and we want to do what we can to protect it for ourselves and our for children and for future generations.